The spinal cord, a rope of neural tissue inside the vertebrae, responds to sensory inputs and directs
muscle responses. It is composed of 2 distinct tissue types: gray matter (dominated by the cell bodies of
neurons) and white matter (consists mostly of axons and the fatty sheaths that surround them)
The brainstem houses the basic programs of survival including breathing, swallowing, vomiting,
urination, and orgasm.
The two brain structures in this area are the reticular formation (implicated in attention and arousal)
and the cerebellum (involved with initiation and motor movement)
The limbic system is a subcortical region involved with basic drives and emotion. The limbic system
includes the hypothalamus (eating, drinking, body temperature), the thalamus (relays sensory
information), hippocampus (formation of new memories), and the amygdala (processing new strong
emotional information). The basal ganglia are another system of subcortical structures crucial for
planning and producing movements. Almost all sensory information must go through the thalamus in
the limbic system before reaching the cortex (exception being sense of smell which has a direct route).
Changes in neuronal connections occur as a result of experience. Neurons that fire together strengthen
their connections with one another, increasing the likelihood that they will fire together in the future, a
process known as Hebbian learning. t cells that fire together, wire together
It appears that the left hemisphere is highly involved in the functions of speech and language. The left
hemisphere also has a propensity to try and make sense out of the world even when the data does not
make sense. The right hemisphere seems to be more involved with spatial relationships and emotional
The spinal cord is a rope of neural tissue that runs inside the vertebrae from just above the pelvis to the
base of the skull.
The reticular formation is a large network of neural tissue within the brainstem involved in behavioral
arousal and sleep-wake cycles.
The pituitary gland is controlled by the hypothalamus.
The cerebral cortex is the thin outer layer of brain tissue that forms the convoluted surface of the brain.
The cerebral cortex underlies most complex mental activity. The cortex Is divided into four regions
called lobes. The occipital lobe is most exclusively devoted to vision and is the home of the primary
visual cortex. The parietal lobe is devoted to the sense of touch and the spatial layout of the
environment. The temporal lobe is taken up with the primary auditory cortex as well as some of the
auditory aspects of memory. Finally the frontal lobe is the one that makes us seem most human
because it is involved with planning, empathy and making choices.
The prefrontal cortex is a region in the frontal lobes that is important for attention, working memory,
decision making, appropriate social behavior and personality.