Page 59 - 84 human physiolofy part-1

The Nervous System

Brain

The brain is found in the cranial
cavity. Within it are found the higher nerve
centers responsible for coordinating the
sensory and motor systems of the body
(forebrain). The brain stem houses the
lower nerve centers (consisting of
midbrain, pons, and medulla),

Medulla

The medulla is the control center for
respiratory, cardiovascular and digestive A color-coated image of the brain, showing the main sections.
functions.

Pons

The pons houses the control centers for respiration and inhibitory functions. Here it will interact
with the cerebellum.

Cerebrum

The cerebrum, or top portion of the brain, is divided by a deep crevice, called the longitudinal
sulcus. The longitudinal sulcus separates the cerebrum in to the right and left hemispheres. In the
hemispheres you will find the cerebral cortex, basal ganglia and the limbic system. The two
hemispheres are connected by a bundle of nerve fibers called the corpus callosum. The right
hemisphere is responsible for the left side of the body while the opposite is true of the left hemisphere.
Each of the two hemispheres are divided into four separated lobes: the frontal in control of specialized
motor control, learning,planning and speech; parietal in control of somatic sensory functions; occipital
in 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. 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.

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