TERM DEFINITION
Nervous System A specialised network of cells in the human body and is our
primary internal communication system. It consists of the central
nervous system (CNS) and the peripheral nervous system (PNS)
Central Nervous System (CNS) Consists of the brain and the spinal cord and is the origin of all
complex commands and decisions. It plays a primary role in
receiving information from various areas of the body and then
coordinating this activity to produce the body's responses.
Brain The brain receives information from sensory receptors and sends
messages to muscles and glands. It is the centre of all conscious
awareness and is divided into different lobes with different
functions.
Spinal cord An extension of the brain that is responsible for reflex actions. It
allows the brain to monitor processes such as breathing and to
control voluntary movements.
Peripheral Nervous System Sends information to the CNS from the outside world and
(PNS) transmits messages from the CNS to muscles and glands in the
body via million of neurons (nerve cells).
Somatic Nervous System The part of the PNS that controls muscle movement and receive
information from sensory receptors. It is responsible for carrying
motor and sensory information both to and from the CNS.
Autonomic Nervous System Regulates a variety of body process that takes place without
conscious effort. It is the part of the PNS that is responsible for
regulating involuntary body functions, such as heartbeat, blood
flow, breathing, and digestion.
Sympathetic Nervous System Regulates the fight to flight responses by controlling over the
necessary bodily changes needed when we are faced with a
situation where we may need to defend ourselves or
escape. This includes increasing heart rate, dilating eye pupils
and inhibiting digestion.
Parasympathetic Nervous Relaxes the individual once the emergency has passed, e.g. slows
System the heart rate down, reduces blood pressure and constrict
pupils. It conserves the body’s natural activity by decreasing
activity or maintaining it. The parasympathetic leads to
decreased arousal.