1.1 | Human Nervous System

• The human nervous system is an important control system for tracking and transmitting information in the body as well as coordinating body activity.

• Functions of the human nervous system: - stimulation effects, transmitting information, impulse interpretations and response outcomes.

• Two structures of the human nervous system: -

1. Central (Brain & Spinal cord)

2. Peripheral (Cranial nerves & Spinal nerves)

• Peripheral nervous system consists of:

  • 12 pairs of cranial nerves connecting the brain to the sensory and internal organs􀁴􀀁 􀀔􀀒􀀁􀁑􀁂􀁊􀁓􀁔􀀁􀁐􀁇􀀁􀁔􀁑􀁊􀁏􀁂􀁍􀀁

  • 31 pairs of spinal nerves connecting the spinal cord to the skeletal muscles

The flow of stimulus to the response

Stimulus → Affector → Brain → Effector → Response

• The types of response are divided into two: -

1. Voluntary Actions - conscious  actions and conducted under one’s will. Controlled by the brain

Examples - writing, reading, running and talking

2. Involuntary Actions - occur immediately without conscious control or prior thoughts. Involving medulla oblongata & spinal cord

• External control is divided into two parts:-

a) involving medulla oblongata

• Heartbeat, saliva, respiratory & peristalsis

b) involving the spinal cord (reflex)

• Draws hands / feet when exposed to hot or sharp objects