The Peripheral Nervous System

Question 1

How many pairs of cranial nerves

Answer 1

12 pairs

Question 2

How many pairs of spinal nerves

Answer 2

31 pairs

Question 3

Mixed nerves

Answer 3

Most spinal nerves and cranial nerves are called mixed nerves because they contain fibres that can transport impulses both TO and FROM the CNS.

Question 4

Afferent/sensory nervous system

Answer 4

Sensory neurons carry impulses into the CNS. These neurons can either be somatic sensory or visceral sensory

Question 5

Somatic sensory

Answer 5

Impulses from the skin and muscles

Question 6

Visceral sensory

Answer 6

Impulses from the internal organs

Question 7

Efferent/motor nervous system

Answer 7

Carry impulses out of the CNS. Can be divided into somatic or autonomic divisions.

Question 8

Somatic division

Answer 8

Motor neurons from the CNS to skeletal muscle (voluntary control)

Question 9

Autonomic division

Answer 9

Motor neurons to smooth muscle, cardiac and glands (involuntary control). Also divides into 2 divisions. Parasympathetic and sympathetic.

Question 10

Parasympathetic NS

Answer 10

Involved in ‘calm and conservative’ response to maintain homeostasis during relatively quiet conditions
- Neurotransmitter is acetylcholine

Question 11

Sympathetic NS

Answer 11

Involved in the ‘fight or flight’ responses which prepare the body for increased activity.
- Neurotransmitter is noradrenaline