Transcript CNS: Spinal Cord Function

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).