Endocrine System

Question 1

What is a hormone?

Its function

Answer 1

Chemical molecule carried in the blood.
Controls activities in the organs
Secreted by glands
Usually have a long lasting effect.

Question 2

Compare nerves with hormones?

Answer 2

Nerves:

• Faster
• Act for a shorter time
• Act on a precise area

Hormones:

• Slow action
• Act for a longer time
• Act in a more general way.

Question 3

Pituitary Gland.

Answer 3

Master gland, secretes many hormones.
Controls growth in children
Stimulates thyroxine production
Stimulates ovaries to make eggs and testes to produce sperms.
ADH
TSH
FSH
LH

Question 4

Thyroid

Answer 4

Releases thyroxine which controls metabolic rates by targeting many organs..

Question 5

Adrenal Gland

Answer 5

Produces adrenaline hormones to prepare the body.

hormone: aldosterone which controls the concentration of salt and water around the body.

Question 6

Testes

Answer 6

Releases hormone testosterone, increases muscle mass density, and develops secondary sexual features.

Question 7

Pancreas

Answer 7

Produces hormone INSULIN which controls blood sugar levels.
Makes glucagon involved in regulating blood sugar levels
Targets the liver.

Question 8

Ovary

Answer 8

Releases OESTROGEN and PROGESTERONE
controls the menstrual cycle
and female sexual characteristics.

Question 9

Causes of high blood glucose level

Answer 9

• eating too many carbohydrates

- Diabetes

Question 10

Causes of low blood glucose levels

Answer 10

• Vigorous exercise

- Normal metabolism of cells removes glucose.

Question 11

Define,
Glucagon
Glycogen
Glucose

Answer 11

Glucagon is a hormone that makes our liver breakdown glycogen and covert it into glucose.

Glycogen is an insoluble sugar used for storage in the liver.

Glucose is a soluble sugar .

Question 12

What happens when blood glucose levels are too high.

Answer 12

Pancreas detects level too high
secretes insulin
Insulin moves glucose from blood to liver.
Insulin makes liver turn glucose to glycogen so that it can be stored.
Blood glucose levels decrease.

Question 13

What happens when blood glucose levels are too low.

Answer 13

Pancreas secretes hormone Glucagon
Glucagon makes liver turn glycogen into glucose.
Glucose released back into blood.
Blood glucose levels increase.

Question 14

How can an excess amount of lipids lead to obesity?

Answer 14

If your muscles are full and the glycogen is stored in the liver, if you regularly consume food that is more than what liver and muscles can store, then all the excess glucose will be stored as lipids.

Question 15

What is diabetes?

Answer 15

A condition affecting the ability to control blood sugar levels.

Question 16

Summary of type 1 diabetes.

Answer 16

• When pancreas doesn’t produce enough insulin.

- Treated by Insulin therapy, when insulin is injected into the body to remove the glucose as soon as it is digested.

Question 17

Why can’t you take insulin as a tablet.

Answer 17

Insulin is a protein ad hormone, the stomach would not digest it before it gets a chance to work if it was a tablet.

Question 18

Summary of type 2 diabetes.

Answer 18

• Body becomes insulin resistant, our cells stop responding to insulin.
• Treated by a carbohydrate controlled diet and lifestyle choices e.g exercise.

Question 19

Why do people with Type 1 diabetes urinate and feel thirsty all the time?

Answer 19

Due to lack of insulin, the glucose is excreted through urine, because you urinate more, you feel more thirsty.

Question 20

Why do people with Type 1 diabetes lose weight?

Answer 20

They lose weight because our cells stop responding and we begin to lack energy. So the body breakdowns fats and protein to use as a fuel instead, so you lose weight.

Question 21

Curing Type 1 diabetes

Answer 21

• Pancreas transplants, but limited success.
• Turn mouse pancreas cells that normally turn enzymes into insulin producing cells through genetic engineering. Same could be done for humans.

Question 22

Curing Type 2 diabetes.

Answer 22

• carbohydrate controlled diet
• lose weight
• regular exercise

Question 23

The role of Kidneys

Answer 23

-Act as filters to clean the blood.
- They make urine by taking waste products.
As substances pass through kidneys, they are filtered out.
Useful substances like glucose are then re-absorbed back through a process called selective reabsorption.

Question 24

What substances are removed from the body in urine?

Answer 24

• Urea
• Ions
• Water

Question 25

Urea

Answer 25

Proteins broken into amino acids.
Excess aa converted to fats and carbohydrates.
In liver, the aa are deaminated to form Ammonia.
Ammonia is toxic so its converted back to urea in liver.
Urea goes to kidney, its filtered out and excreted from body as urine.

Question 26

Ions

Answer 26

Taken in by food and absorbed into the blood.
Having the wrong amount of ion and water content damages cells
Some ions lost through sweat.
Kidney maintains the ion balance.
Re-absorbs the right amount of ions after filtration.

Question 27

Water

Answer 27

Needs to be constantly balanced.
We lose water from the skin in sweat and from lungs when breathing out.
Kidneys remove excess water through urine.

Question 28

Role of ADH

Answer 28

ADH controls urine concentration and affects the permeability of tubules.

Question 29

How does ADH control the conc of urine t

Answer 29

Negative feedback

Question 30

Well hydrated

Answer 30

Blood water level is high
Less ADH is released.
Low permeability of tubules.
LESS water re-absorbed
Dilute and yellowy urine

Question 31

De hydrated

Answer 31

Blood water level is too low
more ADH is released.
High permeability of tubules.
More water is reabsorbed.
Concentrated and dark urine.