Human Physiology/The Nervous System

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control of vision; and temporal lobes which consists of hearing centers and some speech. Located deep to the

temporal lobe of the cerebrum is the insula.

Cerebellum

The cerebellum is the part of the brain that is located posterior to the medulla oblongata and pons. It coordinates

skeletal muscles to produce smooth, graceful motions. The cerebellum receives information from our eyes, ears,

muscles, and joints about what position our body is currently in (proprioception). It also receives output from the

cerebral cortex about where these parts should be. After processing this information, the cerebellum sends motor

impulses from the brainstem to the skeletal muscles. The main function of the cerebellum is coordination. The

cerebellum is also responsible for balance and posture. It also assists us when we are learning a new motor skill, such

as playing a sport or musical instrument. Recent research shows that apart from motor functions cerebellum also has

some emotional role.

The Limbic System and Higher Mental Functions

Image of the brain, showing the Limbic system.

The Limbic System

The Limbic System is a complex set of structures found just beneath

the cerebrum and on both sides of the thalamus. It combines higher

mental functions, and primitive emotion, into one system. It is often

referred to as the emotional nervous system. It is not only responsible

for our emotional lives, but also our higher mental functions, such as

learning and formation of memories. The Limbic system explains why

some things seem so pleasurable to us, such as eating and why some

medical conditions are caused by mental stress, such as high blood

pressure. There are two significant structures within the limbic system

and several smaller structures that are important as well. They are:

1. The Hippocampus

2. The Amygdala

3. The Thalamus

4. The Hypothalamus

5. The Fornix and Parahippocampus

6. The Cingulate Gyrus

Structures of the Limbic System

Hippocampus

The Hippocampus is found deep in the temporal lobe, shaped like a seahorse. It consists of two horns that

curve back from the amygdala. It is situated in the brain so as to make the prefrontal area aware of our past

experiences stored in that area. The prefrontal area of the brain consults this structure to use memories to

modify our behavior. The hippocampus is responsible for memory.

Amygdala

The Amygdala is a little almond shaped structure, deep inside the anteroinferior region of the temporal lobe,

connects with the hippocampus, the septi nuclei, the prefrontal area and the medial dorsal nucleus of the

thalamus. These connections make it possible for the amygdala to play its important role on the mediation and

control of such activities and feelings as love, friendship, affection, and expression of mood. The amygdala is