Animal Coordination, Control & Homeostasis

Question 1

Where are hormones produced?

Answer 1

In endocrine glands

Question 2

What is a hormone?

Answer 2

Chemical messengers that are carried in the blood to alter the activity of specific target organs

Question 3

Where is adrenaline produced?

Answer 3

In the adrenal glands

Question 4

What are the effects of adrenaline?

Answer 4

• Increased heart rate
• Increased blood pressure
• Increased blood flow to muscles
• Increased blood sugar levels by stimulating the liver to turn glycogen into glucose

Question 5

What is negative feedback?

Answer 5

Mechanism that makes sure substances (eg. hormones) stay at the right level

Question 6

What happens if blood glucose levels are too high?

Answer 6

The pancreas produces insulin which causes glucose to convert into glycogen and is stored in the liver

Question 7

What happens if blood glucose levels are too low?

Answer 7

The pancreas produces glucagon which causes the liver to break down the glycogen stores, releasing glucose into the blood

Question 8

Where is thyroxine produced?

Answer 8

In the thyroid gland

Question 9

What does thyroxine do?

Answer 9

Stimulate the metabolic rate

Question 10

What happens if thyroxine levels in the blood are low?

Answer 10

• The hypothalamus releases TRH
• This causes the pituitary gland to release TSH
• This causes the thyroid to produce more thyroxine

Question 11

What does TRH stand for?

Answer 11

Thyroid Releasing Hormone

Question 12

What does TSH stand for?

Answer 12

Thyroid Stimulating Hormone

Question 13

What happens when thyroxine levels in the blood are normal?

Answer 13

Thyroxine inhibits the release of TRH and TSH

Question 14

Which two hormones control the menstrual cycle?

Answer 14

• Oestrogen
• Progesterone

Question 15

Where is oestrogen produced?

Answer 15

The ovaries

Question 16

Where is progesterone produced?

Answer 16

The ovaries

Question 17

What does FSH do?

Answer 17

Causes an egg to mature

Question 18

What does LH do?

Answer 18

Stimulate the release of an egg

Question 19

What does FSH stand for?

Answer 19

Follicle Stimulating Hormone

Question 20

What does LH stand for?

Answer 20

Luteinising Hormone

Question 21

What does oestrogen do?

Answer 21

Involved in thickening and repairing uterus lining

Question 22

What does progesterone do?

Answer 22

Involved in maintaining the uterus lining

Question 23

Describe each stage of the menstrual cycle

Answer 23

• Days 1-5: Uterus lining sheds
• Day 14: Ovulation
• Days 15-28: Uterus lining thickens

Question 24

What is ovulation?

Answer 24

The release of an egg cell

Question 25

What is menstruation?

Answer 25

When the uterus lining is shed

Question 26

What is conception?

Answer 26

Fertilisation

Question 27

What is contraception?

Answer 27

The prevention of fertilisation

Question 28

What is the hormonal method of contraception?

Answer 28

Contraceptive pill

Question 29

How do contraceptive pills work?

Answer 29

- Contains oestrogen and/or progesterone - Oestrogen will inhibit FSH production

Question 30

What are the negatives of contraceptive pills?

Answer 30

Can cause changes in: - Weight - Mood - Blood pressure

Question 31

Name 4 non-hormonal methods of contraception

Answer 31

- Condoms - Diaphragms - IUDs - Surgical methods

Question 32

What are the negatives of non-hormonal methods of contraception?

Answer 32

- Condoms can tear or rip - IUDs must be fitted by a health professional and can cause an ectopic pregnancy - Surgical methods are permanent

Question 33

Name 2 examples of ART

Answer 33

- IVF - Clomifene therapy

Question 34

What does ART stand for?

Answer 34

Assisted reproductive technology

Question 35

What does IVF stand for?

Answer 35

In Vitro Fertilisation

Question 36

How does IVF work?

Answer 36

- Mother is given FSH & LH to stimulate the maturation of eggs - Eggs are collected and fertilised, with collected sperm from the father, in a petri dish in a lab - Fertilised eggs develop into embryos - Embryos inserted into mother’s uterus

Question 37

Why might a couple choose to use IVF?

Answer 37

- If mother has blocked oviducts - If father has issues with sperm quality

Question 38

How does clomifene therapy work?

Answer 38

- Drug is taken 5 days in a row each month - Causes more LH to be released at once - Promotes ovulation

Question 39

Why might someone use clomifene?

Answer 39

If mother doesn’t ovulate

Question 40

What is homeostasis?

Answer 40

The maintenance of a constant internal environment in the body, even when faced with external changes

Question 41

What is thermoregulation?

Answer 41

The maintenance of a 37°C internal body temperature

Question 42

Why is thermoregulation needed?

Answer 42

So enzymes work at their optimum temperature and do not denature

Question 43

What is the role of the hypothalamus is thermoregulation?

Answer 43

- Has thermal receptors to detect change in blood temperature - Controls effectors when responding to detected temperature change

Question 44

How does the body respond to an increase in body temperature?

Answer 44

- **Sweat glands** in the **dermis** release sweat onto the surface of the **epidermis** - The sweat evaporates, transferring heat to the environment - Vasodilation

Question 45

What happens if there is a decrease in body temperature?

Answer 45

- Skeletal muscles rapidly contract, causing shivering, causing heat to be released - Skin hairs raise, creating a layer of insulating air - Vasoconstriction

Question 46

What is vasoconstriction?

Answer 46

The narrowing of arterioles to decrease blood flow in skin capillaries

Question 47

What is vasodilation?

Answer 47

The dilation of arterioles to increase blood flow in skin capillaries

Question 48

What is the effect of type 1 diabetes?

Answer 48

The pancreas cannot produce insulin

Question 49

What are the effects of type 2 diabetes?

Answer 49

- Not producing enough insulin - Target organs not responding properly to insulin

Question 50

How can type 1 diabetes be controlled?

Answer 50

Injecting insulin

Question 51

How can type 2 diabetes be controlled?

Answer 51

- Change in diet - Regular exercise

Question 52

What is osmoregulation?

Answer 52

The control of water and mineral ion levels in the blood

Question 53

Why is osmoregulation needed?

Answer 53

- To balance water concentration between inside and outside cells - If a cell has too much water it could swell and burst - If a cell has too little water it could become shrivelled and not function

Question 54

How is urea produced?

Answer 54

From the breakdown of excess amino acids in the liver

Question 55

What happens during filtration in the nephron?

Answer 55

- Blood is filtered at high pressure - Large molecules stay in the blood - Small molecules (eg. urea, water, & mineral ions) pass into the nephron

Question 56

What happens during selective reabsorption in the nephron?

Answer 56

- The kidneys selectively reabsorb molecules needed in the body - These include water, mineral ions & glucose - The remaining molecules travel through the ureter to the bladder as urine

Question 57

In what blood vessels does blood pass through to get to the kidneys?

Answer 57

Renal arteries

Question 58

In what blood vessels do blood exit the kidney into?

Answer 58

Renal veins

Question 59

What does ADH stand for?

Answer 59

Anti Diuretic Hormone

Question 60

What is the role of the hypothalamus in osmoregulation?

Answer 60

- Has osmoreceptors that detect change in water concentration - Triggers the pituitary gland to release ADH