School Science Lessons
UNBiology3
2019-02-09
Please send comments to: J.Elfick@uq.edu.au

Blood, Digestion, Teeth, Growth, Metabolism
Table of contents

9.9.0 Blood and circulation, body temperature

9.180 Blood, Tests for blood

9.10.0 Digestion, teeth

9.11.0 Human body, growth, metabolism

9.9.0 Blood and circulation, body temperature
See: Physiology Blood, (Commercial)

See: Circulation, (Commercial)

9.215 Blood cells (humans)

9.215.1 Blood cells experiments

9.214 Blood constituents (humans)

9.219 Women feel colder then men

9.238 Osteoarthritis

9.182 Blood types, blood groups

15.8.5 Electrolytes in the blood and urine

24.7.4 Heat loss by the human body

9.239 Immunity, vaccinations

15.8.6 Soft drinks, carbonated beverages, fizzy drinks, sports drinks

9.219 Women feel colder then men


Experiments
9.214.1 Blood donors preparation
9.217 Blood flow in a fish
9.218 Blood flow in a frog
12.3.01 Blood pressure, sphygmomanometer
5.17 Body temperature (Clinical thermometer)
9.45.7 Body temperature, diurnal variation, sweat glands
12.8.15 Detect iron in fruit juice using black tea
9.216 Osmotic behaviour of red blood cells
9.180 Tests for blood
12.3.02 Water in blood
12.3.03 Hydrocortisone
12.3.04 Tattoo removal

9.180 Blood, Tests for blood
See: Physiology Blood, (Commercial)
See: Swabs, (Commercial)
9.184 Tests for haemoglobin, Hematrace test
14.3.1 Luminol tests for blood, Cu, Fe, Cn-
9.183 TMB test for blood

9.10.0 Digestion, teeth
See: Digestion, (Commercial)
7.8.3.5 Bile salts as an emulsifying agent
2.13 Our teeth (Primary)
9.222 Reflux and heartburn
6.6.3 Surface / volume ratio of soil particles
9.226 Teeth and toothpaste
17.5.19 Toothbrush friction

Experiments
9.223 Bile, Function of bile, bile salts
9.222.1 Digestibility of different protein foods
9.225 Digestibility of fats
9.224 Digestion in the intestines, pancreatin suspension
9.220 Digestion in the mouth, reaction of the enzyme ptyalin, salivary amylase
9.221 Digestion in the stomach, reaction of pepsin
9.236 Shakir strip and malnourished child
9.227 Small intestine, model with dialysis tubing
9.226.1 Teeth and toothpaste
9.211.1 Teeth scrapings

9.11.0 Human body, growth, metabolism
See: Human Body (Commercial)
15.0 Our body (Primary)
9.215 Adrenaline, epinephrine
9.228 Body Mass Index (BMI)
9.45.7 Body temperature, diurnal variation, sweat glands
9.219 Body temperature, Women feel colder then men
9.230 Bones and skeleton
9.238 Bones, Osteoarthritis
17.3.1.3 Catalase, Hydrogen peroxide with catalase enzyme in raw beef liver
9.55 Cheek cells, Human cheek cells
9.229 Children with diarrhoea, ORS special drink
9.234 Finger lengths
9.233 Fingerprints
9.240 Forensic science topics
4.2.11 Glycaemic index (GI)
9.237 Hair
9.235 Measure your weight
9.232 Muscles, use the muscles
9.5.10 Tests for urine, urine tests
19.1.20.4 Tests for glucose, urine test
19.1.20.12 Tests for urine, reagent dipsticks
9.141.2 Tests for reducing sugars in urine, Benedict's solution
9.5.10 Tests for urine, urine tests

2.13 Our teeth
| See diagram 9.226: Teeth 1
| See diagram 9.226.1: Teeth 2
| See diagram 9.226.2: Teeth 3
Teach the children to count the different kinds of teeth in your mouth.
Milk teeth have four incisors, two canines, two premolars, and one molar.
Permanent teeth have four incisors, two canines, two pre-molars, and three molars.
1. Sit in pairs and look in each others' mouth.
2. Count the biting teeth (incisors) How many teeth are there each side in the top jaw and in the bottom jaw?
3. Count the tearing teeth (canines) tell that dogs have big tearing teeth.
4. Count the grinding teeth (molars) tell the children that cattle have big grinding teeth.
5. Show how the teeth work.
5.1 Biting teeth more up and down to bite.
You can see your marks in some food.
5.2 To use tearing teeth you pull back, like a dog.
5.3 Pretend to chew something.
Describe how your jaws move. [They move from side to side, grinding the food into little pieces.]
6. Bring some skulls and teeth of animals to school.

5.17 Body temperature (Clinical thermometer)
See: Thermometers clinical thermometers, (Commercial)
See diagram 23.7.02: Clinical thermometer
Measure the temperature of the body with a clinical thermometer.
Use a clinical thermometer and not any other type of thermometer.
You will also need a glass of water with some antiseptic in it.
Make sure that you can read the thermometer.
Normal body temperature is marked with an arrow of 37oC.
In a clinical thermometer there is a constriction in the bore.
This allows the mercury to expand (rise) showing a rise in temperature but it does not allow the mercury to contract (fall) again.
This lets you take a thermometer out of a student's mouth and does not give a falsely low reading.
To move the mercury down again you have to flick the thermometer with a quick turn of their wrist.
Practise flicking it to make the mercury go down.
Do not drop it on a concrete floor.
Practise flicking the mercury down standing on the grass.
Do not be alarmed at small differences in temperature between people.
In women, the body temperature changes with the menstrual cycle.
Take the temperature of each child in the class.

1. Show the clinical thermometer.
Have they seen it before?
Explain that this measures how hot your body is.
In healthy people the body has a constant temperature: 37 degrees Celsius (37oC) but it can vary slightly.
It is lower when you wake up and it is higher if you run about a lot.
If the body temperature is much higher or lower this means that you are sick.
Draw the temperature scale on the chalkboard.

2. Take your own temperature.
Draw an arrow on the chalkboard diagram to show your own temperature, e.g. 37.2oC.

3. Flick down the mercury.
Wash the thermometer in antiseptic then read the temperature with each child.
Tell each child to draw an arrow on the chalkboard to show their temperature.
[The average temperature is 37oC, some temperatures are a bit higher or lower.]

4. Compare these two groups of temperature readings:
6.1 Adult / child / babies,
4.2 Boys / girls,
4.3 Lying down after running around the classroom.
Make a table and compare your readings for each group.
Besides this you could try outside the class by going to a nearby Health Centre or hospital to collect information on temperature
readings.

6.14 Shakir strip, malnourished child
See diagram 9.236: Shakir strip
See 15.8.5: Electrolytes in the blood and urine
Find malnourished small children by measuring their arms with the Shakir strip.
People who do not have enough food or do not have the correct amounts of energy food, growth food, and healthy food are
said to be malnourished.
Malnourishment of young children, especially after weaning, can be very dangerous.
They may get sick and die or they cannot learn much when they go to school.
It is not easy to tell whether a child is really undernourished or has a temporary sickness.
This problem has been solved by the Shakir strip used in many countries.
When babies are about one year old, they have much fat under the skin of their arms.
When you are five, this fat is not there but there is much more muscle.
This means that the circumference of the upper arm is almost the same between the ages of one and five.
If you measure the middle of the upper arm of children between the ages of one and five, you can find the malnourished children.
Instead of a tape measure you can use a piece of string or a strip of material that does not stretch, e.g. old X-ray film.

Children between the ages of one and five should not be malnourished otherwise they may get sick and die.
Malnourished children may not learn much when they grow up.

Doctors have found a way to tell if children are malnourished by using a marked tape called the Shakir strip.
It is one cm wide.
The circumference of the upper arm is as follows:
Table 6.14 Shakir Strip
| Circumference of Upper Arm | Colour Zone / Health of Child |
| Greater than 135 cm | green zone | Healthy child, not malnourished |
| Between 125 and 135 cm | yellow zone | Child probably malnourished |
| Less than 125 cm | red zone | Child certainly malnourished |

Use of the Shakir strip
1. Cut a strip of paper the length of the page and one cm wide.
At six cm from one end mark 0 cm.
Then mark it at 12.5 and 13.5 cm.
Colour 0 to 12.5 cm red, 12.5 to 13.5 cm yellow and more than 13.5 cm green.
Give the children a cardboard toilet roll centre or a thin tube to measure.
Are they correct?

2. Take the Shakir strip home and measure the arms of all the children with age one to five years.
If you find any children in the yellow or red measurement, tell the teacher the next day.

