Basic Structure and Function of the Nervous System | Unit 3: Regulation, Integration, and Control

Описание

The nervous system can be separated into divisions on the basis of anatomy and

physiology. The anatomical divisions are the central and peripheral nervous systems. The
CNS is the brain and spinal cord. The PNS is everything else. Functionally, the nervous
system can be divided into those regions that are responsible for sensation, those that
are responsible for integration, and those that are responsible for generating responses.
All of these functional areas are found in both the central and peripheral
anatomy.


Considering the anatomical regions of the nervous system, there are specific
names for the structures within each division. A localized collection of neuron cell
bodies is referred to as a nucleus in the CNS and as a ganglion in the PNS. A bundle of
axons is referred to as a tract in the CNS and as a nerve in the PNS. Whereas nuclei and
ganglia are specifically in the central or peripheral divisions, axons can cross the
boundary between the two. A single axon can be part of a nerve and a tract. The name for
that specific structure depends on its location.


Nervous tissue can also be described as
gray matter and white matter on the basis of its appearance in unstained tissue. These
descriptions are more often used in the CNS. Gray matter is where nuclei are found and
white matter is where tracts are found. In the PNS, ganglia are basically gray matter and
nerves are white matter.


The nervous system can also be divided on the basis of how it
controls the body. The somatic nervous system (SNS) is responsible for functions that
result in moving skeletal muscles. Any sensory or integrative functions that result in
the movement of skeletal muscle would be considered somatic. The autonomic nervous system
(ANS) is responsible for functions that affect cardiac or smooth muscle tissue, or that
cause glands to produce their secretions. Autonomic functions are distributed between
central and peripheral regions of the nervous system. The sensations that lead to
autonomic functions can be the same sensations that are part of initiating somatic
responses. Somatic and autonomic integrative functions may overlap as well.


A special division of the nervous system is the enteric nervous system, which is responsible for
controlling the digestive organs. Parts of the autonomic nervous system overlap with the
enteric nervous system. The enteric nervous system is exclusively found in the periphery
because it is the nervous tissue in the organs of the digestive system.






00:00 Basic Structure and Function of the Nervous System
01:01 The central and peripheral nervous systems
08:03 Functional divisions of the nervous system
09:40 Basic functions
14:14 Controlling the body
17:14 Everyday connection
19:58 Chapter review




Attribution: OpenStax, Anatomy & Physiology Book
https://openstax.org/books/anatomy-and-physiology