Download Nervous System

HLTAP301A
Communication and control centre of the body
Structurally divided into CNS and PNS
1. CNS

Brain and spinal cord
2. PNS

Spinal nerves and cranial nerves

Further divided into
1. Sensory which monitors changes and carry info
to CNS
2. Motor info is sent from CNS towards muscles
and glands causing a response

Most important in the transmission of
information

Support, protect, insulate, nourish and
generally care for neurons

1.
2.
3.
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Covered by 3 layers of membrane called
meningies
Dura mater is outer most layer
Arachnoid mater is middle layer
Pia mater is inner most layer
Between arachnoid and pia is the
subarachnoid space filled with CSF
CSF provides nourishment to CNS as well as
cushioning CNS
Divided into functional sections
1. Cerebrum

Largest section

Divided into R and L hemispheres

Each hemisphere has 4 lobes

Functions include memory, association,
thought and judgement
2. Cerebellum
 Second largest section
 Posterior and inferior to cerebrum
 Function is to coordinate voluntary
movements by maintaining balance, posture
and muscle tone
3. Brain stem
 Connects cerebrum to spinal cord
 Provides a pathway for ascending and
descending tracts
 Divided into sections called
1. Midbrain
2. Pons
3. Medulla oblongata
1.






Frontal lobe
Motor area
Personality
Behaviour
Emotive expression
Intellectual functions
Memory storage
2. Parietal lobe
 Sensory area
 Taste
 Speech
 reading
3. Occipital lobe
 Vision
 Reading interpretation
 Judging distances
 Seeing in 3 dimension
4. Temporal lobe
 Hearing
 Smell
 Taste
 Memory storage
 Part of speech area
5. Thalamus
 Relays sensory information to cerebrum
6. Hypothalamus
 Regulate temperature
 Water balance
 Sex
 Thirst
 Appetite
 Pleasure and fear
7. Midbrain
 Relays sensory and motor information
8. Pons
 Plays a role in respiration
9. Medulla oblongata
 Regulate heart rate, blood flow, blood
pressure, respirations
 Reflex for coughing, sneezing, swallowing
and vomiting
9. Cerebellum
 Coordinates voluntary muscle activity
 Maintains balance and muscle tone
Divided into
1.
Somatic NS

Controls skeletal muscles

12 pairs cranial nerves supplying above the neck

31 pairs supplying trunk and limbs
2. Autonomic NS

Controls involuntary movements of internal organs
and gland secretions

Also divided into
1.
Sympathetic NS which acts when we are excited,
frightened or exercising.
2.
Parasympathetic NS which slows body functions
back down