3. Recently-weaned children may be malnourished if there is no suitable food for them or mothers do not prepare proper food.
Do a class or community experiment on this for one to five year old children and then record a graph to compare malnutrition rates.

Treat diarrhoea
1. Care for younger children with diarrhoea by replacing water lost because of dehydration.
In many areas, diarrhoea is the most common cause of death in small children, and is specially frequent in babies between six
months and two years.
It is more common and dangerous in children who are malnourished.
Bottle fed babies have diarrhoea more often than breast fed babies.
Diarrhoea can be prevented by: breast feeding babies for as long as possible, good nutrition and cleanliness.
If you are a good teacher, you can teach your children how to care for younger children with diarrhoea.
Use sugar, salt, water, spoons, cups.

2. Give children the drink, coconut water or "special drink" when diarrhoea begins.
A child should drink for each time a stool is passed.
If the child vomits up the drink, keep giving more drink because some of it will stay in the stomach.
Give it in sips every two or three minutes.
If the child does not want to drink, gently insist that the child tries to drink something.
Keep giving the drink every two or three minutes, day and night until the child urinates normally, every two or three hours.
Older children and their mother can take turns through the night.
Warning signs!

3. Take the child with diarrhoea to the Health Centre if:
1. the child shows any signs of dehydration,
2. cannot drink or,
3. will not drink,
4. makes no urine for six hours,
5. has diarrhoea too often so cannot drink one glass per stool,
6. has blood in the stool,
7. diarrhoea lasts more than two days.

Diarrhoea means frequent watery stools.
Often children with diarrhoea also have vomited and have a swollen belly with cra mps.
The stools smell different from normal stools (toilet).

Children die of diarrhoea usually because their bodies lose too much water.
This loss of water is called dehydration.
All living things contain much water.
For example, if you bring two cut plants to school, and put one in water and the other not, you will see that one will wilt.
A baby with diarrhoea loses water like the wilted plant.

Signs of dehydration:
1. almost no urine that is dark yellow,
2. dry mouth,
3. sunken tearless eyes,
4. sunken soft spot (fontanelle), on top of baby's head,
5. skin loses its stretching.
If you lift up the skin and you can still see the fold after you let go, the child is dehydrated.

The most important part of treatment is to replace the water lost through diarrhoea and vomiting.
Medicines are often not very effective, but drinking coconut water puts water back into the child.
Also children with diarrhoea must be given food, if they can take it, to help their bodies fight the sickness.

5. The Special Drink:
Make the Special Drink from sugar, salt and water.
Mix: sugar + salt + water.
Use one level teaspoon of sugar and add a little salt at the end of the spoon in one glass of water.
Before giving the drink taste it, it should be no more salty then tears in the eye.
Let the children make the Special Drink and taste it.
Extra Activity: Visit a Health Centre to see how children are treated for diarrhoea and dehydration.

9.211.1 Teeth scrapings
1. Put white scrapings from the teeth on a microscope slide.
Examine the scraping under a microscope and look for any bacteria.
You may have to seek approval to work with samples from the human mouth because diseases may spread.
Wear safety glasses and disposable surgical gloves.

2. Use a tooth pick to dislodge material on the tooth surface at the gum line or between the teeth and put in a drop of water on a
clean slide.
Use the blunt end of the tooth pick to squash the material into tiny pieces.
Fix the smear by briefly passing the slide through a flame.
Stain the smear with a drop of methylene blue.
Rinse the smear with tap water for 2 seconds to remove excess stain then blot it with absorbent paper.
Dry the smear by briefly passing the slide through a flame.
Examine the smear under a microscope.

9.5.10 Tests for urine
See: Physiology Urine, (Commercial)
See 19.1.20.4: Prepare artificial urine sample
If testing human urine, the medical interpretation can only be done by an experienced medical practitioner.
Some school systems do not allow use of human urine in a school laboratory.

Experiments
1. Record the volume of urine produced.
Quantity of urine is 700 to 2 500 mL per day
Less urine is produced, 1.1 during the night, 1.2 after small intake of food or drink, 1.3 after sweating or fever, 1.4 on a hot day,
1.5 after diarrhoea decreases salts and water in the body, 1.6 after vomiting, 1.7 if kidney diseases, 1.8 if obstruction in urinary tract.
More urine is produced, 1.9 during the day, 1.10 after large intake of food or drink, 1.11 on a cold day, 1.12 after kidney failure.

2. Heat urine
Alchemists heated urine because they thought of some connection between its yellow colour and gold.
Also, they thought that the glow from heating evaporated urine was a miraculous light from our bodies.
Leave 4 litres of urine to evaporate in a remote place to leave about 20 g of almost colourless crystal residue.
Heat the residue in a Bunsen burner and collect the condensed vapour.
Test the vapour with litmus paper and hydrochloric acid to show it contains ammonia.
Leave the dark grey evaporate to cool.
Use a platinum wire to heat some evaporate in the hot blue flame of the Bunsen burner.
Note the yellow light of sodium and the fainter carmine red light of calcium.
Dissolve some evaporate in water and add silver nitrate solution to form a milky white precipitate, indicating chloride, and a
brown residue.
Use a mortar and pestle to grind together the grey burnt urine residue with fine charcoal powder and heat the mixture strongly.
A lighted taper placed in the gases given off produces a blue flame as carbon monoxide burns to form carbon dioxide.

3. Colour of urine
Betanin, C24H26N2O13, (betanidin-5-O-beta-glucoside) (Eat extra beetroot to cause coloured urine)
Urine has a yellow amber colour and is clear and transparent when first voided, but the colour darkens on standing caused by
oxidation of colourless urobilinogen to coloured urobilin.
The red-brown colour is caused by urochrome and uroerythrin pigments.
Colour may be changed by eating beetroot (red), rhubarb (orange tint), tetracyclines (yellow), methylene blue (green), some
bacterial infections (green tint), vitamin B tablets (vivid yellow).
Clouded urine caused by some bacterial infections, pus, phosphates, and possibly some foods.
Urine is transparent at body temperature but may precipitate ureates when cooled.

3. Odour of urine
Aromatic odour but distinct odour if asparagus is consumed, and an acetone odour if diabetic ketoacidosis (fatty acids breaking
down to form ketone bodies).

4. Specific gravity (relative density)
Usually 1.003 to 1.030, lower if excessive drinking of water, diabetes insipidus, renal failure.
Higher if dehydration, heart failure, high level of glucose (glycosuria).
Freezing point can be used to measure concentration of solute particles per unit of solvent.
The highest concentration occurs in the first urine passed on rising in the morning.

5. pH
Usually acid, pH 4.5 to 8.

6. Proteins, boiling test
Normally < 100 mg/24 hours.
Less protein after exercise, inflammation, kidney infection.
Tests for protein with "Albustix" reagent strip.
If urine sample is alkaline use litmus paper and add drops of 10% acetic acid until urine is pH 5.
Hold the test-tube at an angle and heat the top of the solution to boiling, then view it against a dark background.
A cloudy solution shows the presence of protein or phosphates.
Urine is more alkaline after boiling because of loss of carbon dioxide.
Add 10% acetic acid.
If the precipitate disappears the cloudiness is caused by phosphates.
If the precipitate remains, the cloudiness is caused by proteins.

8. Glucose
Should be none but present if diabetes mellitus or excess corticosteroid hormones (Cushing's disease)
Tests for sugar, Benedict's tests for reducing sugars 9.141
Tests for glucose 19.1.20.4
Tests for glucose and starch with "Testape" 9.182
Should be no ketones.

9.45.7 Body temperature, diurnal variation, sweat glands
See: Sweat Glands (Commercial)
Surface temperature sensor, measures skin temperature,
Body temperature is an example of a circadian rhythm, regular cyclic activity about 24 hours long and the regulator of the sleep / wake
cycle.
In a healthy person, the average temperature for healthy adults is 36.3oC to 37.1oC for males, and 36.5oC to 37.3oC for females.
The highest temperatures are between 6.00 a.m. and 6.00 p.m. and the lowest temperatures are between 2.00 a.m. and 6.00 a.m.
An oral temperature between 35.9C and 37.5C is usually considered normal.
Body temperature is sensitive to hormone level in the female.
Blood vessels in the skin expand to carry the excess heat to the skin surface.
Also, evaporating sweat cools the body as sweat absorbs the heat of vaporization.
Blood vessels in the skin contract to reduce loss of heat.
Also, involuntary shivering, contraction of the muscles, generates more heat.
A rectal or ear temperature is 0.3oC to 0.6oC higher than an oral temperature reading.
An armpit temperature is 0.3oC to 0.6oC lower than an oral temperature reading.
The forehead temperature is the same temperature as the arterial blood supply under the skin.
The forehead temperature is said to be more accurate that ear temperature because the position of the probe in the ear canal in
sequential readings is usually inconsistent.
The forehead thermometer scans the forehead area for the temporal artery by positioning the probe flush on the centre of the forehead,
midway between the eyebrow and the hairline.
Fever is present if:
rectum temperature or ear temperature is greater than 38.0oC,
mouth temperature is greater than 37.5oC,
under the arm temperature is greater than 37.2oC.
A lady on a diet finds that after eating her body temperature drops and she feels very cold.
She probably experiences what doctors call a post-prandial effect to a rush of blood to the stomach leaving the skin feeling cool as
blood carrying body heat is shunted away from below the skin.
So she should eat her meals slowly.
Similarly, she should not go swimming straight after consuming a heavy meal because the skeletal muscles may be starved of enough
oxygen for rapid contraction to cause cramps and death by drowning.

