3- Keeping Internal Conditoins Constant

Question 1

What waste products have to be removed from the body and how?

Answer 1

Carbon dioxide, removed during breathing via the lungs

Urea, produced by the liver from the breakdown of amino acids. Removed by the kidneys then (temporarily) the bladder in urine

Question 2

What could happen if water or ion content is wrong in the body?

Answer 2

Too much or too little water may move into or out of cells, which could damage or destroy them

Question 3

What is the role of the bodies two kidneys?

Answer 3

They filter the blood, excreting substances you do not want and keeping substances the body needs

Question 4

How does a healthy kidney produce urine?

Answer 4

Filtering the blood
Re absorbing all the sugar, dissolved ions and water needed
Releasing urea, excess ions and water in urine

Question 5

What does a dialysis machine do?

Answer 5

Keeps people with kidney failure alive by carrying out the same job as a functioning kidney (the blood flows through partially permeable membrane)

Question 6

What is the disadvantage to dialysis treatment?

Answer 6

Regular trips to the hospital

Expensive

Question 7

What can happen in a kidney transplant if the tissue is not a good match?
How can the recipient of the kidney help stop this after it happens?

Answer 7

The bodies antibodies may attack the kidneys antigens because they recognise them as ‘foreign’

Take drugs which suppress the immune response (immunosuppressants)

Question 8

What are the disadvantages to kidney transplants?

Answer 8

The treatment suppresses the patients immune system which leaves them vulnerable

Question 9

Where is body temperature monitored and controlled and how?

Answer 9

The thermoregulatory centre in the brain, it has receptors which detect the temperature of the blood

Skin temperature sensors also send impulses to the brain

Question 10

What happens in the body if the temperature core rises?

Answer 10

Blood vessels near the skins surface dilate allowing more blood flow -
Energy is transferred by radiation, cooling the skin
Sweat glands produce sweat which, when it evaporates, cools the skin down

Question 11

What happens in the body if the core temperature falls?

Answer 11

Blood vessels near the skins surface constrict blood flow though capillaries, using less energy
We shiver, muscles contract quickly which requires respiration - the energy warms the blood

Question 12

What do doctors need to consider when deciding whether a patient should have dialysis or kidney transplant?

Answer 12

The patients general health
How long the patient has been on dialysis
The total/long term cost
The risks
The availability of kidneys

Question 13

What are the ethical issues surrounding kidney transplants?

Answer 13

Should everyone be automatically registered for a transplant?
Should people be paid to be donors?
Should people be able to jump the transplant queue by paying?

Question 14

What temperature do enzymes need to work at?

Answer 14

37*C. Body temperature

This is why in extreme conditions the body fails to work

Question 15

Why do children become freezing or dehydrated very quickly?

Answer 15

They have a small surface area to volume ratio, meaning they will give off energy very easily and are not large enough to recover the energy

Question 16

What happens to enzymes if the body temperature is too 1)low 2)high?

Answer 16

1) they will work slowly

2) they denature

Question 17

What does the pancreas do?

Answer 17

Monitors and controls the level of glucose in our blood. If there is too much, it produces insulin (a hormone) which causes the glucose to move from the blood into cells.
It also releases glucagon (a hormone)

Question 18

What is homeostasis?

Answer 18

Keeping the conditions of the body within a narrow range

Question 19

What happens to glucose in the liver?

Answer 19

It is converted to glycogen for storage

Question 20

What is type 1 diabetes and how is it controlled?

Answer 20

If too little insulin is produced by the pancreas the blood glucose levels may become very high.
This is controlled by insulin injections (causing the blood glucose level to fall) and careful attention to the patients healthy active lifestyle

Question 21

What type of insulin is usually used as treatment?

Answer 21

Human insulin produced by genetically engineered bacteria

Question 22

Things to know about diabetics?

Answer 22

Has to inject before meals everyday (having to match their insulin intake with diet and exercise
Some use pumps instead of injections

Question 23

What methods are doctors experimenting with for type 1 diabetes treatment?

Answer 23

Pancreas transplant
Transplanting pancreas cells
Using embryonic stem cells
Using adult stem cells genetically engineering pancreas cells