CNS
PNS - Peripheral Nervous System
- Central Nervous System
- Consists of the interconnecting neurones which connect
the CNS to the organs, and allow the required two way
communication, via electrical signals.
- Consists of two components - Brain & Spinal Cord
- Receives and processes information from sensory organs to
determine both our internal (visceral information) and
external (sensory information) environments and conditions.
- Upon processing the sensory input, the brain then makes
decisions based on the information, and relays instructions in
the form of a second electrical signal to an effector organ
such as a muscle.
Example Pathway
Sense
Optic Nerve
(Increase in light intensity)
Afferent
Visual Cortex
of the Brain
Afferent neurones transmit
sensory and visceral information
to the CNS
CNS
These are such things as somatic
senses, and sensory organs, pH,
fullness of stomach and
temperature.
Somatic
(Voluntary)
Consists of motor neurones
which regulate muscle function
and voluntary/conscious actions.
Sympathetic
Motor
Neurone
Efferent
Pupil etc.
Effector
Organ
Efferent neurones transmit
instructions and information
from the CNS to the effector
organs such as muscle, that
will then perform the
appropriate function in
response to the stimulus
Autonomic
(Involuntary)
Consists of neurones which regulate internal organs, glands, a
number of muscles, breathing flow, heart rate, and all
unconscious actions.
(fight or flight)
Will divert blood flow and resources away from non
critical area’s, redirecting it to the heart and muscle,
increasing awareness, strength and releasing the
neurotransmitter - adrenaline
Parasympathetic
(rest and normal
behaviour)
Responsible for normal behaviour in a resting state. It will
increase blood flow to area’s such as digestion, to absorb
nutrition, and repair any muscle damage, and wounds. Uses
the standard transmitter - acetyl choline