CNS: Spinal Cord Function

• Communication between the Brain and the PNS.• Example: hand touched sensory fibers

generate nerve impulses passes through sensory neurons spinal cord ascending tract brain.

• Center for reflex arcs. A stimulus causes sensory receptors to generate nerve impulses through sensory nerves these go to interneurons that integrate the data and respond.

CNS - Brain

• The brain is organized in ventricles. The Cerebrum is in the two lateral ventricles, the diencephalon is in the third ventricle, and the brain stem is in the fourth ventricle.

• Cerebrum: largest portion; last to receive sensory input and integrate it before commanding voluntary motor response; coordinates other areas of the brain; and carries out higher thought processes, memory, language, speech, and learning.

More Brain

• Diencephalon: hypothalamus, thalamus and the pineal gland. Thalamus receives all sensory input except smell. This area integrates this information and sends it to the appropriate area of the cerebrum.

• Cerebellum: Receives sensory input from the eyes, ears, joints, and muscles about the position of body parts. It also receives information from the cerebral cortex as to where those parts should be located. Therefore it plays a role in posture, balance, and coordination.

Even More Brain

• Brain stem: contains the midbrain, the pons, and the medulla oblongata.

Midbrain – relay station for tracts

Pons – contains bundles of axons traveling between the cerebellum and the rest of the CNS.

Medulla Oblongata - contains a lot of reflex centers for controlling heartbeat, breathing, and vasoconstriction.

Brain Mapping Activity

• You will be provided with three diagrams of the brain. The image of the brain is a lateral view including the brain stem. On the other side you will see A) a posterio-lateral external view and B) a cross-section of a lateral view.

• Identify, label and differentiate with color the lobes on all 3 diagrams.

• Label the parts of the brain stem and include a brief description of their functions on the image of the brain.

• Identify the different areas of the brain and the limbic system on A and B (see pp. 148 and 149).