Topic 7 : Animal Coordination, Control and Homeostasis

Question 1

Where are hormones made and how do they reach target organs?

Answer 1

Hormones are produced in endocrine glands and travel through the bloodstream to target organs.

Question 2

Name the main endocrine glands.

Answer 2

Pituitary gland, thyroid, pancreas, adrenal glands, ovaries (females), and testes (males).

Question 3

What hormone is released during stress and where from?

Answer 3

Adrenaline, released by the adrenal glands.

Question 4

What are the effects of adrenaline?

Answer 4

Increases heart rate, blood pressure, blood flow to muscles, and blood sugar levels.

Question 5

How does adrenaline increase blood sugar?

Answer 5

It stimulates the liver to convert glycogen into glucose.

Question 6

What does thyroxine do in the body?

Answer 6

It regulates the metabolic rate.

Question 7

How is thyroxine regulated by negative feedback?

Answer 7

Low thyroxine causes TRH release, which triggers TSH, stimulating thyroxine production. Normal levels inhibit TRH and TSH.

Question 8

What is the role of oestrogen in the menstrual cycle?

Answer 8

It thickens the uterus lining and inhibits FSH.

Question 9

What is the role of progesterone in the menstrual cycle?

Answer 9

It maintains the uterus lining and inhibits LH and FSH.

Question 10

What hormone causes ovulation?

Answer 10

LH (Luteinising Hormone).

Question 11

What hormone stimulates egg development?

Answer 11

FSH (Follicle Stimulating Hormone).

Question 12

How does hormonal contraception prevent pregnancy?

Answer 12

It stops ovulation and thickens cervical mucus.

Question 13

How do barrier methods of contraception work?

Answer 13

They physically block sperm from reaching the egg.

Question 14

How is IVF used in assisted reproduction?

Answer 14

Eggs are collected, fertilised in a lab, and implanted into the uterus.

Question 15

What is clomifene therapy used for?

Answer 15

To stimulate ovulation by increasing FSH and LH levels.

Question 16

Why is maintaining a constant internal environment important?

Answer 16

It keeps conditions stable for enzyme action and cell function.

Question 17

What does thermoregulation control?

Answer 17

Body temperature to protect enzymes from denaturing or slowing down.

Question 18

What does osmoregulation control?

Answer 18

Water balance to prevent cells from swelling or shrinking.

Question 19

What does the skin do in temperature regulation?

Answer 19

The dermis detects changes; sweat glands cool the body; blood vessels adjust heat loss.

Question 20

What does the hypothalamus do in thermoregulation?

Answer 20

It monitors body temperature and sends signals to effectors.

Question 21

What is shivering and how does it help regulate temperature?

Answer 21

Rapid muscle contractions that generate heat.

Question 22

What is vasoconstriction?

Answer 22

Narrowing blood vessels to reduce heat loss.

Question 23

What is vasodilation?

Answer 23

Widening blood vessels to increase heat loss.

Question 24

What hormone controls blood glucose levels?

Answer 24

Insulin.

Question 25

How does insulin work?

Answer 25

It lowers blood glucose by helping cells absorb it and storing it as glycogen.

Question 26

What does glucagon do?

Answer 26

Raises blood glucose by converting glycogen to glucose in the liver.

Question 27

What causes type 1 diabetes?

Answer 27

The pancreas does not produce insulin.

Question 28

How is type 1 diabetes treated?

Answer 28

With insulin injections and controlled diet.

Question 29

What causes type 2 diabetes?

Answer 29

Cells become resistant to insulin, often linked to obesity.

Question 30

How is type 2 diabetes managed?

Answer 30

Healthy diet, exercise, and sometimes medication.

Question 31

What factors are linked to type 2 diabetes?

Answer 31

High BMI and waist:hip ratio.

Question 32

What is the formula for BMI?

Answer 32

BMI = weight (kg) ÷ height² (m²).

Question 33

What organs make up the urinary system?

Answer 33

Kidneys, ureters, bladder, and urethra.

