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External
Lobes, Cerebellum and Brain Stem
Frontal lobes
are located right under the forehead. The frontal lobes are
involved in motor function, problem solving, spontaneity,
memory, language, initiation, judgment, impulse control, and
social and sexual behavior.
The left frontal lobe is involved in controlling language
related movement. The right frontal lobe plays a role in nonverbal
abilities.
Parietal lobes
are located near the back and top of the head. The parietal
lobes are involved in location for visual attention, location
for touch perception, goal directed voluntary movements, manipulation
of objects, integration of different senses that allows for
understanding a single concept.
Occipital lobes
are located at the back of the head. The occipital lobes decode
visual information.
Temporal lobes
are located above ears. The temporal lobes are involved in
hearing ability, memory acquisition, some visual perceptions,
categorization of objects.
Cerebellum is
located at the base of the skull. The cerebellum is involved
in coordination of voluntary movement, balance and equilibrium,
some memory for reflex motor acts.
Brain stem is
located deep in brain, leads to spinal cord. The brain stem
is involved in breathing, heart rate, swallowing, reflexes
to seeing and hearing. It controls sweating, blood pressure,
digestion, temperature. It also affects level of alertness,
ability to sleep, sense of balance (vestibular function).
Inside the
Brain (sagittal section)
| Cortex
is the part of the brain that makes human beings so different
from other animal species. It contains 75% of the brain
neurons. It controls sensory and motor functions and uniquely
human functions: language, imagination, planningm reasoning,
consciousness. In addition to its four external lobes,
the cortex also contains a fifth, internal lobe, which
is involved in memory and emotions. |
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| Cingulate
Gyrus adjusts blood pressure, heart rate, pupil
size and other psychosomatic responses that accompany
emotional reactions. |
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| Corpus
Callosum is a thick band of nerve fibres containing
axons through which homologous and non-homologous regions
of the brain's two hemispheres communicate with each other. |
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Hipothalamus
ensures the balance of our internal enviroment
by influencing our hunger, thirst, and sex drive. It manages
the body's internal clock, which affects sleep and body
temperature. It also affects our emotions through pituitary
gland, which is located just below it. The hypothalamus
controls this gland, which produces hormones that regulate
sexual maturation, maternal behaviour, and responses to
stress.
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Thalamus
is the brain's "mixing console". It relays
visual, auditory, taste, and touch onformation to the
cortex and determines which pieces of this information
reach consciousness. The thalamus is involved in exchanges
of motor signals between the cortex, the basal gangliam
and the cerebellum, in pain and attentiveness.
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| Basal
Ganglia are located on either side of the thalamus.
It is involved in initiating and controlling movements
and modulating sensations. The basal ganglia and thalamus
are called "the central grey nuclei". |
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| Amygdala
is located near the hippocampus. It plays a role in learning,
memory, and most of all in the regulation of emotions.
The amygdala are esoecially involved in fear and aggressive
reactions. When the amygdala detects certain potentially
dangerous stimuli, it alert other brain structures that
coordinate the body's fight-or-flight responce. |
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The Ventricular
System
 For
protection, the brain and the spinal cord are bathed in cerebro-spinal
fluid. This fluid circulates through a series of communicating
cavities called ventricles. Cerebro-spinal fluid also circulates
between the pia mater and the arachnoid mater of the meninges.
In addition to cushioning blows, this fluid reduces the pressure
at the base of the brain by causing the nerve tissue to “float”.
Cerebro-spinal fluid is secreted by the choroid plexus in
the upper ventricles and absorbed by the venous system at
the base of the brain. As this fluid flows downward, it carries
away toxic wastes and moves hormones between widely separated
regions of the brain.
References and additional reading
1. www.thebrain.mcgill.ca
2. www.neuroskills.com
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