Topic 7 [Human Nutrition] 

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> Getting all the right nutrients in correct proportions. 

A Balanced Diet: 

Contains : To meet our . 

Contains To provide the essential that are used to make for or . 

Contains . (Uses of the stated will be listed later) 

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- Children below 12: Require more for

- Teenagers: Require (Carbohydrate) for more energy

- Adults: Balanced diet with

- Pregnant Mother: More (for of the infant), (of ) and () 

**Folic acid should be ingested 3 months before pregnancy for full nutrition.**

- Males: Generally require energy 

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- A condition caused by

There are three different forms of malnutrition: 

1. : Balanced diet but eating too much of everything 

2. : Having too little food 

**People suffering from undernutrition tend to have swollen abdomens. This is because there is a lack of solute (proteins, glucose, etc.) in the blood. When the solute concentration is low, the water potential in blood is too high, so the extra tissue fluids will channel out the blood vessel as the water potential outside is lower. The extra tissue fluids cause the abdomen to be swollen.** 

3. : E.g gaining too much kilojoules from fats, too few from carbohydrates 

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- Losing strengthand finally dying due to the lack of food. 

- Lack of roughage (fibres: from vegetables) in food. 

- Roughages are indigestible and form bulks. 

- Friction between bulks and walls of intestine stimulate the peristalsis (squeezing movement of large intestine to move faeces). 

- Take place in the coronary arteries, which are the main blood vessels delivering nutrients to the heart 

- Caused by eating too many fats which are rich in saturated fatty acids (no double bonds between the C) and cholesterol. 

- Blood vessels having walls of fats 

- Eating too many fats and carbohydrates. 

- Storage of excess fats leads to an increase in body weight. 

- This can cause heart attack and high blood pressure. 

- Lack of vitamin C in diet. 

- Causes bleeding gums. 

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> Rice, potatoes, cereals, etc. 

1. A source of energy 

2. is used in to release energy 

> Saturated (No double bond): Meats, eggs, cheese 

> Unsaturated (w/ double bond): Sunflower seeds, peanuts 

1. A source of energy 

2.

3. Make

> Meats, fish, milk, legumes (soy beans) 

1. (All enzymes are proteins) 

2. (All hormones are protein except sex hormones oestrogen, testosterone, progesterone, androgen) 

3.

4. and

5.

(Roughages) 

> Fruits and vegetables 

1. Provide bulk, to help the walls of the intestine move food and faeces along the gut () 

> Milk and other dairy products 

1. and of strong and

2. For

(Ascorbic Acid) 

> Citrus fruits (Oranges, limes) and raw vegetables 

1. Essential in for

2. Make in skin 

(Calciferol) 

> Butter, egg yolk, made by skin when exposed to sunlight 

1. and of

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: A condition where there is not enough so the tissues , the skin of the person with anaemia is typically paler than usual 

**Haemoglobin (The part of the red blood cell that carries oxygen) is an iron-containing protein**

(Called in adults): A condition where bones become and

: A condition where children did not receive enough of their mother's milk, leading to an impairment of mental and physical development 

: A condition where all body tissues waste away. The child becomes very thin and has wrinkled skin. 

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- The of substances, e.g into the body through the . 

- of food into smaller pieces to the food molecules, using the and the . 

- of large, insoluble molecules into , molecules by actions of . 

- Movement of small food molecules through the wall of the . 

- Movement of food molecules into the where they are . 

- Passing out of food that has not been digested or absorbed as faeces through the anus. 

**The difference between Egestion and Excretion is that Egestion gets rid of undigested stuffs from the alimentary canal. Excretion is the removal of the wastes of metabolism, (e.g sweating & the removal of urine)** 

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1. Mouth 

2. Salivary Glands 

3. Oesophagus 

4. Stomach 

5. Liver 

6. Gall Bladder (Store bile) 

7. Pancreas 

8. Small Intestine 

9. Large Intestine (aka. Colon) 

10. Rectum (Temporary storage of faeces) 

11. Anus 

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- A change in as no enzymes are involved 

- Large pieces of food being broken down by: 

1. Teeth: by chewing () 

2. of the stomach 

Results in: 

> Food that is in size with a for enzymes to react with 

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(Please refer to a diagram from the internet) 

1. (Flat surface): For and

2. (Sharp): For and

3. (Cuboidal): For and

4. (Cuboidal and bigger than premolar): For and

**Upper Set of Teeth contains: 4 incisors, 2 canines, 4 premolars, 6 molars**

**Lower Set of Teeth contains: 4 incisors, 2 canines, 4 premolars, 6 molars** 

**Note that the 3rd pair of molars are also known as wisdom tooth**

(Please refer to a diagram from the internet) 

