3A- Homeostasis And The Kidneys

Question 1

Which six things need to be controlled for homeostasis?

Answer 1

Temperature of the body
Water content 
Carbon dioxide levels
Blood sugar
Ion content of the body
Urea content

Question 2

Define homeostasis

Answer 2

Functions of the body that must be controlled to maintain a constant internal enviroment

Question 3

How does the body respond to being too hot?

Answer 3

Hairs lie flat on the skin
Sweat is produced (Hair erector muscle relaxes)
Blood vessels move so more blood flows closer to the surface of the skin (Vasodilation)

Question 4

How does the body respond to being too cold?

Answer 4

Hairs stand up to trap an insulating layer of air (Hair erector muscle contracts)
Muscles respire automatically and heat is made as a product (Shiver)
Blood vessels at the surface of the skin are thinner to keep the blood inside the body (Vasoconstriction)

Question 5

Kidneys three main roles

Answer 5

Removal of urea from the blood

Adjustment of water and ions in the blood

Question 6

Why is urea produced by the body

Answer 6

The liver produces urea as a waste product from excess protein being made into fats and carbohydrates

Question 7

How is sweat proportionate with urine

Answer 7

If you don’t sweat, more, less concentrated urine is produced and if you do sweat less more concentrated urine is produced.

Question 8

What do sports drinks do to help with homeostasis?

Answer 8

Water and ions replace those lost in sweat and sugar replaces the sugar lost in respiration in the muscles

Question 9

What is filtered and reabsorbed by the nephrons in the kidney

Answer 9

Water, Urea, Ions and Sugars are squeezed out of the blood.

All sugar is reabsorbed, sufficient ions and water is reabsorbed through active transport.

Question 10

Dialysis machines replace the purpose of the:

Answer 10

Kidneys

Question 11

Transplanted kidneys may be attacked by the body, which precaution is took to prevent this?

Answer 11

A donor with a similar tissue type is chosen

Drugs are administered to suppress the immune system

Question 12

Blood sugar level is controlled by

Answer 12

Insulin and glucagon

Question 13

When the blood glucose level is too high, what is secreted by the pancreas?

Answer 13

Insulin

Question 14

If the blood sugar level is too low what is added?

Answer 14

Glucagon

Question 15

Type 1 diabetes is caused by

Answer 15

A lack of insulin

Question 16

Define Vasodilation

Answer 16

Blood vessels at the surface of the skin becoming wider so more heat is lost

Question 17

Define vasoconstriction

Answer 17

Blood vessels at the surface of the skin becoming thinner so less heat is lost through the skin