B7 - Animal Coordination, Control and Homeostasis

Question 1

Define

hormones.

Answer 1

chemicals which are released directly into the blood

Question 2

Define

endorcine glands.

Answer 2

the glands that produce and secrete hormones

Question 3

What are the 6 endorcine glands that you need to know?

Answer 3

1. pituitary gland
2. thyroid gland
3. adrenal gland
4. pancreas
5. ovaries
6. testes

Question 4

What is the difference in action speed between

neurones and hormones?

Answer 4

neurones - very fast action
hormones - slower action

Question 5

What is the difference between duration of action between

neurones and hormones?

Answer 5

neurones - act for a very short time
hormones - act for a long time

Question 6

What is the difference between area acted on between

neurones and hormones?

Answer 6

neurones - act on a very precise area
hormones - act in a more general way

Question 7

Where are the adrenal glands located?

Answer 7

just above the kidneys

Question 8

What hormone do the adrenal glands release?

Answer 8

adrenalin

Question 9

What two areas does adrenalin bind to the receptors of?

Answer 9

• heart
• liver

Question 10

How does adrenalin affect the

heart?

and why?

Answer 10

it causes the heart muscle to contract more frequently and with more force, so heart rate and blood pressure increase

this increases blood flow to the muscles, so the cells receive more oxygen and glucose for increased respiration

Question 11

How does adrenalin affect the

liver?

and why?

Answer 11

it causes the liver to break down its glycogen stores to release glucose

this increases the blood glucose level, so there’s more glucose in the blood to be transported to the cells

Question 12

What hormone does the thyroid gland release?

Answer 12

thyroxine

Question 13

What occurs when the blood thyroxine level is lower than normal?

(3 steps)

Answer 13

1. The hypothalamus is stimulated to release TRH.
2. TRH stimulates the pituitary gland to release TSH.
3. TSH stimulates the thyroid gland to release thyroxine, so the blood thyroxine level rises back towards normal

(the opposite occurs when levels rise above normal)

Question 14

Define

menstrual cycle.

Answer 14

the monthly sequence of events in which the female body releases and egg and prepares the uterus in case the egg is fertilised

Question 15

What occurs during stage 1 of the menstrual cycle?

and how long is this stage?

Answer 15

menstruation starts
the lining of the uterus breaks down and is released

4 days long (on average)

Question 16

What occurs during stage 2 of the menstrual cycle?

and how long is this stage?

Answer 16

the uterus lining is repaired until it becomes a thick spongy layer full of blood vessels ready for a fertilised egg to implant there

10 days long (on average)

Question 17

What occurs during stage 3 of the menstrual cycle?

Answer 17

an egg develops and is released from the ovary

Question 18

What occurs during stage 4 of the menstrual cycle?

and how long is this stage?

Answer 18

the uterus lining is maintained for about 14 days
if no fertilised egg has landed on the uterus wall by day 28, the spongy lining starts to break down again and the whole cycle starts over

14 days long (on average)

Question 19

Define

ovulation.

Answer 19

the release of an egg from the ovary

Question 20

What are the 4 key hormones in the

menstrual cycle?

Answer 20

• FSH (follicle-stimulating hormone)
• Oestrogen
• LH (luteinising hormone)
• Progesterone

Question 21

What gland is FSH released from?

Answer 21

the pituitary gland

Question 22

What gland is oestrogen released from?

Answer 22

the ovaries

Question 23

What gland is LH released from?

Answer 23

the pituitary gland

Question 24

What gland is progesterone released from?

Answer 24

the corpes luteum

Question 25

# Define follicle.

Answer 25

an **egg** and its surrounding cells

Question 26

What does FSH do? | (2 things)

Answer 26

- causes a **follicle** to **mature** in one of the ovaries - stimulates **oestrogen** production

Question 27

What does oestrogen do? | (2 things)

Answer 27

- causes the lining of the uterus to **thicken** and **grow** - stimulates a **rapid increase of LH** (at a high level)

Question 28

What does LH do? | (2 things)

Answer 28

- stimulates **ovulation** - the follicle ruptures and the **egg is released** - stimulates the **remains** of the **follicle** to develop into a structure called a **corpus luteum**

Question 29

What does progesterone do? | (2 things)

Answer 29

- **maintains** the lining of the uterus - **inhibits** the release of **FSH** and **LH**

Question 30

What does the drug clomifene do to help fertility?

Answer 30

it causes more **FSH** and **LH** to be released | (these **stimulate egg maturation and ovulation**)

Question 31

What is the IVF process? | (5 steps)

Answer 31

1. **FSH** and **LH** are given to a woman to **stimulate egg production**. 2. Some **eggs** from the woman's ovaries are collected. 3. These are fertilised in a **lab** using the man's **sperm**. 4. These are then grown into **embryos**. 5. Once the embryos are **tiny balls of cells**, one or two of them are **transferred** to the woman's uterus to improve the chance of **pregnancy**.

Question 32

# Define Assisted Reproductive Technology (ART).

Answer 32

a fertility treatment that involved eggs being handled (and usually fertilised) **outside of the body** | IVF is an example of this

Question 33

How can oestrogen be used as a contraceptive?

Answer 33

it **prevents** the **release** of an **egg** if taken **every day** because **permanently high** levels of oestrogen **inhibits** the production of **FSH** | (so, after a while, **egg development** and **production stop**)

Question 34

How can progesterone be used as a contraceptive?

