Nervous system

Question 1

Neurones

Answer 1

• Transmit electrochemical signals called nerve impulses
• There are 3 types of neurones:
  1. Sensory neurones
  2. Relay neurones
  3. Motor neurones

Question 2

Synapse

Answer 2

The gap between neurones

Question 3

Sensory neurones

Answer 3

• Carry impulses from sense organs or receptors to the central nervous system

Identify:
- Odd protrusion at the side

Question 4

Relay neurones

Answer 4

• Provide connections between sensory and motor neurones and between themselves

Identify:
- Many short dendrites (the little nerve endings)
- Do not have myelin sheath (extra layer surrounding the nerve)

Question 5

Motor neurones

Answer 5

• Stimulate effectors
• Carry impulses from brain or spinal cord to effectors

Identify:
- Many short dendrites (the little nerve endings)
- May or may not have myelin sheath (extra layer surrounding the nerve)

Question 6

Reflex action

Answer 6

It is an immediate response to a specific stimulus without conscious control

Question 7

Reflex arc

Answer 7

It is a pathway by which impulses travel from receptor to effector

Question 8

Process of a reflex action

Answer 8

1. A receptor detects the stimulus
2. Nerve impulse is generated and travels along the sensory neurone to the spinal cord
3. In the spinal cord, nerve impulses are transmitted across a synapse to the relay neurone and then across another synapse to the motor neurone
4. Nerve impulse travel along the motor neurone to the effector
5. Effector muscle contracts

Question 9

Similarities between endocrine and nervous system

Answer 9

1. Both involve stimulus being detected by the body
2. Both involve signal that is transmitted
3. Both involve an effector

Question 10

Differences between endocrine and nervous system

Answer 10

1. The nervous system is transmitted by nerve impulses by neurons while the endocrine system is transmitted by hormones in the bloodstream
2. The nervous system acts immediately while the endocrine system is slower and relatively slow-acting
3. The effects of the nervous system are often short-term while the effects of the endocrine system can be both short and long-term
4. The nervous system can be voluntary or involuntary while the endocrine system is always involuntary