Experiments
1. Measure the temperature under your tongue every hour and draw a graph of the results.
(A human tongue can be frozen to cold metal enough to risk pulling off skin and muscle when the person tries to remove it.
So do not lick very cold metal!)

2. Note the changes in your body at high ambient temperature.
2.1 Capillaries in the skin swell (vasodilation) to release more heat.
2.2 The arrector pili muscles in the skin pull the hairs to make them lay flat down on the surface of the skin and allow air to circulate
freely over the skin.
2.3 Sweat glands secrete sweat onto the skin surface where the latent heat of vaporization of water is lost.
Animals, e.g. dogs, can lose heat by panting.
Try to lose heat by panting, inhaling and exhaling rapidly.

3. Note the change in your body at low ambient temperature.
3.1 Capillaries in the skin constrict (vasoconstriction) to release less heat.
3.2 The arrector pili muscles in the skin pull the hairs up to not allow air to circulate freely over the skin.
This action of the arrector pili muscles causes "goose pimples".
Animals can increase the thickness of their coats and birds can ruffle their feathers.
3.3 The sweat glands stop secreting and the hypothalamus of the brain sends messages to internal muscles to contract violently, and
cause shivering.
The oxygen consumption increases 2 to 5 times and the internal organs are warmed.
Hypothermia begins when body temperature drops to 35C when normal metabolism slows until the internal organs no longer function,
and the person dies.

9.182 Blood types, blood groups
See: Physiology Blood, (Commercial)
Antigen: A foreign substance causing production of an antibody by an immune response
1. ABO system (AB, A, B, O types)
2. Rhesus blood group system, Rh system, Rh-positive blood contains a D-antigen, Rh-negative blood contains no Rh antigen.
A Rh-positive foetus in a Rh-negative mother my develop haemolytic disease from the Rh antibodies produced in he mother blood.
So each blood type in the ABO system can be labelled + and + for the Rhesus system, AB+, AB-, A+, A-, B+, B-, O+ and O-.
This blood group system was named after the Rhesus monkey, Macaca mulatta, where a similar antigen was found.

Type AB+, 3% of population, A and b antigens on red blood cell, called universal recipient because no antibodies in plasma,
so AB plasma, + or -, can be transfused into any other patient,
In Caucasians:
Type AB-, 3% of population.
Type A+, 1% of population, A antigen on red blood cell, B antibody in plasma.
Type A-, 7% of population.
Type B+, 9% of population, B antigen on red blood cell, A antibody in plasma.
Type B-, 2% of population.
Type O+, 37 % of population, most common blood type, no antigens on red blood cells,  A and B antibodies in plasma.
Type O-, 8% of population, called universal donor, because no antigens on red blood cells and no Rh antigen
African-Americans have O+, 47% and B+, 18%.
Hispanic people have O+, 53%.
Asians have B+, 25%.
Any blood transfusion containing foreign antibodies will be agglutinated by the antibodies in the recipient's plasma.
ABO blood typing is not sufficient to prove or disprove paternity or maternity, so do not encourage children to discuss the blood types
in their family.

9.183 TMB test for blood
See: Physiology Blood, (Commercial)
The Tetramethylbenzidine Presumptive Test for Blood is based on President's DNA Initiative, DNA Analyst Training, Laboratory
Training Manual, Protocol 2.19.
This laboratory protocol (or part thereof) has been provided as an example of a laboratory SOP, courtesy of the National Forensic
Science Technology Center.
It has been included for training and example purposes only.
The TMB test is a catalytic test based on the peroxidase-like activity of haemoglobin.
Haemoglobin can cleave oxygen molecules from hydrogen peroxide and catalyzes the reaction from the reduced form of
tetramethylbenzidine to the oxidized blue-green coloured product.

Prepare the tetramethylbenzidine (TMB) reagent
Weigh out 0.2 grams of TMB.
Add to a 50 ml beaker.
Measure out 10 ml glacial acetic acid and add to the TMB, Mix thoroughly until the TMB is dissolved.
Store refrigerated for up to one week
Prepare hydrogen peroxide 3% solution: Measure out 10 ml of 30% hydrogen peroxide.
Add 90 ml of deionized water.
Store at room temperature or refrigerated for up to one year.

Procedure
Step 1. Swab suspected blood stain with clean filter paper or a swab, which may be moistened if necessary with deionized water,
ethanol or saline.
Apply 1-2 drops of the TMB reagent.
Note any blue-green colour change.
A blue-green colour change at this step indicates a chemical oxidant and the test should be considered inconclusive.
If there is no colour change, proceed to the next step.
Step 2. Add 1-2 drops of 3% hydrogen peroxide.
Note any immediate blue-green colour change.
6. An immediate blue-green colour change indicates a positive result.
No colour change indicates a negative result.
A negative result indicates that either no blood is present or is below the limit of detection of the test.

9.184 Tests for haemoglobin, Hematrace test
The ABAcardHematrace Test for the Identification of Human Haemoglobin is based on President's DNA Initiative, DNA Analyst
Training, Laboratory Training Manual, Protocol 2.20.
This laboratory protocol (or part thereof) has been provided as an example of a laboratory SOP, courtesy of the National Forensic
Science Technology Center.
It has been included for training and example purposes only.
The ABAcardHemaTrace is a testing device used to aid in the possible identification of human blood by detecting the presence of
human haemoglobin.
If human haemoglobin is present in the sample, its antigens will react with the mobile monoclonal antihuman Hb antibodies in the area
marked "S".
This will form a mobile antibody-antigen complex, which migrates through the device toward the area marked "T".
The "T" area contains stationary polyclonal antihuman antibodies, which capture the mobile antibody-antigen complex.
This forms an antibody-antigenantibody sandwich.
The antibodies are labelled with a pink dye and upon aggregation of these antibodies, a pink line forms in the "T" zone indicating the
presence of human haemoglobin in the sample.
This test device also contains an internal positive control.
In the area marked "C" there are stationary antiimmunoglobulin antibodies that bind excess antihuman Hb monoclonal antibodies but
do not bind to the antibodies in area "T".
The captured pink dye particles will form a pink line in area "C" indicating the test worked properly.
The presence of two pink lines, one in area "T" and one in area "C" indicate a positive result.
The presence of only one pink line in area "C" indicates a negative result.
If there is no pink line in area "C" then the test is invalid.
This test has shown that false positives may occur with ferret blood.

9.214.1 Blood donors preparation
See: Physiology Blood, (Commercial)
The students at the University of Queensland are given the following advice before giving blood.
Compare this advice to that given in your region or local hospital.

1. To prepare yourself before donating, increase fluids (preferably water or juice), have a good size meal, and bring some form of
personal photo ID.

