Human Biology

Question 0

What are receptors?

Answer 0

A group of cells which are sensitive to a stimulus. They change stimulus energy (eg light energy) into electrical impulses.

Question 1

What is a stimulus?

Answer 1

A change in the environment that you may need to react to.

Question 2

Give 3 examples of stimuli

Answer 2

(Any 3 from) Light, sound, touch, pressure, change in position or change in temperature.

Question 3

What does CNS stand for?

Answer 3

Central Nervous System

Question 4

What does the CNS consist of?

Answer 4

The brain and spinal cord only.

Question 5

What kind of receptors are in the eyes?

Answer 5

Light receptors.

Question 6

What is the function of sensory neurones?

Answer 6

They are the nerve cells which carry signals as electrical impulses from the receptors in the sense organs to the CNS.

Question 7

What is the function of Motor Neurones?

Answer 7

They are the nerve cells that carry signals to the effector muscles or glands.

Question 8

What is an effector?

Answer 8

Muscles and glands which respond to receptors. Muscles contract in response to a nervous impulse and glands secrete hormones.

Question 9

What is a reflex reaction?

Answer 9

A reflex is an automatic response to a stimulus. They help to prevent injury.

Question 10

What is the path of a reflex reaction?

Answer 10

1- Receptors detect stimuli
2- Message travels along sensory neurones
3- Message passed along a relay neurone in the spinal cord (bypasses brain).
4- Message travels along motor neurone
5- Message reaches effector and it reacts (either by contracting or secreting a hormone)

Question 11

What is a synapse?

Answer 11

The connection between two neurones. The nerve signal is transferred my chemicals which diffuse across the gap. These chemicals then set off a new electrical signal in the next neurone.

Question 12

What are hormones?

Answer 12

They are chemical messengers which travel in blood to activate target cells. (They are carried in blood plasma to target cells. Hormones are secreted by different glands.)

Question 13

Name a hormone produced by the pancreas.

Answer 13

Insulin

Question 14

What are the 4 stages of the menstrual cycle?

Answer 14

1- lining of the womb breaks down (day 1-)
2- lining of the womb builds up (day 4 to 14)
3- egg released (day 14)
4- lining of the womb maintained (until day 28)

Question 15

What are the three main hormones involved in the menstrual cycle?

Answer 15

FSH, Oestrogen and LH

Question 16

Where is FSH produced and what does it do?

Answer 16

Produced in the pituitary gland, causes an egg to mature in one of the ovaries and stimulates the production of oestrogen.

Question 17

Where is Oestrogen produced and what does it do?

Answer 17

It is produced in the ovaries, caused pituitary to produce LH and inhibits further release of FSH

Question 18

Where is LH produced and what does it do?

Answer 18

Produced by the pituitary gland and stimulates the release an egg at around the middle of the menstrual cycle.

Question 19

Which hormones are used in “the pill” (birth control)?

Answer 19

Oestrogen, as it prohibits the production of FSH and so eggs are unable to mature.

Question 20

Which hormone can be used to increase fertility?

Answer 20

FSH as it stimulates egg production in the ovaries (eggs mature).

Question 21

What are the stages of In Vitro Fertilisation (IVF)?

Answer 21

1- Hormones given to stimulate egg production
2- Oestrogen and Progesterone given to make embryo implantation more likely to succeed
3- Embryos implanted in womb

Question 22

What is homeostasis?

Answer 22

It is our body keeping a constant internal environment

Question 23

Name 4 body levels that need to be controlled

Answer 23

Ion content, water content, sugar content and temperature

Question 24

Why is our ideal body temperature 37C?

Answer 24

Because this is the temperature at which enzymes work best at.

Question 25

What is metabolic rate?

Answer 25

It is the rate at which chemical reactions occur in your body

Question 26

What are 3 factors can affect your metabolic rate?

Answer 26

(Any 3 from) Gender, Age, body temperature, amount of exercise, amount of fat, genetic factors etc