Animal Nutrition II

Question 1

Where does both digestion and absorption take place?

Answer 1

Ileum

Question 2

State 6 adaptations of the small intestine

Answer 2

1) very long and folded

2) presence of villi and microvilli

3) one- cell thick epithelium

4) intestinal wall and villi richly supplied with blood vessels to transport sugar and amino acids away from small intestine.

5) villi contains lacteals that transport fats away from the small intestine

6) smooth muscles that constantly relax and contract in a wave- like pattern (peristalsis)

Question 3

Why is there a presence of villi and microvilli in the small intestine?

Answer 3

These protrusion in the intestinal wall further increase surface area to volume ratio

Question 4

Why is the intestinal wall and villi richly supplied with blood vessels?

Answer 4

This is to maintain a concentration gradient to facilitate diffusion.

Question 5

Why does villi contain lacteal?

Answer 5

It transports fats away from the small intestine. It maintains a concentration gradient to facilitate diffusion as food is transported away quickly and effectively.

Question 6

Why does the smooth muscles constantly relax and contract?

Answer 6

This is to bring food into close contact with the intestinal wall.

Question 7

Is the concentration inside the villi high or low?

Answer 7

low

Question 8

What are the substance transported in villi:
blood capillaries–>

Lacteals–>

Answer 8

Blood capillaries–> glucose and amino acids

Lacteals–> Glycerol and fatty acids

Question 9

Where do fatty acids and glycerol diffuse into?

Answer 9

Epithelium of the villus and recombines into fat droplets

Question 10

will cellulose be digested?

Answer 10

No. They will not be digested at all. They will be egested as faeces.

Question 11

What are simple sugars converted into at the liver?

Answer 11

glycogen (insoluble form of storage)

Question 12

How is glycogen converted back to glucose when the body requires more energy?

Answer 12

It is converted back via the hormone (adrenaline) or glucagon (produced by pancreas).

Glycogen —–(adrenaline/ glucagon)—–> glucose

Question 13

What is the function of amino acids?

Answer 13

They are essential substances to form new protoplasm, for growth, and repair of tissues and also to form enzymes and hormones.

Question 14

What is the process called when excess amino acids are broken down in the liver?

Answer 14

Deamination.

Question 15

Does insulin level increase when glucose concentration decrease?

Answer 15

No. When glucose concentration decrease, glucagon increases, insulin decreases.

Question 16

Increase in glucose concentration refers to increase insulin level. Is this true? Explain.

Answer 16

Yes. As there is higher glucose concentration in the blood, the release of more insulin can increase the uptake of glucose by liver. Thus increase glycogen to store more glucose in the liver.

Question 17

State the important functions of the liver. (6)

Answer 17

1) Regulate blood glucose concentration
Excess glucose –> glycogen (insulin) [glucose lvl high]
glycogen –> glucose (glucagon) [glucose lvl low]

2) Metabolism of fats
–> production of bile to emulsify fats

3) Metabolism of proteins
-amino acids undergo deamination to form urea for excretion
- synthesise plasma proteins such as fibrinogen for blood clots

4) Detoxification
- break down/ transform substances like metabolic waste, drugs, alcohol so that they can be excreted out.

Alcohol —– (alcohol dehydrogenase)—> carbon dioxide + water

5) Storage
Liver breaks down haemoglobin and stores the iron released in the process.

6) Heat production
heat produced when liver carries out various chemical functions. This heat is maintained by blood to other parts of the body so as to maintain body temperature.

Question 18

What does it indicate when the faeces are pale and oily. Explain.

Answer 18

This indicates a decrease in bile production. This suggest that emulsification cannot be carried out, hence oil is being excreted out of the body.

Question 19

What are the disadvantages of alcohol towards the liver?

Answer 19

-replace fresh liver tissue with scar tissues (cirrhosis)

Question 20

What are the short term effects of alcohol?

Answer 20

-hard to concentrate
-reaction becomes slower
-confusion
-slurred speech
-mood change
-vomitting
-nausea

Question 21

What are the long term effects of alcohol?

Answer 21

-High blood pressure
-hallucinations
-brain injury
-irregular heartbeat
loss of memory
-liver damage (liver cancer and hepatits)

Question 22

Why does excess acid in stomach cause stomach ulcer?

Answer 22

Peptic ulcers occur when acid in the digestive tract eats away at the inner surface of the stomach or small intestine

Question 23

What are the social effects of consuming alcohol?

Answer 23

1) reduced self-control (impulsive)
2) slow down brain function
3) poor reaction time –> lead to accident (depressant)
4) depression + anxiety (mental health problems)
5) work performance and productivity decreased