2. If the following apply to you, please phone our the Australian Red Cross Blood Service to discuss your eligibility to donate:
You have a sore throat or the beginnings of a cold, are taking antibiotics, have taken your last antibiotic less than 5 days ago, have had
a tattoo in the last twelve months, have lived in England for a cumulative 6 months or more between 1980 and 1996 as a precaution
against transmission of mad cow disease, have any history of heart disease, stroke or epilepsy, are pregnant or are a female with a child
younger than 10 months of age.
Comprehensive information on excluded donors can be obtained from the Red Cross website:

9.215 Blood cells
See: Physiology Blood, (Commercial)
See diagram 9.215: Human blood cells (Romanowsky stain)
1. Red blood cells, erythrocytes: no nucleus, biconcave discs, haemoglobin, from red bone marrow, live 80 to 120 days until
destroyed in spleen and liver.
Haeme, heme, C34H32FeN4O4, is the colour part of haemoglobin, in tissues and hemeproteins.
See diagram: Heme
2. White blood cells, leucocytes
3. Granulocytes, granular cytoplasm, multilobed nucleus
3.1 Neutrophils, 56% of total white blood cells, ingest bacteria
3.2 Eosinophils, 2.7% of total white blood cells, allergy reaction
3.3 Basiphils, produce heparin (blood clotting) and histamine (capillary permeability)
4. Monocytes, phagocytes in tissues after leaving blood
5. Lymphocytes, 34% of total white blood cells, produce antibodies

Human blood contains red blood cells (erythrocytes) white blood cells (leukocytes) and platelets (thrombocytes).
The erythrocyte count is 4.2 to 5.9 X 1012 cells per litre.
The hematocrit, packed cell volume, measures the proportion of blood volume occupied by red blood cells, males 40% to 54%,
females 37% to 47%.
The ratio of white blood cells to red blood cells constitutes 1 white blood cell for every 600 to 700 red blood cells.
White blood cells are larger than red blood cells and have nuclei with variable shapes.
Platelets are irregular in shape and are usually seen in small groups like piles of coins.
Platelets help the blood clotting processes.
Blood cells are suspended in the straw-coloured blood plasma, a solution of inorganic salts and proteins.
Blood serum is blood plasma with fibrinogen and other blood clotting agents removed.
A full blood count (FBC) made microscopically using a haemocytometer slide and a blood-diluting pipette is used for diagnosing
whether the number of blood cells is abnormally high or abnormally low, or whether the cells themselves are abnormal.
It can be used to measure the amount of haemoglobin in the blood, the number of red blood cells (red cell count), number of blood
cells / total blood volume (hematocrit or packed cell volume), volume of red blood cells (mean cell volume), mean of haemoglobin in
the red blood cells (mean cell haemoglobin), number of white blood cells (white cell count), different types of white blood cells as
percentages (leucocyte differential count), number of platelets.
Haemoglobin can be estimated by dilution of the blood and comparison with colours in a matching box.
The "quaternary proteins" have four joined tertiary proteins, e.g. haemoglobin.
The "transition metals" form complex ions and often have catalytic activity, e.g. Fe in the complex haemoglobin molecule.

When capillaries are broken blood leaks into the surrounding tissue and the haemoglobin produces the red purple colour of a bruise.
The haemoglobin breaks down into green biliverdin and yellow bilirubin so changing the colour of the bruise.
Excess bilirubin in the skin causes the yellow colour of jaundice, e.g. hepatitis and some new born babies.
Bilirubin can be broken down by ultraviolet light, a treatment for bruises.

9.215.1 Blood cells experiments
See: Physiology Blood, (Commercial)
3.28 Prepare Giemsa stain
3.19 Prepare Wright's stain
Do not take blood samples from other people in the class or from yourself!
Use frog blood, mammalian blood from a slaughterhouse or butcher shop or whole blood from a hospital.
You may have to seek approval to work with animal blood or human blood, because blood may spread disease.
Wear safety glasses, protective clothing and disposable surgical gloves for handling animal tissue and blood products.
Instead of using human blood, use prepared slides of mammalian blood cells purchased from a laboratory supply company.
Prevent mammalian blood clotting by adding a 2% sodium citrate solution in the ratio 1 part of solution to 4 parts of blood.

1. Study frog blood and mammalian blood with a microscope for a comparison of blood cells with a nucleus and without a nucleus.

2. Make a staining bath.
Push two pairs of paper clips opposite each other halfway down the side of a flat transparent dish, so that each clip forms an eyelet
above the edge of the dish.
Push a long glass rod through each pair of eyelets and then push the paper clips to secure the glass rods in a parallel position.
The glass rods become a bridge for the flat transparent dish staining bath.

3. Put the slide with the drop of blood at an acute angle about one centimetre from the shorter edge of a second slide on the bench.
Push the slide along the second slide to spread the blood evenly as a smear over its surface.
Allow the smear to dry then place it, smear upwards, across the bridge of the staining bath.
For fixing the air-dried blood smear, cover the entire surface of the slide with methanol, methyl alcohol.
After three minutes, tip off the methanol and cover the slide with dilute Giemsa solution
After twenty minutes tip off the Giemsa solution, rinse under running water then leave to dry.
Examine the preparation under high power.

Observe the following:
3.1 Red blood corpuscles, erythrocytes, with no nuclei, have dumbbell shape seen in profile and pale in the centre is seen from broad surface.
3.2 Nucleated white blood corpuscles, leukocytes.
3.3 Irregular-shaped platelets, thrombocytes.
Red blood cells will appear pinkish grey, platelets will appear deep pink, and white blood cells will have purple blue nuclei and a
lighter cytoplasm.

4.1 Fill a 100 mL graduated cylinder to the 100 mL mark with mammalian oxalated blood purchased from a qualified supplier and
allow it to stand.
You may have to seek approval to work with animal blood or human blood because blood may spread disease.
Wear safety glasses, protective clothing and disposable surgical gloves for handling animal tissue and blood products.
Within 24 hours, the blood separates into an opaque, red fraction at the bottom with a yellowish liquid above.
For horse blood, the red fraction is 55% by volume.
Oxalated blood usually contains potassium oxalate.

4.2. Transfer a drop of the yellow liquid to a microscope slide with a glass rod.
Apply a coverslip and examine under high power.
Note the non-suspended bodies.

4.3. Pour the yellow liquid only out of the graduated cylinder.
Use a glass rod to transfer a drop of physiological (0.9%) saline (sodium chloride in deionized water) to a microscope slide.
Add to this drop some opaque red sediment from the measuring cylinder and mix well.
Apply a coverslip and examine under high power.
Note the numerous round pale yellow-red cells without nuclei, the red blood corpuscles, erythrocytes.
They appear shaped like a dumbbell when viewed from the side because of the central indentation of both sides.
Some lie close together like cylindrical heaps of coins.

4.4 Let the oxalated blood stand so that the blood cells settle.
The yellow blood plasma above contains no corpuscles or other bodies.
The white blood corpuscles can be seen only if the iris diaphragm is almost closed.
Usually, they are stained with Giemsa stain (methylene blue and eosin).

9.216 Osmotic behaviour of red blood cells
Experiments using live human blood cells may not allowed in some school systems.
1. Use a glass rod to transfer one drop of deionized water on a microscope slide.
Let a drop of blood fall into the drop of water on the slide.
Mix the blood and water well.
Place a coverslip over the mixture and examine the preparation immediately under a microscope, magnification 400 X.
Describe any changes in the red blood cells.
The contents of the red blood cells are hypertonic to the outside solution so the blood cells swell because of endosmosis, gain of water.

2. Use a glass rod to transfer one drop of deionized water on a microscope slide.
Let a drop of blood fall into the drop of water on the slide.
Add one drop of 6% sodium chloride solution to the slide and mix well.
Apply a coverslip and examine under a microscope, magnification 400 X.
Describe any changes in the red blood cells.
The contents of the red blood cells are hypotonic to the outside solution so the blood cells shrink because of osmosis, loss of water.

3. Use a glass rod to transfer one drop of deionized water on a microscope slide.
Let a drop of blood to fall into the drop of water on the slide.
Add one drop of 0.9%, sodium chloride solution to the slide.
Apply a coverslip mixture and examine under a microscope, magnification 400 X.
Compare the observations made in the three experiments.
The 0.9% salt solution is called physiological saline, salt solution.
Describe any changes in the red blood cells.
The contents of the red blood cells are isotonic with the outside solution so the blood cells stay the same size with no gain or loss of water.

9.217 Blood flow in a fish
See: Physiology Blood Fish, (Commercial)
See: Circulation, (Commercial)
See diagram 9.3.65.1: Fish circulation
Study the circulatory system of a fish.
Show the circulation of blood in the tail of a fish.
Wear safety glasses, protective clothing and disposable surgical gloves for handling animal tissue and blood products.
You may have to seek approval to work with live fish.
Put a goldfish, 5 cm long with a light colour caudal fin in a beaker containing 200 mL of 1.2% ethyl carbamate solution.
Be careful! Ethyl carbamate is a possible carcinogen so work in a well-ventilated area.
The fish becomes paralysed.
Remove it from the solution and lay it on a glass dish.
Cover the entire body of the fish, except the caudal fin, with wet absorbent paper placed close to the skin.
Drop water from a pipette on the caudal fin to keep it moist.
Put the caudal fin on the stage of a microscope.
Use low power to see the movement of blood through the capillaries and the movement of the red blood corpuscles.
Put the fish back in water where it will become mobile again.

