Endocrine system

Question 1

What are hormones?

Answer 1

Chemical molecules released directly into the blood for homeostasis.

Question 2

Where are hormones secreted from?

Answer 2

Glands.

Question 3

What does the pituitary gland do?

Answer 3

This produces hormones that act on glands to release hormones - ‘the master gland’.

Question 4

What do the ovaries do?

Answer 4

These produce oestrogen for the menstrual cycle.

Question 5

What do the testes do?

Answer 5

Produce testosterone for puberty and sperm production.

Question 6

What does the pancreas do?

Answer 6

Produces insulin and regulates blood glucose levels.

Question 7

What does the thyroid do?

Answer 7

Produces thyroxine which is involved in regulating the rate of metabolism, heart rate and temperature.

Question 8

What does the adrenal gland do?

Answer 8

Releases adrenaline.

Question 9

What is the difference between nerves and hormones?

Answer 9

Hormones are slower and act for a longer time in a more general way compared to the fast, short, precise nerves.

Question 10

What happens if the blood glucose level is too high?

Answer 10

Insulin is secreted by the pancreas and the glucose is taken into the liver and turned into glycogen.

Question 11

What happens if the blood glucose level is too low?

Answer 11

Glucagon is secreted by the pancreas to alert the liver and the liver turns the stored glycogen back into glucose.

Question 12

What is type 1 diabetes?

Answer 12

When the pancreas produces very little insulin so the blood glucose levels are too high.

Question 13

What is type 2 diabetes?

Answer 13

When someone becomes resistant to their own insulin and does not respond to it so there is too much glucose.

Question 14

What is the job of the kidneys?

Answer 14

The kidneys filter the blood and make urine with unwanted substances in the blood.

Question 15

What is inside urine?

Answer 15

Urea - made up of ammonia which is a waste product from deamination. Ions can be wrong for the body. Water - there can be too much so that is dealt with.

Question 16

What is the concentration of urine controlled by?

Answer 16

A hormone called ADH monitors water content and uses negative feedback to say how much urine should be stored

Question 17

What happens if the kidneys fail?

Answer 17

There will be many waste substances stored up and the levels of ion and water will build up causing death.

Question 18

What does a kidney dialysis machine do?

Answer 18

It has a partially permeable membrane surrounded by dialysis fluid. Waste substances like ions and can go through but not big molecules. The dialysis fluid has the same levels of ions and glucose as blood so they will not diffuse over - only waste products diffuse across the barrier.

Question 19

What are the disadvantages of kidney dialysis?

Answer 19

Three 3-4 hour sessions are needed a week and it is unpleasant as well as costing a lot. It can cause blood clots.

Question 20

Talk about kidney transplants?

Answer 20

Can be rejected but are generally a cure - they have long waiting lists.

Question 21

What are the key dates in the menstrual cycle?

Answer 21

Day 1 - the uterus lining breaks
Day 4-14 - uterus lining builds up again
Day 14- an egg is released from an ovary
Day 14-28 - The lining waits for a fertilized egg and if it does not arrive it starts again.

Question 22

What does oestrogen do?

Answer 22

Causes the uterus lining to grow and stimulates LH and stops FSH

Question 23

What does follicle stimulating hormone do?

Answer 23

Causes the egg to mature and stimulates ovaries to produce Oestrogen.

Question 24

What does progesterone do?

Answer 24

Maintains lining of the uterus during the second half of the cycle. It inhibits LH and FSH

Question 25

What does the luteinising hormone do?

Answer 25

Stimulates the release of the egg.

Question 26

What is adrenaline for?

Answer 26

It is released in intense situations by the adrenal glands and gets the body into fight or flight mode like increasing heart rate.

Question 27

What is thyroxine for?

Answer 27

Released by the thyroid gland it regulates the speed at which chemical reactions in the body occur while resting (basal metabolic rate). It is also important for growth and development.

Question 28

What causes the release of thyroxine?

Answer 28

A negative feedback loop informs the pituitary gland if there is too much or little thyroxine and the thyroid-stimulating hormone is either increased or inhibited.