B1.2 Nerves and Hormones

Question 1

What is a receptor?

Answer 1

A receptor is a group of specialised cells that react to a stimulus. They detect a specific change in the environment.

EG
Receptor = eye
Stimulii = light

Question 2

What system involves the brain and spinal cord?

Answer 2

The central nervous system

Question 3

What are neurones?

Answer 3

Neurones are nerve cells that carry information in the form of tiny electrical signals

Question 4

What are the properties of a sensory neurone?

Answer 4

The sensory neurone SENSES the stimuli and stimulates signals that are sent to the brain and spinal cord

Question 5

Which neurone transmits messages thoughout/within the central nervous system?

Answer 5

The relay neurone

Question 6

What does the motor neurone do?

Answer 6

Carry signals from the central nervous system to the effectors (that carry out the action)

Question 7

What is the axon of a motor neurone

Answer 7

The central stem of the neurone

Question 8

Where are the dendrites?

Answer 8

At the end of the motor neurone by the nucleus

Question 9

What is the synapse?

Answer 9

The gap where two neurones meet and an electrical signal is diffused accross

Question 10

How does a reflex action occur?

Answer 10

stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector

The actions do not interact with the brain

Question 11

What is an effector?

Answer 11

Any part of the body that produces a response

eg -> a muscle contracting, gland releasing

Question 12

What is the eye an example of?

Answer 12

A sense organ

Question 13

Which type of neurone transmits a signal from a sense organ to the central nervous system?

Answer 13

Sensory neurone

Question 14

What is a hormone?

Answer 14

A chemical substance produced by a gland and carried by the blood that alter the activity of target organs

Question 15

How are hormones and nerves similar?

Answer 15

They can both control the body

Question 16

What are the characteristics of a hormone?

Answer 16

Signal : chemical
transmission : nerve cells in the blood stream
Effectors : cells in particular tissues
Response : chemical change
Speed of response : slow
Duration of response : Long ( until hormone breaks down)

Question 17

What are the characteristics of a nerve?

Answer 17

Signal : electrical
transmission : Nerve cells
Effectors : Muscles or glands
Response : Muscle contraction or secretion
Speed : very rapid
duration : short ( until nerve impulses stop)

Question 18

What hormone does the ovary produce?

Answer 18

Oestrogen

Question 19

Where is insulin produced?

Answer 19

The pancreas

Question 20

What controls the pituatiry gland?

Answer 20

The hypothalimus in the brain

Question 21

Where is adrenalin produced?

Answer 21

The adrenal gland

Question 22

What and when are the four stages of the menstrual cycle?

Answer 22

Stage 1 (days 1-4)
the uterus sheds its lining (bleeding)
Stage 2 ( days 4-14 )
 the uterus lining is rebuilt, thick spongy layer
Stage 3 ( day 14) 
An egg is released from the ovary
Stage 4 (14 -28)
The uterus lining remains for the egg to be fertilised, if not the cycle begins again

Question 23

What major hormones are in the menstrual cycle?

Answer 23

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

Question 24

How is an egg released from the ovaries?

Answer 24

The pituitary gland causes the production of FSH which in turn causes an egg to mature
The ovaries release oestrogen which triggers the release of LH
LH (released by the pituitary gland) determines when an egg is released into the uterus

Question 25

What are the four types of pathogen that cause disease?

Answer 25

Virus
Bacteria
Fungi
Carcinogen