Answer 34

it **reduces fertility** by stimulating the production of **thick cervical mucus** ## Footnote (this **prevents** and **sperm** getting through the **cervix** and reaching an egg)

Question 35

# What are some positives of hormonal methods of contraception? | (2)

Answer 35

- they are **generally** (when **used correctly**) **more effective** at **preventing pregnancy** than barrier methods - the couple don't have to stop and think about contraception **each time** they intercourse

Question 36

# What are some negatives of hormonal methods of contraception? | (2)

Answer 36

- they can have **unpleasant side-effects** - they **don't protect** against **STIs**

Question 37

# What are three examples of homeostasis?

Answer 37

1. **Osmoregulation** (regulating **water** content) 2. **Thermoregulation** (regulating **body temperature**) 3. **Blood glucose** regulation

Question 38

# What occurs to stabilise blood glucose concentration when the blood glucose concentration is too high? | (3 steps)

Answer 38

1. **Insulin** is secreted by the **pancreas**. 2. This makes the **liver** turn **glucose** into **glycogen**. 3. So more **glucose** moves from blood into **liver** and **muscle** cells.

Question 39

# What occurs to stabilise blood glucose concentration when the blood glucose concentration is too low? | (3 steps)

Answer 39

1. **Glucagon** is secreted by the **pancreas**. 2. This makes the **liver** turn **glycogen** into **glucose**. 3. This **glucose** is released into blood by the **liver**.

Question 40

# What is type 1 diabetes? | and what can this lead to?

Answer 40

a condition where the **pancreas produces very little or no insulin** | a person's blood glucose can **rise** to a level that can kill them

Question 41

How can type 1 diabetes be 'treated'?

Answer 41

**Insulin therapy**: **insulin** is regularly **injected** into fatty tissue where it will enter the bloodstream | (e.g. at mealtimes)

Question 42

# What is type 2 diabetes?

Answer 42

a condition where a person becomes **resistant to insulin** | so blood glucose level **rises**

Question 43

# What is the formula for BMI?

Answer 43

mass (kg) / height (m) ^2

Question 44

# What is the formula for waist to hip ratio?

Answer 44

waist circumference (cm) / hip circumference (cm)

Question 45

What waist to hip ratios would be associated with an increased risk of type 2 diabetes?

Answer 45

**1 for males** and **0.85 for females**

Question 46

How can type 2 diabetes be controlled? | (5 ways)

Answer 46

- eating a **healthy diet** - getting regular **exercise** - **losing weight** - **medication** - **insulin injections**

Question 47

# What should our core body temperature be?

Answer 47

37°C

Question 48

# What occurs when you are too hot? | (3 things)

Answer 48

- **erector muscles** relax (so **hairs** lie flat) - **lots of sweat** is produced in **sweat glands** - **blood vessels** close to the surface of the skin **dilate** (widen)

Question 49

# How does sweat work to cool you down?

Answer 49

when the sweat **evaporates** it **transfers energy** from your skin to the environment, cooling you down

Question 50

# What is vasodilation? | and what does this do?

Answer 50

when **blood vessels** close to the surface of your skin **dilate** (widen) ## Footnote it allows **more blood** to flow near the **surface** so it can **transfer more energy** into the **surroundings**, which cools you down

Question 51

# What occurs when you are too cold? | (4 things)

Answer 51

- **erector muscles** contract (**hairs** stand on end to trap an **insulating layer of air** near the surface of the skin, which helps keep you warm) - **very little sweat** is produced - blood vessles near the surface of the skin **constrict** (**vasoconstriction**) - you **shiver** (your muscles contract automatically)

Question 52

# How does shivering work to warm you up?

Answer 52

this increases your rate of **respiration**, which transfers more **energy** to **warm** the body

Question 53

# What are the three main roles of kidneys?

Answer 53

1. **Remove urea** from the blood 2. **Adjust the ion levels** in the blood 3. **Adjust the water content** of the blood

Question 54

# What happens in each nephron of a kidney? | (3 steps) (good luck with this one)

Answer 54

1. The **liquid** part of the blood is **forced out** of the **glomerulus** and into the **Bowman's capsule** at **high pressure** (**ultrafiltration**). **Bigger** molecules and **blood cells** can't pass through the membranes and are **not forced out**. 2. As the liquid flows along the nephron **useful** substances are **reabsorbed**. (e.g. **glucose**, **sufficient ions**, **sufficient water**) 3. Whatever isn't reabsorbed continues **out** of the **nephron** via the **collecting duct**. It then passes into the **ureter** and down to the **bladder** as **urine**. Urine is released through the **urethra**.

Question 55

# State the journey of urine. | (starting from the renal artery) (10 stages)

Answer 55

1. Renal artery 2. Glomerulus 3. Bowman's capsule 4. Proximal convoluted tubule 5. Loop of Henle 6. Distal convoluted tubule 7. Collecting duct 8. Ureter 9. Bladder 10. Urethra

Question 56

# What is the role of ADH? | and what does it stand for?

Answer 56

to control the amount of water reabsorbed by the kidney nephrons | anti-diuretic hormone

Question 57

# How is water content regulated? | (3 steps)

Answer 57

1. The brain **monitors the water content of the blood**. 2. It instructs the **pituitary gland** to release **ADH** into the blood according to how much is needed. 3. ADH makes the **collecting ducts** of the **nephrons more permeable** so that **more water** is **reabsorbed** back into the blood.

Question 57

# What gland is ADH released from?

Answer 57

the pituitary gland

Question 58

# What cures are there for kidney disease?

Answer 58

kidney transplant

Question 59

# What precautions are taken to reduce the risk of a donor kidney being rejected by the patient's immune system? | (2 things)

Answer 59

- a **donor** with a tissue type that **closely matches** the patient is chosen - the patient is treated with **drugs** that suppress the **immune system**, so that their immune system **won't attack** the transplanted kidney