Divisions of nervous system
Part 2
Spinal Cord Functions:
Centre for many reflex actions Provides a means of
communication between brain and the spinal nerves which leave the spinal cord
Spinal cord structure Contains interneurons Axons of sensory neurons Dendrites of motor neurons Contains both myelinated and
unmyelinated nerve fibres (white and grey matter)
The Brain Conscious brain: cerebrum –
forebrain Responsible for speech, reasoning,
memory and personality Divided into 2 hemispheres: right
and left Each half contains 4 lobes
Frontal lobe Motor control of skeletal muscles Concentration, problem solving,
judgement
Parietal Sensory recognition of
temperature, touch, pain from body surface
Understanding of language Using speech
Temporal Sensory recognition of smell and
hearing Memory of visual scenes, music,
etc.
Occipital Sensory area for sight Combining visual images with past
experiences
Two side of brain The two sides of the brain control motor
functions for opposite sides of the body (ie. Right hemisphere controls left side of body)
Evidenced by people who have had strokes
Both sides are connected by the corpus callosum
Cutting corpus callosum can control seizures in epileptics but lose left-right control
Unconscious brain: everything below cerebrum
Thalamus: Highest part of brain before
cerebrum Receives sensory input from all
parts of the body (except smell) Sorts out incoming stimuli and
sends then to the brain (appropriate regions of)
“gatekeeper”
Hypothalamus Below thalamus Important for homeostasis Controls hunger, sleep, thirst, etc. Controls pituitary gland Neuroendocrine control centre Body temperature Regulates autonomic nervous system
Cerebellum Second largest portion of brain Coordinates muscle movements Maintains balance with help from
inner ear Maintains muscle tone posture
Pons Relay station that passes info
between cerebellum and medulla oblongota
Medulla oblongota Closest to spinal cord Controls heartbeat, breathing and
vasoconstriction (blood pressure) Reflex controls for vomiting,
coughing, sneezing and swallowing Also regulates autonomic NS