Component
|
Function(s)
|
Structure
|
|
Cerebellum
|
|
Long Term Memory |
|
Co-ordination (e.g. balance) |
|
Muscle Tone |
|
Movement |
|
Posture |
|
Maintenance of muscle tone, balance,
and the synchronization of activity in groups of
muscles under voluntary
control, converting muscular contractions into
smooth coordinated movement.
However, it does not initiate
movement
and plays no part in the perception of conscious
sensations or in intelligence. |
|
The cerebellum is the largest part of
the hindbrain.
It
bulges back behind the pons varolii and the
medulla
oblongata,
and
is overhung by the occipital lobes of the cerebrum.
Like the cerebrum,
it has an outer grey cortex and a core of white matter.
The cecbellum has three
broad bands of nerve fibres – the inferior, middle,
and superior cerebellar peduncles – which connect
it to the medulla, the pons varolii, and the midbrain
respectively.
|
|
Cerebrospinal Fluid (CSF)
|
|
Bathes the brain and spinal cord |
|
Allows nutrients and waste products to diffuse
between the blood and the brain/spinal cord. |
|
Protects the nerves against mechanical damage |
Cerebrospinal fluid is also the
subject of
cranio-sacral therapy, which is a huge subject
in it's own right. |
|
A clear watery fluid whose normal contents include
glucose, salts, enzymes, and some white blood cells
(but no red blood cells).
This fluid moves within its cavity, typically beating
at 6-12 beats per minute, though this can rise to 12-50
beats per minute (such as in the case of a person who
has a "pulsating" headache). |
|
Cerebrum
|
The Cerebrum is also known as the Cortex
(Cortex = Cerebrum), and is the largest and most highly
developed part of the brain.
This is the ‘learning’ part
of the brain, and the seat of all intelligent behaviour.
It
is responsible for the initiation and coordination
of all voluntary activity in the body and for governing
the functioning of lower parts of the nervous system. |
The cerebrum is composed of two
hemispheres separated from each other by the longitudinal
fissure in the midline. |
|
Each hemisphere has an outer layer of grey matter, the cerebral cortex, below
which lies white matter containing the basal ganglia. Nerves of the cortex
are arranged on the outside surfaces as grey matter. |
|
The corpus collosum is a massive
bundle of nerve fibers that connect the two hemispheres
- at the
bottom of the longitudinal fissure.
|
|
|
Hypothalamus
|
The Hypothalamus is the "Receptor
Centre", and "Control Centre" of the body. |
|
It
contains several important centers controlling
body temperature and eating, and water balance.
Examples include osmo-receptors that balance water/salt
levels and
control the water content of the blood.
(See diagram opposite.) |
|
It is also the Saiety Center (that
is concerned with "satisfaction"), for things
like hunger, thirst, sex. |
|
It is also closely connected with
emotional activity and sleep, and it functions
as a center for the integration of hormonal and
autonomic nervous activity through its control
of the pituitary secretions. |
|
The posterior lobe of the pituitary
secrets two hormones: |
|
A.D.H. (Anti-diuretic hormone, as known
as vasopressin – in U.S.)
This works on the
kidney tubules. Secretion of ADH tells the kidneys
to re-absorb more water, resulting in more concentrated
urine. Non-secretion of ADH results in more peeing,
and weaker urine. |
|
Oxytocin. |
|
The region of the forebrain in the floor of
the third ventricle, linked with the thalamus above
and the pituitary gland below. |
|
|
|
Medulla Oblongata
|
The functions of the medulla oblongata
concern the body's involuntary processes, such
as: |
|
Breathing; |
|
Heart-rate; |
|
Swallowing; |
|
Salivation; |
|
Vomiting; |
|
Blinking. |
|
The cranial nerves VI – XII
leave the brain in this region. |
|
The medulla oblongata is the extension
within the skull of the upper end of the spinal cord,
forming
the lowest
part
of the brainstem. |
|
The Meninges
|
Mechanical protection of the Brain and Spinal column. |
The meninges consist of three parts, the dura
mater, the arachnoid mater, and the
pia mater.
The structures of these are mentioned below.
|
|
Meninges -
Dura
Mater
|
Outermost layer of mechanical protection of the
Brain and Spinal column. |
The outer-most layer of the meninges is inelastic,
tough, and thicker than the other two layers. |
|
Meninges -
Arachnoid Mater
|
Middle layer of mechanical protection of the Brain
and Spinal column. |
The inner two membranes are together called
the leptomeninges; between them circulates the cerebrospinal
fluid. |
|
Meninges -
Pia Mater
|
Innermost layer of mechanical protection of the
Brain and Spinal column. |
|
Pons Varolii
|
The pons varolii is the part of the
brainstem that links the medulla oblongata with the
thalamus. |
Contains numerous nerve tracts between
the cerebral cortex and the spinal cord, and several
nuclei of grey matter.
(The trigeminal nerves emerge from the front surface of
the pons varolii.)
|
This
is the end of this article but further information about
related
topis see the links at the top of this page. 
