B1.6 Nervous System and Hormones

Question 1

Nervous system

Answer 1

The network of nerve cells and fibres that transmits nerve impulses between parts of the body

Question 2

Neurones

Answer 2

Basic cells of the nervous system that carry electrical impulses around the body

Question 3

Electrical impulses

Answer 3

The impulses or signals that are carried by neurones

Question 4

Central nervous system (CNS)

Answer 4

Brain and spinal cord

Question 5

Stimulus

Answer 5

A change in an organism’s surroundings

Question 6

Receptors

Answer 6

Special structures that allow living organisms to sense the conditions of their internal or external environment

Question 7

Sense organs

Answer 7

Clusters of receptor cells that respond to specific stimuli such as light, sound, touch, temperature, chemicals and then relay this information as electrical impulses along neurones to the central nervous system

Question 8

Sensory neurone

Answer 8

A neurone that carries impulses from the sensory organs to the central nervous system

Question 9

Coordinator

Answer 9

The central nervous system which formulates a response to a stimulus before sending impulses to an effector

Question 10

Motor neurone

Answer 10

A neurone that sends impulses from the CNS to an effector

Question 11

Effector

Answer 11

A structure that acts in response to a stimulus such as muscles which contract or glands which secrete hormones

Question 12

Response

Answer 12

A reaction to a stimulus

Question 13

Reflex arc

Answer 13

A shorter nerve pathway involved in a reflex action made up of a sensory neurone, relay neurone and a motor neurone

Question 14

Association neurone

Answer 14

A short type of neurone that is involved in reflex actions and is found in the spinal cord

Question 15

Reflex response

Answer 15

A quick and involuntary reaction to a stimulus such as moving a hand away from a hot object, blinking or pupil size adjusting in response to light changes

Question 16

Voluntary versus reflex responses

Answer 16

Voluntary responses are conscious and involve the brain, reflex responses are not conscious and are much quicker than voluntary responses

Question 17

Nature of message for the hormonal (endocrine) system

Answer 17

Chemical messengers known as hormones

Question 18

Nature of message for the nervous system

Answer 18

Electrical impulses or signals known as nerve impulses

Question 19

How hormones are transmitted

Answer 19

Hormones are secreted by specialised tissues and organs called glands, the hormones travel around the blood and reach many organs but only have an effect on target organs, which causes them to create a response

Question 20

How nerve impulses are transmitted

Answer 20

Nerve impulses begin at receptor cells which pass on the electrical impulses across a series of nerve cells (called neurones) before reaching the brain or spinal cord, new impulses are then transmitted from the brain to target effectors to create a response

Question 21

Duration of effect and speed of hormones

Answer 21

Hormones are much slower than nerve impulses but last for a very long time

Question 22

Duration of effect and speed of nerve impulses

Answer 22

Nerve impulses travel incredibly fast but are relatively short-lived