4
Regions of the Brain
Cerebellum –
coordination of movement and
aspects
of motor learning
Cerebrum –
conscious activity including
perception, emotion, thought, and planning
Thalamus
–
Brain’s switchboard – filters and then
relays information to various brain regions
Medulla
–
vital reflexes as heart beat and respiration
Brainstem –
medulla, pons, and midbrain
(involuntary responses) and relays information from
spine to upper brain
Hypothalamus–
involved in
regulating activities
internal organs, monitoring information from the
autonomic nervous system, controlling the pituitary gland and its hormones, and regulating sleep and
appetite
Cerebrum
•
Is the largest portion of the brain encompasses
about two-thirds of the brain mass -
•
It consists of two hemispheres divided by a
fissure – corpus callosum
•
It includes the cerebral cortex, the medullary
body, and basal ganglia
•
cerebral cortex
is the layer of the brain often
referred to as gray matter because it has cell
bodies and synapses but no myelin
o
The cortex (thin layer of tissue) is gray
because nerves in this area lack the
insulation or white fatty myelin sheath that
makes most other parts of the brain appear
to be white.
o
The cortex covers the outer portion (1.5mm
to 5mm) of the cerebrum and cerebellum
o
The cortex consists of folded bulges called
gyri
that create deep furrows or fissures called
sulci
o
The folds in the brain add to its surface area which increases the amount of gray matter and the
quantity of information that can be processed
•
Medullary body
– is the white matter of the cerebrum and consists of myelinated axons
o
Commisural fibers – conduct impulses between the hemispheres and form corpus
callosum
o
Projection fibers – conduct impulse in and out of the cerebral hemispheres
o
Association fibers – conduct impulses within the hemispheres
•
Basal ganglia
– masses of gray matter in each hemisphere which are involved in the control of
voluntary muscle movements