9.218 Blood flow in a frog
See: Physiology Blood Frog, (Commercial)
See: Frogs (Commercial)
See diagram 9.3.65.2: Frog circulation
Study the circulatory system of a frog and observe the blood cells.
Wear safety glasses, protective clothing and disposable surgical gloves for handling animal tissue and blood products.
You may have to seek approval to work with live frogs or toads.
Be careful! Do not use frogs or toads that release toxins.
Wrap the frog in a wet cloth and pin it to a soft board with a hole in the cloth for observing with a microscope.
Mount the webbing between the toes of the frog under the hole and put the board and frog on a microscope stage.
Observe blood cells squeezing through the extremely small blood vessels of the thin webbing between the toes.

9.220 Digestion in the mouth
See: Physiology Digestion, (Commercial)
Reaction of the enzyme ptyalin, salivary amylase
9.141 Benedict's test
9.142 Fehling's test
You may have to seek approval to work with human saliva because it can spread disease.
Instead of using human saliva, use salivary amylase from a laboratory supply company.

Experiments
1. Put 10 mL of 1% starch solution in three test-tubes standing in beakers containing water at 40oC.
1.1 Add 5 drops of dilute (10%) hydrochloric acid to test-tube.
1.2 Add 5 drops of human saliva to test-tube.

2. 2. Test-tube 3, the control, contains only the starch solution and is the control.
Every 30 seconds remove a drop from each test-tube and add 2 drops of dilute iodine solution to do the iodine tests for starch.
Repeat the experiment with beakers of water heated to 100oC.
Saliva contains the enzyme, salivary amylase.

3. Cut the crust off a slice of white bread and divide the rest of the slice into two pieces.
Chew the first piece quickly and swallow it as soon as possible.
Chew the second piece for 5 minutes before swallowing.
Describe the tastes of the two slices.

4. Do not make any chewing motion, then let 5 mL of saliva drop from the lower lip into a beaker.
Dilute the saliva with an equal amount of water.
Put 10 mL of starch solution into each of three test-tubes.
Do the iodine tests for starch, drop by drop, into each test-tube, until a clear blue colour appears to show the presence of starch.
4.1 Put diluted saliva into test-tube 1, then do Fehling's tests for simple sugars.
4.2 Put an equal volume of water into test-tube 2, then do Fehling's tests for simple sugars.
4.3 Do Fehling's tests for simple sugars on the contents of test-tube 3, the control.
Compare the colours of the contents of the three test-tubes.

9.221 Digestion in the stomach, reaction of pepsin
See: Physiology Digestion, (Commercial)
You may have to seek approval to work with human saliva because it can spread disease.
Instead of using human saliva, use salivary amylase from a laboratory supply company.
Pepsin enzyme is secreted into stomach to hydrolyse protein linkages in proteins.
Gastric juice contains the enzyme pepsin and 0.2-0.5% hydrochloric acid.
You may notice the acid in the gastric juice if you belch.
The pain of "heartburn" (reflux oesophagitis) is caused by excessive gastric juice irritating the lower oesophagus.
1. Add the following solutions to four test-tubes:
1.1 Put 10 mL of water in the first test-tube.
1.2 Put 9 mL of 1% pepsin solution + 1 mL of water in the second test-tube.
1.3 Put 9 mL of water + 1 mL 5% hydrochloric acid in the third test-tube.
1.4 Put 9 mL 1% pepsin solution + 1 mL 5% hydrochloric acid in the fourth test-tube.
Put a piece of boiled fish into each test-tube.
Put the test-tubes in a beaker of water at 37oC.
Try to keep the water in the beaker at that temperature overnight, then compare the contents of the test-tubes.

2. Put uncooked starchy food, e.g. flour, rice, spaghetti, potato, in a first test-tube.
Put an equal volume of the same food cooked in a second test-tube.
Add the same volume of diluted saliva solution to both test-tubes then stir them with glass rods.
Leave for two hours.
Compare the contents of the two test-tubes.

3. Cut cooked meat, uncooked meat, egg, and cheese into very small pieces.
Wear safety glasses, protective clothing and disposable surgical gloves for handling animal tissue and blood products.
Put the cut food into different test-tubes.
Add 5 mL of 1% pepsin solution and 2 drops of dilute (10%) hydrochloric acid to each test-tube.
Shake the test-tubes occasionally for one hour.
Compare the contents of the four test-tubes.
A similar process occurs in the human stomach.

9.222 Reflux and heartburn
Reflux, gastro-oesophageal reflux (GORD), is caused by stomach acid rising into the oesophagus and irritating it as a painful burning
sensation, heartburn.
Heartburn has nothing to do with the heart.
The burning sensation may be accompanied by a bitter taste in the throat, burping, bloating and difficulty of swallowing.
The contents of the stomach are normally prevented from moving into the oesophagus by the lower oesophageal sphincter muscle
(LOS) that acts as a valve to let food enter the stomach but prevents the acid contents from reaching the sensitive oesophagus.
Heartburn occurs in many people after a large meal and when lying down.
It may be caused by a particular food, e.g. chocolate, peppermint, deep fried foods, onions, garlic, coffee, alcoholic beverages, citrus
juice, soda water, tomatoes, and spices.
The most common immediate treatment is to take antacids as tablets, e.g. aluminium hydroxide, magnesium hydroxide, calcium
carbonate, bismuth subsilicate, or as a solution, e.g. sodium bicarbonate.
Persistent heartburn requires medical attention.

9.222.1 Digestibility of different protein foods
Fill four test-tubes with 9 mL of 1% pepsin solution + 1 mL of 5% hydrochloric acid.
1. Put a piece of boiled egg white in the first test-tube.
2. Put an equal volume of boiled fish in the second test-tube.
3. Put an equal volume of low fat cheese in the third test-tube.
4. Put an equal volume of lean boiled beef in the fourth test-tube.
Put all the test-tubes in a beaker of water at 37oC.
Leave for one hour then compare the contents of the four test-tubes.

9.223 Function of bile, bile salts
Bile salts emulsify fats to increase their surface area for digestion. Ox bile can be purchased from a laboratory supplier.
Add 10 drops of olive oil to the first test-tube that is half full of water.
Hold the thumb over the mouth of the test-tube, shake it several times then place it in a test-tube rack.
Add an equal volume of 40% ox bile solution to the second test-tube that is a quarter full of water.
Add 10 drops of olive oil.
Hold the thumb over the mouth of the test-tube and shake it several times, then place it in a test-tube rack.
Compare the contents of the two test-tubes.

9.224 Digestion in the intestines, pancreatin suspension
See: Physiology Digestion, (Commercial)
The pancreas secretes several enzymes in the pancreatic juice.
Pancreatin suspension is a mixture of pancreatic enzymes.

Experiments
1. Fill two test-tubes each with 5 mL of 1% starch solution.
Add 2 drops of dilute iodine solution to do the iodine tests for starch.
1.1 Add 5 mL of water to the first test-tube.
1.2 Add 5 mL of 1% pancreatin suspension to the second test-tube.
Note: digestive enzymes can be purchased by laboratory suppliers.
Cover each test-tube with the thumb, invert it to mix the contents, and put them in a test-tube rack.
Compare the contents of the two test-tubes.

2. Fill four test-tubes with 9 mL of 1% pancreatin suspension.
2.1 Put a piece of boiled egg white in the first test-tube.
2.2 Put an equal volume of boiled fish in the second test-tube.
2.3 Put an equal volume of low fat cheese in the third test-tube.
2.4 Put an equal volume of lean boiled beef in the fourth test-tube.
Put all the test-tubes in a beaker of water at 37oC.
Leave for one hour then compare the contents of the four test-tubes.
The pieces of food in the test-tubes gradually disintegrate.

9.225 Digestibility of fats
The bile and the enzymes of the digestive juices can attack and decompose melted fats more easily because of their larger surface area.
Prepare three squares of copper gauze, 150 X 150 mm.
1. Put a cube of margarine on the first gauze square.
2. Put an equal volume of lard (pig fat) on the second gauze square.
3. Put an equal volume of beef suet (solid kidney fat) on the third gauze square.
Fold each gauze square to enclose the sample of fat completely, then put each in a separate beaker of water at 37oC.
Put the beakers on black paper.
Look down to observe the melting fats.
Note droplets of fat rising to the surface of the warm water.
Note which fat is the most digestible.

