B12-Homeostasis in action

Question 1

What is the temperature human bodies need to stay at?

Answer 1

37 degrees C

Question 2

Why is it important to keep body temperature constant?

Answer 2

for optimum enzyme function

Question 3

What regulates core body temperature?

Answer 3

thermoregulatory centre in the hypothalamus

Question 4

How do you cool down?

Answer 4

Vasodilation.

Blood vessels supplying blood to the capillaries dilate allowing more blood to flow through. You transfer more energy by radiating heat from your skin to the surface, this causes you to cool down and warms up the air around you

Sweat glands produce more sweat, extra sweat cools body down as the sweat evaporates and transfers energy to the surroundings.

You need to drink more water to balance this change

Question 5

How does your body keep warm?

Answer 5

Vasoconstriction

Question 6

What are the 2 main waste products?

Answer 6

Urea and Carbon dioxide

Question 7

How is carbon dioxide formed and why is it important to get rid of it?

Answer 7

produced from respiration

broken down carbon dioxide produces an acidic solution which would affect enzyme action

Question 8

How is CO2 removed?

Answer 8

diffuses from the cells into your blood down a concentration gradient and diffuses from the blood into the air in the lungs.

Removed when you exhale

Question 9

What is urea?

Answer 9

Nitrogenous waste formed from the breakdown of excess amino acids in the liver

Question 10

How does urea leave the body?

Answer 10

filtered out the blood by the kidney then passed out through the urine

Question 11

What 4 things do kidneys filter?

Answer 11

• glucose
• mineral ions
• urea
• water

Question 12

How much glucose is reabsorbed?

Answer 12

ALLLLLL

Question 13

What is selective reabsorbtion?

Answer 13

the process by which kidneys selectively reabsorb the amount of water and mineral ions

Question 14

What is the system that involved with ADH?

Answer 14

negative feedback

Question 15

What happens when the water content in the blood is too high?

Answer 15

receptors in the brain detect the water content too high and stimulates the pituitary gland to release more ADH which causes the kidneys to reabsorb more water until the water content is back to normal?

Question 16

What happens if the water content in the blood is too low?

Answer 16

receptors in the brain detect that there isn’t enough water content. Stimulates the pituitary gland to release less ADH which means less water is reabsorbed from the kidney.

Question 17

What can cause a kidney to be damaged?

Answer 17

genetic or car accident

Question 18

What is dialysis?

Answer 18

a persons blood flows through a partially permeable membrane and it filters the blood as if a kidney would

lose the bad stuff but equally as important that the useful things like glucose isn’t lost

8 hours to complete

Question 19

How is the loss of glucose and needed mineral ions ensured in dialysis?

Answer 19

the dialysis fluid contains the same concentration of glucose and mineral ions as a healthy person and this ensures there’s no net movement of glucose.

excess mineral ions are removed through diffusion

Contains no urea which ensures as much urea as possible leaves the blood

Question 20

What are the disadvantages of dialysis?

Answer 20

person has to have a very careful diet

have to always be near a hospital

Question 21

What are the disadvantages of kidney transplant?

Answer 21

• eventually will fail and patient has to return to dialysis
• immunosuppressant drugs
• large risk of rejection