Chapter 16: Coordination in humans

Question 1

Components of the CNS (Central nervous system) and PNS (Peripheral nervous system)

Answer 1

CNS: Brain, spinal cord
PNS: Cranial nerves and spinal nerves

Question 2

Cranial nerves VS spinal nerves

Answer 2

Cranial nerves: link effectors and receptors in the head and the neck to the brain
(e.g. optic nerves, auditory nerves)

Spinal nerves link effectors and receptors in the rest of the body to the spinal cord.

Question 3

Withdrawal reflex

Answer 3

• The hand touches a sharp object.
  Pain receptors are simulated and generate nerve impulses.
  Sensory neurone transmits the nerve impulses to interneurone in the spinal cord
  Interneurone relays nerve impulses to the motor neurone
  Motor neurone transmits nerve impulses to the biceps
  Biceps contract and the hand withdraws to prevent further damage