9.226 Teeth and toothpaste
| See diagram 9.226: Temporary teeth, "milk teeth", Permanent teeth
| See diagram 9.226.1: Order of new teeth breaking through gums
| See diagram 9.226.2: Molar tooth V.S.
Enamel, dental enamel, bone, teeth and toothpaste, calcium hydroxyl apatite, calcium hydroxyapatite.
1. Teeth are important for the first stages of the digestion process.
However, tiny particles of food collect plaque (plaque, Dutch: plakken, to stick) around them and provide a breeding place for bacteria.
The breakdown of sugary foods by bacteria, e.g. Streptococcus mutans, in the mouth produces organic acids that dissolve the teeth
and causes tooth decay.
It needs both glucose and fructose from the breakdown of sucrose in food and soft drinks to produce plaque and lactic acid.
Tooth decay occurs if the food contains sugars or starches, e.g. sweets, biscuits, cakes and soft drinks containing sucrose.
Avoid these foods between meals.
Cleaning of the teeth immediately after meals will lessen decay, especially if the last food eaten is fruit or raw vegetable.
3. Plaque bacteria change carbohydrates, e.g. sugar in food and drink, left on teeth to acid.
This acid demineralizes teeth like the action of acid on an eggshell.
Some foods already contain acid so dentists recommend avoiding sweet sticky foods and acidic drinks particularly between meals to
reduce the frequency of acidic episodes.
Chewing pressure forces food to be trapped between teeth and inside the pits and fissures where most cavities develop.
Expansive fillings or fissure sealants prevent food being trapped and greatly reduce decay.
Some sugarless foods, e.g. like nuts, are hard to displace and act as temporary sealants and displace previously trapped food to
reduce acid demineralization.
Chewing also provides better access for saliva and fluoride to neutralize acid and remineralize demineralized tooth.
Tooth decay is the most common disease particularly in teenagers, even with fluoridation.
Though most food is left trapped between teeth after every meal or snack, more than 80% of cavities develop inside pits and fissures
in grooves on chewing surfaces.
Most cavities occur between the age of 12 and 21.
Tooth caries disease has an economic impact, comparable with that of heart disease and diabetes.
2. Another way to reduce dental decay is to drink tap water containing sodium fluorides and to use fluoridated toothpaste.
The enamel in teeth is mostly calcium hydroxyl apatite, Ca5(PO4)3OH, usually written as Ca10(PO4)6(OH)2, that can be converted by
fluorine to Ca10(PO4)F2 that is an even tougher enamel.
Fluoride in water supplies dosed at 1 ppm = 1 mg fluoride per litre is a level which is harmless to humans and may cause a 12.5%
decrease in dental caries.
However, in some individuals, sodium fluoride it may cause long-term problems of dental fluorosis and skeletal fluorosis leading to
brittle teeth and bones in old age.
Small amounts of sodium fluoride, NaF help prevent tooth decay, but high levels may harm your health.
In children whose teeth are forming, excessive fluoride levels may cause dental fluorosis with visible changes in the teeth.
In adults, high fluoride over a long time may lead to skeletal fluorosis with denser bones, joint pain, and limited joint movement, but this
is rare.
Solid sodium silicofluoride or fluorosilicic acid is usually added.
Other sources of fluorine are tea, spinach, bone meal, and fish protein.
Fluoridated toothpaste may contain the active ingredient 0.76% W/W sodium monofluorophosphate or 0.22% W/W sodium fluoride,
and micro particles of calcium as an abrasive and polishing agent, with Mohs' scale below 5.5.
Modern toothpaste contains no sugars.
The solid phase, polishing agent, is suspended in polyalcohols, e.g. aqueous glycerol or sorbitol or propylene glycol, and a suspending
agent, sodium carboxy methylcellulose.
A toothpaste is designed to remove food residue, plaque, and calculus (tartar, calcium phosphate,
Ca3(PO4)2.2H2O).
Calculus is calcified plaque.
The "GC Tooth Mousse Plus" used for topical application of sodium fluoride and calcium phosphate to teeth contains
0.2% W / W (900 ppm) sodium fluoride.
Ca5(PO4)3 (s) + H+ (aq) --> Ca5(PO4)3+ (aq) + H2O (l)
tooth apatite + organic acid --> tooth decay + water
Ca5(PO4)3+ (aq) + F- (aq) --> Ca5(PO4)3F (s)
calcium phosphate ion + fluoride toothpaste --> hard calcium fluorophosphate

9.226.1 Teeth and toothpaste
1. Examine your diet and teeth cleaning habits and decide whether they lessen the chance of tooth decay.
Examine a toothpaste packet and note the contents.

2. Look at your teeth in a mirror and note the four different kinds.
2.1 The front teeth, incisors, are for cutting food.
2.2 The "eye teeth" or canines are for tearing food.
Dogs have big tearing teeth.
2.3 The premolars are crushing teeth.
2.4 The back teeth or molars, are for grinding.
Cattle have big grinding teeth.
Biting teeth, incisors, move up and down to bite in a cutting action.
Bite an apple and examine the bite marks.
To use tearing teeth, canines, bite into the food and pull back on it, like a dog.
Chewing teeth, premolars and molars, move from side to side to grind food into little pieces.

3. Compare the teeth of a child, 5 to 7 years of age with the teeth of an adult or use images from the internet.
Humans have two sets of teeth in their lifetime.
The first teeth, milk teeth, consist of four incisors, two canines, two premolars and one molar.
The second teeth, permanent teeth, consist of four incisors, two canines, two pre-molars and three molars.

4. Compare the molars of a 10 years old child with the molars of a person 17 to 25 years, or older.
The older person usually has the extra third molar each side of the jaw called the "wisdom tooth".
However, sometimes the wisdom teeth do not erupt properly and remain imbedded in the jawbone, requiring serious dental surgery.

5. Examine the jawbone of a rat or a rabbit or use images from the internet.
Compare the arrangement of their teeth with human adult teeth.

9.227 Small intestine, model with dialysis tubing
You may have to seek approval to work with human saliva because it can spread disease.
Instead of using human saliva, use salivary amylase from a laboratory supply company.
Before cutting dialysis tubing, rub the end of the tubing between thumb and finger under water.
When the surfaces of the tube begin to slide, select the length needed and blow into the wet end.
Hold an end of the dialysis tubing under water until it is soft.
Tie a knot in it and pull the tubing so that the knot is tight.
Hold the other end of the tubing under water until it is soft.
Rub your fingers back and forth on that end to open it.
Cut three lengths of tubing, 10 cm long.
1. Pour starch solution into the first piece of tubing to a depth of cm, then rest it in a beaker.
2. Pour the same volume of starch solution into the second piece of tubing and add 2 mL of dilute saliva solution.
Shake the piece of tubing to mix the starch and saliva, then rest it in a beaker.
3. Add glucose solution to a depth of 5 cm in the third piece of tubing, then rest it in a beaker.
Add water at 37oC to each beaker so that the water level in each beaker is the same as the level of the solutions in the tubing.
Leave the beakers until the next day.
Dialysis tubing and sausage skin are similar to the membrane lining the small intestine.

9.228 Body Mass Index (BMI)
BMI is a ratio calculated from weight in kilograms divided by (height in metres)2.
BMI provides an indicator of body fitness and can be used to screen for weight categories that may lead to health problems.
BMI categories: BMI 30 (obese) BMI 25-29.9 (overweight) BMI 18.5-24.9 (normal) BMI < 18.5 (underweight).
BMI obese students may have a higher risk of heart-related disease, but BMI overweight students may have better survival value and
fewer heart problems than BMI normal or underweight students.
In some countries, fashion models with BMI < 18.5 are not allowed to walk the catwalk in fashion parades because some very thin
models allegedly died of over-dieting.
Calculate your BMI.
In Australia, about 70% of men and 56% of women are overweight or obese. The average BMI in 2011-2012 was men 27.9 kg / m2
and women 27.2 kg / m2.
A new alternative to BMI is BAI (Body Adiposity Index), that uses the correlation of hip circumference and height with percentage
body fat as a measure of obesity.