1. Enamel 

2. Dentin 

3. Pulp 

4. Gum 

5. Cement 

6. Blood vessels 

7. Nerve 

- body tissue, made of **calcium bicarbonate**

- Covers the of the tooth 

- Can be dissolved by produced from the feeding of

- Contains a series of

- Is a

- Contains and

- Nerves

- Blood vessels

- Covers the between and

- Helps to the jaw bone 

- Basically the tooth in place 

(aka. Caries) 

1. Sugar is left on the tooth

2. Bacteria feeds on the sugar, using it for respiration 

3. The product of the respiration are acids 

4. The acid dissolves the enamel and the dentine 

5. Toothache is caused when the decay reaches the dentine, which is where the nerves (that can detect pain) are 

1. Eating foods with

> Eat sweet food only once or twice a day,

2. Brushing teeth with fluoride tootpaste regularly

> Fluoride makes teeth

 > Regular brushing at least

3. Visit the dentist at least twice a year 

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- Mode of digestion involving

- Chemical digestion in the alimentary canal is important because it produces , molecules that can be . 

- Chemical digestion starts at the of food, using the teeth, lips, and tongue 

- The food is mixed with saliva to form the , which is basically just a ball of food

- The is a mixture of (To dissolve food and allow us to taste), (To bind chewed food together to form a , and to it so it can slide down the oesophagus easily), and (To digest into ) 

- The wall of the oesophagus contains

**The contracting and relaxing of the smooth muscles are an involuntary action, which means you don't consciously think about it.** 

**The two types of smooth muscles are called the circular muscles and the longitudinal muscles.** 

- The smooth muscles and to form the movement of peristalsis 

- along the oesophagus 

- The entrance to the stomach contains a muscle called the

- The to let the pass into the

**The sphincter is the muscle that prevents acid reflux.** 

- Muscles in the stomach and to and the food with and , forming a mixture called

- The stomach contains: 

1. Enzymes and

>

> is typically on produced by for

**Clotting of milk is important as it stops the milk from passing through the alimentary canal too quickly. By slowing the movement of milk, more nutrients get absorbed. 

2.

- The acid kills in the food 

- It also provides the for

- The pancreas is just

- It synthesises and secretes into the (The beginning of the small intestine) 

- Pancreatic juice contains

1. - To breakdown into (Which can later be broken down into glucose) 

2. - To breakdown into

3. - To breakdown into and

**Both pepsin and trypsin are types of protease.** 

- : A yellowish-green liquid, made in the and the

- The functions of bile include and

- is the of into a in order to the for the action of in

- (in this context)of the of food and gastric juices from the to provide a for in the

- The small intestine is about with a

- The first part that is to the is called the

- The last part that is to the is called the ileum 

- The small intestine is the first place absorption of nutrients occur 

- Food entering from the stomach into the small intestine is mixed with (Containing amylase, trypsin, and lipase) and (To emulsify fats and to neutralise the stomach acid) 

- The inner walls of the small intestine is covered with millions of tiny projections called

**The plural of villi is villus.** 

- The (Basically a wall of cells, defined as the thin tissue lining the alimentary canal) of each is covered by , which the for of digested food 

- All the digested food molecules are now small enough to pass through the

- Cells covering the villi

 breaks down into

breaks down into and

breaks down into and

breaks down into

breaks down into and

(Please refer to a diagram from the internet) 

> 

Contains thousands of to the for

>

of and

>

Absorption of and

- : The blood vessel that transports food from the small intestine to the liver 

- To make containing salts to

- (Transport of nutrients from blood to tissue) of digested food (glucose) 

- , which is the breakdown of

- : Movement of of the body where they are used

, which is used in respiration to provide energy. Some are converted to for . 

, which are used to build (e.g enzymes, antibodies) 

, which are used to build , which are . They are also an important source of energy in . 

- and are from the undigested food in the colon 

- The colon than the small intestine 

- Temporary storage for /

- Faeces s a mixture of , , and from the alimentary canal 

- The process of is the passing out of at intervals through the

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- is the watery faeces 

- It is caused by or food or water 

The lining of the small intestine is interrupted by (Microorganisms that cause harm or diseases in the human body) 

This causes the small intestine to be to absorb fluid from the food 

 Too much fluid is secreted into the colon 

Undigested food moves through the colon too quickly, leaving insufficient time to reabsorb water 

Diarrhoea can result in

: 

- : Drinking plenty of (water with salts) dissolves in it to the body 

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- Caused by the Vibrio cholerae 

-The bacterium exists inside food or drinks that are by

: 

Vibrio cholera: Releases which the intestinal lining 

Leads to the into the small intestine 

The of the gut, drawing water from surrounding tissues and blood via osmosis 

Causes , , and from blood 

: 

-

- Restoration of the lost by into the bloodstream 

- Use of an to kill the bacteria 

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Leave a vote and comment if this helped you! Disclaimer: I cannot guarantee all the information is correct. I am NOT a professional teacher. 

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