Homeostasis and Response

Question 1

What is homeostasis?

Answer 1

The regulation of internal conditions of a cell or organism to maintain optimum conditions.

Question 2

What factors are controlled by homeostasis?

Answer 2

Blood glucose concentration, body temperature and water levels.

Question 3

What parts are in the control system?

Answer 3

Receptors, coordinators and effectors.

Question 4

What is the pathway of a reflex action?

Answer 4

Stimulus > Receptor > Sensory neurone > Relay neurone > Motor neurone > Effector > Response.

Question 5

How is a neurone adapted to its function?

Answer 5

They are very long to transmit impulses over a long distance.

Question 6

What is a synapse?

Answer 6

The gap between neurones.

Question 7

What is a reflex action?

Answer 7

An involuntary response to a stimulus.

Question 8

How do nerve impulses travel across a synapse?

Answer 8

Neurotransmitters diffuse across the synapse and bind with specific receptor molecules on the membrane of the next neuron.

Question 9

Why are reflex actions important?

Answer 9

Minimise damage to the body from potentially harmful conditions.

Question 10

What is the endocrine system?

Answer 10

A system of glands that secrete hormones directly into the bloodstream.

Question 11

What are the six main glands in the endocrine system?

Answer 11

Pituitary gland, pancreas, thyroid, adrenal glands, ovaries and testes.

Question 12

What are hormones?

Answer 12

They are chemical messengers released by glands into the blood and carried to a target organ or organs.

Question 13

What is the difference between hormonal and nervous responses?

Answer 13

Hormonal responses take longer than nervous responses.

Question 14

Which gland is known as the ‘master gland’?

Answer 14

The pituitary gland.

Question 15

Why is the pituitary gland important?

Answer 15

It controls the functions of many of the other endocrine glands.

Question 16

What happens when blood sugar levels increase?

Answer 16

Insulin is secreted from the pancreas (instructed by hypothalamus) for cells to absorb glucose. Excess glucose is converted to glycogen and stored in the liver if not used in respiration.

Question 17

What happens when blood sugar levels decrease?

Answer 17

The pancreas secretes glucagon to convert the glycogen (in the liver) back to glucose. When glucose concentration increases, glucagon secretion stops.

Question 18

What is negative feedback?

Answer 18

Reactions leading to the return of optimum concentrations or environments.

Question 19

Which organ is responsible for monitoring blood glucose?

Answer 19

The pancreas.

Question 20

Which hormone lowers blood glucose?

Answer 20

Insulin.

Question 21

Which hormone raises blood glucose?

Answer 21

Glucagon.

Question 22

Which molecule is used as a store of glucose?

Answer 22

Glycogen.

Question 23

What is Type 1 diabetes?

Answer 23

Where the pancreas fails to produce insulin.

Question 24

What is Type 2 diabetes?

Answer 24

Where the body does not respond to insulin.

Question 25

What is a treatment for Type 1 diabetes?

Answer 25

Insulin injections.

Question 26

What is a treatment for Type 2 diabetes?

Answer 26

Carbohydrate-controlled diet and exercise.

Question 27

How are hormones transported around the body?

Answer 27

In the bloodstream.

Question 28

What is the main male reproductive hormone?

Answer 28

Testosterone.

Question 29

What are the main female reproductive hormones?

Answer 29

Oestrogen and progesterone.

Question 30

What is the role of FSH?

Answer 30

It matures an egg in the ovaries.

Question 31

Where is FSH secreted from?

Answer 31

The pituitary gland.

Question 32

What is the role of oestrogen?

Answer 32

It maintains the uterus lining and inhibits FSH.

Question 33

Where is oestrogen secreted from?

Answer 33

The ovaries.

Question 34

What is the role of LH?

Answer 34

It stimulates ovulation.

Question 35

Where is LH secreted from?

Answer 35

The pituitary gland.

Question 36

What does FSH stand for?

Answer 36

Follicle stimulating hormone.

Question 37

What does LH stand for?

Answer 37

Luteinizing hormone.

Question 38

What is the role of progesterone?

Answer 38

To prepare the endometrium (lining of your uterus) for a fertilized egg to implant and grow.

Question 39

Where is progesterone secreted from?

Answer 39

The ovaries.

Question 40

Which hormone is used in the contraceptive pill?

Answer 40

Oestrogen to prevent the maturation of an egg by inhibiting FSH.

Question 41

What are some methods of contraception?

Answer 41

Barrier methods (diaphragm or condom), contraceptive pill, Intra-uterine device (IUD), Spermicidal agents, and surgical sterilisation.

Question 42

What is the contraceptive implant and how does it work?

Answer 42

It is a small plastic rod, around 4 cm long, that a doctor or nurse puts under the skin of your arm, preventing pregnancy by releasing progestogen to stop the ovaries releasing an egg each month.

Question 43

How does an IUD work?

Answer 43

It prevents pregnancy by releasing copper into the womb, killing sperm and making it difficult for the sperm to get to an egg and thins the womb lining, so there's less chance an egg will attach to it.

Question 44

What is the process of an IVF?

Answer 44

1. Give a mother FSH and LH to stimulate the maturation of several eggs. 2. Collect eggs from the mother and fertilise them with sperm from the father in a laboratory. 3. The fertilised eggs develop into embryos. 4. When they are tiny balls of cells, one or two embryos are inserted into the mother's uterus.

Question 45

What are the negative viewpoints and impacts of IVF?

Answer 45

They are expensive, not ethical in terms of natural conception, low success rates and stress for the parent.

Question 46

What does IVF stand for?

Answer 46

In vitro fertilisation.

Question 47

What is the role of adrenaline?

Answer 47

It increases the heart rate and boots oxygen delivery around the body.

Question 48

What is the role of thyroxine?

Answer 48

It stimulates the basal metabolic rate and plays an important role in growth and development.

Question 49

What is the basal metabolic rate?

Answer 49

The minimum amount of energy required for an organism to sustain life.

Question 50

In investigating reaction time, what two conditions should be kept the same?

Answer 50

The lighting and level of background noise.

Question 51

How can we investigate the effect of practice in reaction time experiments?

Answer 51

One person would catch the ruler a large number of times and look to see any differences in reaction time, with the reaction time assuptuously being shorter with practice.

Question 52

How can we investigate the effect of a dominant hand in reaction time?

Answer 52

Compare the test using a dominant hand, then a non-dominant hand of the same person. We may assume the reaction time for the dominant hand would be less as it is used more often.

Question 53

How can we investigate the effect of chemicals in reaction time?

Answer 53

One person drinks a measured amount of cola, half an hour before the experiment, and compare this reaction time to their normal reaction time.

Question 54

What is a problem of using cola when investigating chemical effects of reaction time?

Answer 54

There may be other chemicals in the cola, affecting reaction time. Using a caffeine-free cola, compare this reaction time to their normal reaction time.

Question 55

How can we assure safety when using chemicals to test the effect of reaction time?

Answer 55

Check for no medical issue: an allergy or heart condition. Test in a lab where hazardous chemicals are not normally used.