Question 34

What happens in the glomerulus and Bowman’s capsule?

Answer 34

Blood is filtered under high pressure to remove small molecules like glucose, salts, and urea.

Question 35

Why don't proteins and blood cells pass through the glomerulus?

Answer 35

They are too large to pass through the Bowman capcules's membrabne.

Question 36

What is ultrafiltration?

Answer 36

Ultrafiltration is the process in the kidney where small molecules like water, glucose, ions, and urea are forced out of the blood in the glomerulus into the Bowman's capsule, under high pressure.

Question 37

What blood vessel carries unfiltered blood into the kidneys?

Answer 37

Renal artery.

Question 38

What blood vessel carries filtered blood out of the kidneys?

Answer 38

Renal vein.

Question 39

What blood vessel carries unfiltered blood into the glomerulus?

Answer 39

Afferent arteriole.

Question 40

What blood vessel carries filtered blood out of the glomerulus?

Answer 40

Efferent arteriole that still contains blood cells and proteins which were too big to be filtered.

Question 41

Why is the blood pressure higher than normal in the glomerulus?

Answer 41

The afferent arteriole entering the glomerulus has a wider diameter than the efferent arteriole that is leaving.

Question 42

What is selective reabsorption?

Answer 42

The reuptake of useful substances like glucose, water and ions in the nephron.

Question 43

What is the role of ADH in the kidney?

Answer 43

It makes the collecting duct more permeable so more water is reabsorbed.

Question 44

What are the two treatments for kidney failure?

Answer 44

Dialysis and kidney transplant.

Question 45

What is urea and how is it made?

Answer 45

A waste product formed when excess amino acids are broken down in the liver.

Question 46

Which part of the body is urine stored?

Answer 46

Bladder.

Question 47

By what process is glucose and ions reabsorbed?

Answer 47

Active transport which requires energy

Question 48

By what process is water reabsorbed?

Answer 48

Osmosis.

Question 49

How much of each substance is reabsorbed during selective reabsorption?

Answer 49

All glucose, some water, some ions, no urea.

Question 50

How is the concentration gradient created so water can be reasborbed via osmosis?

Answer 50

Loop of henle pumps salts (Na+ and Ca- ions) into the medulla which makes the water potential in the blood lower than in the medulla.

Question 51

What does the loop of henle do and how does it's length relate to the amount of water absorbed?

Answer 51

The loop of henle conserves water and the longer it is, the more water is absorbed - desert animals will have a longer loop of henle

Question 52

How does the collecting duct control how much water is reabsorbed based on the body's hydration level.

Answer 52

The hypothalamus detect dehydration with osmoreceptos -> sends signals to pituitary gland to secrete ADH (antidiuretic hormone) -> makes collecting duct more permeable -> more water absorbed.

Question 53

Why is there a partially permeable membrane between the patient's blood supply and the dialysis fluid?

Answer 53

So small molecules like excess water and ions and waste (urea) can diffuse across into the dialysis fluid but large molecules can't like proteins and blood cells.

Question 54

Why does the dialysis fluid have the same concentration of salts and glucose as the blood plasma?

Answer 54

So salts and glucose aren't removed from the blood.

Question 55

Why does the dialysis fluid need to be regularly replaced?

Answer 55

To keep dissolved substances at the right concentrations and to remove waste.

Question 56

Why is a dialysis machine used?

Answer 56

To filter the patient's blood as their kidneys can't properly do it.

Question 57

What are two solutions to kidney failure?

Answer 57

Dialysis machine or kidney transplants.

Question 58

What is the only current cure for kidney failure?

Answer 58

Kidney transplants.

Question 59

What are the risks to kidney transplants

Answer 59

The donor kidney can be rejected by the patients immune system and be attacked by antibodies -> treated like a foreign body.

Question 60

What precautions are taken to reduce the risk of donor kidney rejection?

Answer 60

Using a donor with a tissue type that closely matches the patient's. The patient is treated with drugs to suppress the immune system so they won't attack the transplanted kidney