Kidneys

Question 1

when is ADH released

Answer 1

when osmoreceptors in the hypothalamus detects the body is dehydrated it stimulates the pituitary glands to secrete ADH

Question 2

what does ADH do? what does this do to urine?

Answer 2

allows makes walls of the collecting duct more permeable to water. more water can pass back into the blood from the collecting duct. this makes urine more concentrated.

Question 3

why is a constant body temperature important

Answer 3

so that enzymes function properly

Question 4

negative feedback

Answer 4

a response to bring about the opposite effect of a stimulus eg too much water, too hot, too much glucose in blood

Question 5

Example of a negative feedback ‘closed loop’

Answer 5

ADH is released when the body is dehydrated. when the body’s water concentration returns to normal ADH stops being released and the body reabsorbs less water.

Question 6

advantages of being homeothermic

Answer 6

chemical reactions can happen at a predictable rate