Topic 7 - Animal Coordination, Control and Homeostasis

Question 1

What is a hormone?

Answer 1

A chemical messenger sent in the blood

Question 2

What is an endocrine gland?

Answer 2

A gland that produces a hormone

Question 3

Name 6 endocrine glands and the hormones they produce:

Answer 3

• Pituitary Gland: Many hormones
• Thyroid Gland: Thyroxine
• Pancreas: Insulin
• Adrenal Glands: Adrenalin
• Ovaries: Oestrogen
• Testes: Testosterone

Question 4

What are the three differences between neurones and hormones?

Answer 4

• Neurones are very fast, hormones are slower
• Neurones last a short time, hormones last a long time
• Neurones are very specific to an area, hormones are more general

Question 5

What does adrenalin prepare you for?

Answer 5

‘Fight or Flight’

Question 6

How does adrenalin work?

Answer 6

• Binds to receptors on heart, causing more constrictions, so heart rate and blood pressure increase
• Binds to receptors on liver, causing glycogen to break down into glucose, increasing blood sugar levels

Question 7

What is the purpose of a negative feedback system?

Answer 7

To keep the amount of a hormone in the blood at the correct/safe level

Question 8

What does thyroxine regulate?

Answer 8

Metabolism

Question 9

How does thyroxine work?

Answer 9

• When it is at a low level, the hypothalamus is stimulated to produce TRH
• TRH stimulates the pituitary to release TSH
• TSH stimulates the thyroid to release thyroxine
• When the level of thyroxine is too high, the hypothalamus’ production of TRH is inhibited

Question 10

How long is the menstrual cycle?

Answer 10

28 days

Question 11

How many stages are in the menstrual cycle?

Answer 11

4

Question 12

How long does each stage of the menstrual cycle last?

Answer 12

• Stage 1: Day 1 - Day 4
• Stage 2: Day 4 - Day 14
• Stage 3: Day 14
• Stage 4: Day 14 - Day 28

Question 13

What 4 hormones control the menstrual cycle?

Answer 13

• FSH
• LH
• Oestrogen
• Progesterone

Question 14

How can infertility be controlled?

Answer 14

• Clomifene therapy: Causing more FSH and LH to be produced, causing ovulation
• IVF: Collecting eggs and fertilising them in the lab, before putting them back into the woman

Question 15

What are the hormonal methods of contraception?

Answer 15

• Taking oestrogen every day to prevent egg maturation
• Taking progesterone stops sperm reaching the egg
• Contraceptive pill (oestrogen and progesterone)
• Contraceptive injection (progesterone)

Question 16

What are the physical barrier methods of contraception?

Answer 16

• Male Condom
• Female Condom
• Diaphragm

Question 17

What is homeostasis?

Answer 17

Maintaining a constant internal environment

Question 18

Give 3 examples of homeostasis:

Answer 18

• Osmoregulation
• Thermoregulation
• Blood glucose regulation

Question 19

What 2 hormones control blood glucose levels?

Answer 19

• Insulin

- Glucagon

Question 20

How are blood glucose levels controlled?

Answer 20

• If it is too high, insulin is added, which makes the liver turn glucose into glycogen
• If it is too low, glucagon is added, which makes the liver turn glycogen into glucose

Question 21

What is the main difference between type 1 and type 2 diabetes?

Answer 21

• Type 1 is caused by a lack of insulin

- Type 2 is caused by a resistance to insulin

Question 22

How can type 1 diabetes be treated?

Answer 22

• Insulin therapy

- Taking regular exercise

Question 23

What is the correlation between obesity and type 2 diabetes?

Answer 23

People who are obese (BMI > 30) are at higher risk of type 2 diabetes

Question 24

How can type 2 diabetes be treated?

Answer 24

• Healthy diet
• Regular exercise
• Losing weight

Question 25

What controls body temperature?

Answer 25

The Hypothalamus

Question 26

What does homeostasis maintain our body temperature at?

Answer 26

37°C

Question 27

What happens when we are too hot?

Answer 27

• We sweat to remove heat
• Hairs lie flat
• Blood vessels vasodilate to get rid of heat

Question 28

What happens when we are too cold?

Answer 28

• We don’t sweat
• Hairs stand up to trap heat
• Blood vessels vasoconstrict to stop heat being lost
• We shiver to increase respiration rate, which transfers more energy to heat the body

Question 29

What is the technical term for regulation of water?

Answer 29

Osmoregulation

Question 30

Why is water important?

Answer 30

Because it keeps cells functioning

Question 31

What system are the kidneys part of?

Answer 31

The urinary system

Question 32

What are the 3 main functions of the kidneys?

Answer 32

• Removing urea from the blood
• Adjustment of ion levels in the blood
• Adjustment of water levels in the blood

Question 33

What are nephrons?

Answer 33

Filtration units in the kidneys

Question 34

By what hormone is water reabsorption controlled?

Answer 34

ADH - Anti-Diuretic Hormone

Question 35

What happens if water is lost?

Answer 35

• Pituitary gland releases more ADH

- ADH makes the kidneys reabsorb more water

Question 36

What happens if water is gained?

Answer 36

• Pituitary gland releases less ADH

- Less ADH makes the kidneys reabsorb less water

Question 37

What does dialysis do?

Answer 37

Filters blood mechanically

Question 38

What is the problem with kidney transplants?

Answer 38

Kidney may be rejected by the perosn’s immune system and thus attacked by antibodies