The Central Nervous System The Brain The Spinal Cord

Regions of the Brain The brain is the largest and most complex mass of nervous tissue in the human body. It is protected by cerebrospinal fluid and meninges.

The brain is composed of four major regions: Cerebrum (2 hemispheres) Diencephalon Brain stem Cerebellum

The Cerebral Hemispheres The largest portion of the brain. Is divided into left and right halves. Each lobe is responsible for specific functions. The 2 hemispheres enclose and protect the brain stem.

Each hemisphere of the brain is further divided into 4 areas: frontal lobe parietal lobe occipital lobe temporal lobe

The Frontal Lobe The primary movement area. It controls body areas that have fine motor control: face, mouth, and hands. Allows conscious movement of skeletal muscles. Allows word selection and word articulation. (only left) This is where we interpret taste. Stores memories.

The Parietal Lobe The primary sensory area. Allows us to recognize pain, temperature, or a light touch. The left side of the parietal lobe receives impulses from the right side of the body, and visa versa.

The Occipital Lobe Is the visual area of the brain. Allows us to interpret what we “see”. Receives impulses from the optic nerve.

The Temporal Lobe The auditory area of the brain. Allows us to interpret the sound waves that are directed into the ear. The olfactory area of the brain. An area deep inside the temporal lobe functions to interpret odors detected by the nose. Stores memories.

The junction of the temporal, parietal, and occipital lobes is known as the speech area. This is the area that allows us to comprehend words and is different from the frontal lobe speech area that allows us to select words.

Food for thought… The right side of the brain is said to be associated with creativity and spatial relations. The left side of the brain is more associated with analytical thinking and figuring things out in sequential order. Both sides are connected and switch off and on as necessary.

The Diencephalon Known as the innerbrain, it is sandwiched between the 2 cerebral hemispheres and it sits on top of the brain stem. It is made up of two important parts: The thalamus The hypothalamus cerebrum thalamus cerebellum hypothalamus

The thalamus = determines which lobe of the cerebrum receives the incoming signals. The hypothalamus = regulates body temperature, water balance, appetite and emotions. Certain medications are designed to affect the hypothalamus. Can you ID any?

The Brain Stem Made up of three structures: the midbrain the pons the medulla oblongata

The brain stem provides a pathway for incoming and outgoing signals to the brain. The medulla oblongata also regulates vital activities: heart rate, breathing, and blood pressure.

The Cerebellum A large projection inferior to the occipital lobe of the cerebrum. It also has two hemispheres that control the timing associated with body movements.

It is connected by nerves to the inner ear and to the eye It is connected by nerves to the inner ear and to the eye. As a result, it controls our balance and equilibrium.

The Spinal Cord

There are 31 pairs of spinal nerves: The spinal cord forms from the brain stem and continues down to the 2nd lumbar vertebrae where it becomes nerve endings. There are 31 pairs of spinal nerves: C1 – C8 T1 – T12 L1 – L5 S1 – S5 Coccygeal nerve

The nerves are surrounded by cerebrospinal fluid and is also protected by meninges. They conduct information both to and from the brain.