Homeostasis

Question 1

Waste products that need to be removed from the body include:

Answer 1

Carbon dioxide from respiration.

Urea from the breakdown of amino acids.

Question 2

If the water or ion content of the body is wrong, what happens?

Answer 2

Too much water moves into or out of the cells and damages them.

Question 3

How do water and ions enter the body?

Answer 3

In what we eat and drink.

Question 4

A healthy kidney produces urine how?

Answer 4

Filtering the blood.
Reabsorbing all the sugar.
Reabsorbing the ions needed in the body.
Reabsorbing as much water as the body needs.
Releasing urea, ions and excess water as urine.

Question 5

How can kidney failure be treated?

Answer 5

By dialysis or kidney transplant.

Question 6

Kidney dialysis has to be carried out at what kind of intervals?

Answer 6

Regular intervals.

Question 7

What happens during dialysis?

Answer 7

A person’s blood flows through partially permeable membranes. Dialysis fluid contains the correct concentration of useful substances ensuring mineral ions and glucose are not lost. Urea passes out of the blood and into the dialysis fluid.

Question 8

What may happen to the transplanted kidney when it is put into a host who needs it?

Answer 8

It may be rejected by the host’s immune system.

Question 9

What happens when a organ is rejected?

Answer 9

The host’s immune system does not recognise the antigens of the cells of the donated organ so produces antibodies to attack the donor cells.

Question 10

How can rejection of an organ be prevented?

Answer 10

A donor with a similar tissue type is used.

The recipient is treated with drugs that suppress the immune system.

Question 11

Sweating helps to do what to the body?

Answer 11

Cool the body.

Question 12

When water is lost through sweating what must happen?

Answer 12

The body must take in more water through food or drink to balance this loss.

Question 13

Body temperature is regulated and controlled by…

Answer 13

…the thermoregulatory centre in the brain.

Question 14

The thermoregulatory centre in the brain detects a change in body temperature how?

Answer 14

Highly sensitive receptors monitor blood temperature flowing through the brain.

Question 15

The thermoregulatory centre detects a change in temperature outside the brain how?

Answer 15

Receptors in the skin send impulses to the thermoregulatory centre, giving information about skin temperature.

Question 16

If core body temperature is too high…

Answer 16

…blood vessels supplying the capillaries in the skin dilate causing greater heat loss and sweat glads release sweat that evaporates on the skin which cools the body.

Question 17

If core body temperature is too low…

Answer 17

…blood vessels constrict, reducing blood flow in the capillaries and muscles may shiver causing more respiration and more heat to be produced.

Question 18

Blood glucose levels are controlled from where?

Answer 18

The pancreas.

Question 19

The pancreas produces what hormone to allow glucose to move from the blood into cells?

Answer 19

Insulin.

Question 20

What hormone is produced when blood glucose levels fall and what does it do?

Answer 20

Glucagon. It causes glycogen to be converted into glucose in the body and be released into the blood.

Question 21

Type 1 diabetes may occur by…

Answer 21

…someone’s pancreas not producing enough insulin causing blood glucose levels to rise too high.

Question 22

Type 1 diabetes can be controlled by…

Answer 22

…careful attention to diet, exercise and injecting insulin.