9.229 Children with diarrhoea, ORS special drink
See 6.14: Shakir strip (Test for malnourished child)
1. Diarrhoea means frequent watery stools.
Often children with diarrhoea also have vomited and have a swollen belly with cramps.
The stools smell different from normal stools, faeces.
Children die of diarrhoea usually because their bodies lose too much water, dehydration.
The signs of dehydration are as follows:
1.1 almost no urine that is dark yellow,
1.2 dry mouth,
1.3 sunken tearless eyes,
1.4 sunken soft spot (fontanelle) on top of a baby's head,
1.5 skin loses its stretching.
If you lift up the skin and you can still see the fold after you let go, the child is dehydrated.
2. In many places, diarrhoea is the most common cause of death in small children, and is specially frequent in babies between six
months and two years.
It is more common and dangerous in children who are malnourished.
Bottle-fed babies have diarrhoea more often than breast-fed babies.
Diarrhoea can be prevented by breast-feeding babies for as long as possible, good nutrition and cleanliness.
Take the child with diarrhoea to a doctor if the child shows any signs of dehydration, cannot drink or will not drink, makes no urine for
six hours, has diarrhoea too often and cannot drink one glass of water per stool, has blood in the stool, and if diarrhoea lasts more
than two days.
3. Children with diarrhoea must be given food, if they can take it.
Replace the water lost through diarrhoea and vomiting with coconut water or the ORS drink (oral rehydration salts drink), sometimes
called the "special drink".
To make the ORS special drink, dissolve 4 teaspoons of sugar (sucrose) and half a level teaspoon of salt in 1 litre of clean water.
Taste the drink before giving it to a sick child.
It should taste no more salty then the tears in the eye.
Too much salt can be dangerous for a sick child.
Start giving the sick child the ORS special drink, or coconut water, when diarrhoea begins.
The child should drink a glass of special drink each time a stool is passed.
If the child vomits up the drink, keep giving more because some will stay in the stomach.
Give the drink in sips every two or three minutes.
If the child does not want to drink, gently insist that the child try to drink something.
Keep giving the drink, day and night until the child urinates normally.
If the child will not drink and you are concerned about dehydration, seek professional medical advice.
The sugar and salt for the ORS special drink is often available in special packets from the pharmacy or health workers in rural areas.
4. O.R.S. (oral rehydration salts), product used to treat diarrhoea and traveller's gastroenteritis in children and adults, contains a
balanced mix of glucose and salts in water.
The reconstituted solution may be stored in the refrigerator for up to 24 hours, otherwise unused solution should be discarded within one hour.
It recommends 1/2 to 2 sachets in 200 mL of fresh drinking water every 3-4 hours for children and 1-12 sachets after every loose
bowel motion for adults over 12 years.

9.230 Bones and skeleton
See diagram 9.230: Skeleton 1 | See diagram 9.231: Skeleton 2
Bone, calcium hydroxyapatite, Ca10(PO4)6(OH)2, + other ions
1. Examine different animal bones and describe their function, e.g. skull bones, backbones, ribs, shoulder bones, hip bones, arm and
leg bones.
The skull protects the brain.
The jaws move the mouth and the teeth are attached to them.
The vertebrae join to form the spine that connects all the bones.
The shoulder and hip bones connect arms and legs to the spine.
The ribs protect the lungs and heart, and allow the chest to get bigger and smaller.
The arm and leg bones allow movement of arms and legs.
Compare a young bone with an old bone.
The young bone is softer and contains haemopoietic tissue that makes blood.
Old bones are strong and may contain fat.
Broken bones are very dangerous for old people because fat may leak out of the broken bone into the bloodstream and cause blockages.

2. A joint is where a bone joins another bone.
See diagram 21.1.3.4: Arm joint
2.1 Hinge joints allow forwards and backwards movement, like a door, e.g. the knee joint.
2.2 Ball joints allow movement in a circle, swinging the arm in a circle, e.g. the shoulder joint.
2.3 Pivot joints allow turning movement, turning the handle of a door, e.g. the forearm.
2.4 Fixed joints do not move, but allow plates of bones to grow, e.g. the bones in the skull.
A foetus and a very young baby have joints in the skull, fontanelles, where the bones have not joined.
These joints allow the skull to expand and grow.
When putting a baby down to sleep always have one hand under the head.
Experiments
1. Examine the different kinds of joints in the body: jaw (hinge), elbow (hinge and pivot), finger (hinge), foot (pivot), upper leg (ball),
backbone (pivot), neck (pivot and hinge).

9.231 Measure your height
1. Stand against the wall with feet together, heels against the wall, back against the wall, hands to the sides, head against the wall,
looking straight out.
Ask another student to measure your height.
Use a ruler, book, pencil or chalk, metre stick or tape measure on the head and at right angles to wall.
Push down bushy hair.
Push the back of the head, shoulders, buttocks and heels against the back of the wall.
Use a metre stick or tape measure with zero on the floor or draw a metric scale or attach a metre stick to wall.

2. Measure the heights of all the students in the class.
Mark heights on the wall with a ball point pen or felt pen.
Measure the heights in centimetres and to a nearest millimetre.
Draw a bar graph of heights to the nearest centimetre.
Record heights and dates in a book on the same day every month.

3. The formula for the height of a full grown adult is as follows: height of adult = average of heights of the two parents (+ 7 cm for men)
and (-7 cm for women).
Calculate your expected height as a full grown adult.

9.232 Muscles, use the muscles
See diagram 9.232: Arm muscles
The three kinds of muscle are as follows:
1. Striated muscle, voluntary muscle, attached to bones in the skeleton
2. Smooth muscle, involuntary muscle, in the walls of the stomach, intestines, bladder and blood vessels
3. Cardiac muscle in the wall of the heart
Muscles work only by contraction, i.e. pulling, so for each muscle that bends a limb, another muscle can straighten it again.
Pairs of muscles with opposite action are called antagonists.
For example, the biceps muscle bends the arm at the elbow and the triceps muscle straightens the arm again.
When a muscle contracts it changes in shape but it does not change in volume.
Grab the upper arm with the left hand with the fingers above the arm and thumb below the arm.
While bending and straightening the right arm, feel the muscles contract and expand.

Experiments
1. Close one hand, form a fist, then bend that arm at the elbow, while feeling the muscle of the upper arm with the other hand.
Feel the change in shape of the muscle as the arm is raised and lowered.
As the arm is raised, the muscle becomes short, fat and hard.

2. Lie on the ground on the back and feel the stomach while raising the legs.

3. Try different movements, e.g. walking on the toes, lifting objects, press-ups, standing on hands, knee-bends.
Feel and see the muscles and joints working.

4. Keep a straight back then bend the knees until the hands touch the floor.
Note where you feel pain.
Feel behind the legs above the knees, when you bend, when you straighten.
Feel the muscle that straightens the legs.

9.233 Fingerprints
See diagram 9.233: Fingerprints
Fingerprints can be developed by using ninhydrin
See: Tests for ammonia or amino acids or proteins with ninhydrin: 10.2.2.5a
Describe fingerprints using a stamp pad, magnifiers soap and water.
1. If you do not have a stamp you can use carbon paper or make carbon paper from aluminium foil.
Use a piece of aluminium foil or silver paper.
Hold it in a candle flame so that the lower side becomes covered evenly with a layer of carbon.
Test the carbon foil you have made.
It is like carbon paper.
You can use it to make fingerprints.

2. Look at the skin on your finger tips.
There are lines on them.
Look for lines with the shapes in the diagram: whorl, loop, arch.
Make a print of your thumb use a stamp pad or pour some ink onto absorbent.
Press your thumb onto the inky paper.
Wet it all over with the ink.
Then press your thumb onto a sheet of clean white paper.

3. Look carefully at the thumb print.
Look for arches, whorls, and loops.
Use a magnifying glass to examine the lines in the skin of the fingertips.
Make a print of the thumb with a stamp pad or ink poured on absorbent paper.
Also, hold a piece of aluminium foil in a candle flame so that it becomes covered with a layer of carbon and press your thumb on the foil.
Press the thumb on a sheet of clean white paper.
Use a magnifying glass to examine the thumbprint.
Look for arches, whorls, and loops.

Examine the thumbprints of others.
3.1 About 5% of fingerprint patterns are arches where the ridges run from one side to the other of the pattern and make no backward
turn.
Arch patterns usually have no delta, a triangular-shaped pattern where different fingerprint ridges meet.
Plain arches have an even flow of ridges from one side to the other of the pattern, with no significant upthrusts.
The ridges enter on one side of the impression, and flow out the other with a rise or wave in the centre.
Radial arches have ridges that slope towards the thumb.
Ulnar arches have ridges that slope towards the little finger.
Tented arches have an angle, an upthrust near the middle that arrange themselves on both sides of an axis towards which the adjoining
ridges converge and appear to form tents.

3.2 About 60-70 % of fingerprint patterns are loops where ridges enter on either side and touch or cross the line running from the
delta to the core and terminate in the direction of the side where the ridges entered.
Each loop pattern has is one delta and one core and a ridge count.
Radial loops run in the direction of the thumb and usually occur on the index finger.
Ulnar loops run in the direction of the little finger.

3.3 About 25-35 % of fingerprint patterns are whorls where ridges make a turn through at circuit.
Any fingerprint pattern with two or more deltas are a whorl pattern.
Plain whorls have ridges making a complete circuit with two deltas.
If an imaginary line is drawn between the deltas, at least one re-curving ridge within the inner pattern area is cut or touched.
Central pocket loop whorls have one re-curving ridge with two deltas.
If an imaginary line is drawn between the deltas, no re-curving ridge within the pattern area is cut or touched.
Central pocket loop whorl have ridges making one complete circuit, spiral, oval, or circular.
Double loop whorls have two separate loop formations of ridges, two deltas and ridges that make a complete circuit.
If an imaginary line is drawn between the deltas, at least one re-curving ridge within the inner pattern area is cut or touched.
Accidental whorls have two types of patterns with two or more deltas.

