The Hippocampus is a part of the brain located inside the temporal lobe (humans and other
mammals have two hippocampi, one in each side of the brain). It forms a part of the limbic system
and plays a part in memory and spatial navigation. In Alzheimer’s disease, the hippocampus becomes
one of the first regions of the brain to suffer damage; memory problems and disorientation are
amongst the first symptoms. Damage to the hippocampus can also result from oxygen starvation
(anoxia) and encephalitis.
The Limbic System is not a structure, but a series of nerve pathways incorporating structures
deep within the temporal lobes, such as the hippocampus and the amygdale. It is involved in the
control and expression of mood and emotion, in the processing and storage of recent memory, and
in the control of appetite and emotional responses to food.
The Olfactory Bulb is a structure of the vertebrate forebrain involved in olfaction, the
perception of odors. Odor information is easily stored in the long term memory and has strong
connections to emotional memory. This is possibly due to the olfactory system’s close anatomical
ties to the limbic system and hippocampus, areas of the brain that have long been known to be
involved in emotion and place memory, respectively.
The Thalamus and Hypothalamus are prominent internal structures. The thalmus has wide-
ranging connections with the cortex, and many other parts of the brain, such as the basal ganglia,
hypothalmus and brainstem. It is capable of perceiving pain but not at accurately locating it. The
hypothalamus has several important functions, including control of the body’s appetite, sleep
patterns, sexual drive and response to anxiety.
Anterior Cingulate Cortex (ACC) is the frontal part of the cingulated cortex. The ACC
forms a collar around the corpus callosum, which relays neural signals between the right and left
hemispheres. It appears to play a role in a wide variety of autonomic functions, such as regulating
heart rate and blood pressure, and is vital to cognitive functions, such as reward anticipation,
decision-making, empathy and emotion.
The Spinal Cord
The spinal cord extends from the medulla oblongata in the brain and continues to the conus
medullaris near the lumbar level at L1-2, terminating in a fibrous extension known as the filum
terminale. The adult spinal cord is approximately 18 inches long, ovoid-shaped, and is enlarged in
the cervical and lumbar regions.
The spinal cord conducts sensory information from the PNS to the brain using ascending
pathways called afferent pathways. Using descending pathways called efferent pathways, the
brain sends information through the spinal cord to the specific areas that need be affected. These
efferent pathways typically carry motor information from the brain to our various target sites. The
target sites are skeletal muscles, smooth muscles, cardiac muscles, and glands.