4. None of the thumb prints of other children are the same.
No two thumbprints are the same, not even in identical twins, so police use fingerprints to identify people.
If a robber breaks into a house he leaves invisible fingerprints on anything he touches, e.g. door handle.
The police can put a special powder on the door handle and record the fingerprints.
Later the police can catch a man who could be the robber.
The police put ink on the man's fingers and take the fingerprints.
Then they compare the man's fingerprints with those they took off the door.
If the fingerprints match then the police have caught the robber.

5. Draw the outline of your thumb.
Draw in the whorls, loops and arches.
Draw the fingerprints of your other fingers.
They do not have the same pattern as the thumb.
6. "Fingerprint Game" Each child in the group makes two sets of fingerprints.
The teacher takes one set, then gives back one print of the "robber".
Now compare the "robber's" fingerprint to all the fingerprints.
Who is the "robber"?

9.234 Finger lengths
See diagram 9.233: Finger lengths
1. Measure the lengths of your fingers as shown in the diagram.
2. Calculate the ratio: length of middle finger/length of little finger.
3. Is this ratio the same for all children?
Is it the same for boys or girls?

9.235 Measure your weight
Use a bathroom scale or sling scale to record the weight in kilograms of each student on the same day each month, e.g. 15th day of the month.
Record the weights on a wall chart.
At the end of the year each student draws a graph of the recorded weights.
Calculate the average weight of the students each month.
Discuss how to measure the weight of your head.

9.236 Shakir strip and malnourished child
See 6.14 Shakir strip (Test for malnourished child)
Learn to use the Shakir Strip.
When babies are about one year old, they have much fat under the skin of their arms.
By the time they are five years old the fat is replaced by muscle, so the circumference of the upper arm is almost the same between
the ages of one and five.
To detect malnourished children, measure around the middle of the upper arm of children between the ages of one to five years with a
specially marked tape, the Shakir strip.
It is made of unstretchable material one centimetre wide and forty centimetres long.
The colours along the length of the strip in sequence are grey 6 cm, red 6.5 cm, yellow 1 cm, green 6.5 cm and a length of grey to
make up a total of 40 cm.
Measure from the grey zone end.
If the circumference of the upper arm > 13.5 cm, green zone, the child is healthy and not malnourished.
If the circumference of the upper arm is between 12.5 and 13.5 cm, yellow zone, the child is probably malnourished.
If the circumference of the upper arm is < 12.5 cm, red zone, the child is certainly malnourished.
Make a Shakir strip and measure the circumference of the upper arms of children before their fifth birthday.

9.237 Hair
1. List the places where hair grows on the body.
List the places where hair does not grow on the body, e.g. palms of the hands, soles of the feet.

2. Find the longest hair of all the people in the class.
Note whether the longer hairs come from males or females.

3. Pull out a hair from the head with a quick pull and put it on the sheet of white paper.
Note the part of the hair from above the skin, which is dead, and the hair root from below the skin.
At the end of the root is the bulb where cells divide to increase the length of the hair.

4. Use a magnifying glass to examine the skin on the back of the hand and on the palm of the hand.
Note the hair follicles where the hairs come out of the skin.

9.239 Immunity, vaccinations
1.1. Antigens are usually foreign proteins that stimulate an immunity reaction.
1.2. Antibodies are the globular proteins (immunoglobulins) produced to counteract the effect of specific antigens in an
antibody-antigen reaction.
1.2.1 Bacteria may produce toxins that may be counteracted by specific antitoxins.
2. Immunity is the ability to resist infection, diseases and unwanted biological invasion by the action of lymphocytes, phagocytes and
antibodies in an immune reaction.
2.1.1 The T lymphocytes attract phagocytes, cause inflammation, control B lymphocytes, and contain the memory of past infection to
allow long-term immunity.
2.1.2 The B lymphocytes in the lymphatic tissue and lymph nodes produce plasma cells that secrete antibodies.
2.2 Phagocytes, i.e. leucocytes and monocytes, engulf bacteria.
2.3 Antibodies can:
2.3.1 clump, pierce, coat and inactivate bacteria,
2.3.2 neutralize toxins,
2.3.3 as the protein interferon, prevent viruses multiplying.
3. Natural immunity is the immunity we are born with without any previous contact with disease.
3.1 Acquired (passive) immunity is additional short term immunity from:
3.1.1 Antibodies that cross the placenta and antibodies from colostrum before breast milk secretion and from breast milk.
3.1.2 Injection of antibodies in an antiserum, e.g. snake poison antibodies in horse antiserum
3.1.3 Injection of immunoglobulins into a sick person from another person who has been infected by the same disease,
e.g. chickenpox, hepatitis C.
4. Active immunity is the long lasting immunity from a host producing antibodies in response to:
4.1 Natural infection
The "hygiene hypothesis" is that childhood exposure to pathogens primes the immune system and that children reared in the very clean
environments of affluent families do not develop a mature immune system.
4.2 Injection of a non-potent form of antigen (attenuated antigen) in a vaccine produces a slow primary immune response.
This response leads to a fast secondary immune response to later infection by this antigen because of the new memory stored in the
T lymphocytes.
Table 19.239 Vaccinations given in Australia
Disease Vaccine
1. Diphtheria, Tetanus, Pertussis, Hepatitis B DTPa-hepB
2. Haemophilus Influenzae type B Hib (PRP-OMP) or Hib (PRP-OMP)-hepB
3. Poliomyelitis OPV
4. Measles, Mumps, Rubella MMR
5. Diphtheria, Tetanus Td
6. Pneumococcal disease Pneumococcal vaccine
7. Influenza Influenza vaccine
Make list of the vaccinations given to persons in your class or family.

9.240 Forensic science topics
See: Forensics, (Commercial)
Blood groups
Detect a forgery: 10.2.2.4
DNA fingerprinting
Fingerprints: 9.233
Forensic entomology
Hair analysis
Drowning case - using osmosis and diffusion
Post mortem changes
Time of death

12.3.01 Blood pressure
See: Circulation, (Commercial)
See: Physiology, (Commercial)
See: Sphygmomanometer, blood pressure meter, (Commercial)
Blood pressure is measured with a sphygmomanometer, by wrapping an inflatable pressure cuff around the
upper arm of a relaxed and sitting person.
So the cuff is at the approximate level of the heart to eliminate any problem with hydrostatic pressure.
It is recorded as two numbers, e.g. 130 / 85.
The larger number indicates the systolic blood pressure, the pressure in the arteries as the heart pumps out blood during each beat,
i.e. the pressure when the heart pumps blood into the circulation.
The lower number indicates the diastolic blood pressure, the pressure as the heart relaxes before the next beat, and takes in blood.
Human blood pressure is measured in millimetres of mercury, mmHg.
The normal blood pressure for adults over 18 years is less than 130 mmHg systolic and 85 mmHg diastolic.
he normal blood pressure for adults over 65 years is less than 140 mmHg systolic and 90 mmHg diastolic.
Persons with blood pressure higher than these levels suffer from hypertension and may be more likely to have strokes, heart attacks and
kidney failure.
Hypertension can be treated without medication by following a nutritious diet, restricting sodium chloride in food, limiting alcohol
consumption, avoiding stress, and regular exercise to make you "out of breath".
Normal range of values of blood pressure of resting persons, in mm Hg: 3 months 90/50, 10 years 90-125/60, adult 95/60 to 140/90.

12.3.02 Water in blood
The concentration in body fluids is about 280 to 296 millimols per kilogram, less is detected by thirst sensors and more is eliminated by
the kidneys in urine and in faeces.
An adult should drink about 1 litre of water per day in a temperate climate.
Excess intake of water e.g. "8 glasses of water per day" is not needed and real excess intake can cause fatal swelling of the brain.
Alcohol acts as a diuretic to make the drinker more thirsty and drink more alcoholic drinks.

12.3.03 Hydrocortisone, C21H30O5, cortisol, glucocorticoid, corticosteroid, secreted by adrenal cortex, promotes protein catabolism,
gluconeogenesis, capillary wall stability, renal excretion of calcium, suppresses immune and inflammatory responses,
synthetic hydrocortisone used to treat inflammation, allergy, collagen diseases, asthma, shock.

12.3.04 Tattoo removal
Tattoo removers use ultra-short pulses (one trillionth of a second in length) to hit the melanin with a great pressure, the melanin shatters
into tiny dust-like particles.
The particles are so small, they are more readily absorbed and eliminated by the body.
This can mean better clearance of the melanin and less treatments overall.