Download Nervous System

Nervous System
What is a neuron?
Neuron is a cell

How many neurons are in your nervous
system?
PNS
Peripheral Nervous System
Consist of 2 components
 Sensory neurons
 Motor neurons
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Physiology of PNS

Receives information about an
environmental change, or stimulus.
Examples are the following:
change in temperature
tap on the shoulder
Sensory neurons

Neurons that carry information about
stimuli to the CNS-Central Nervous system
How do sensory neurons detect a
stimuli?

Answer on next slide
Sensory receptors

Most stimuli are received by receptors
located on the membrane of nerve cells.
Integration

When the CNS interprets the information
from sensory neurons, integration takes
place. This step involves neurons located
entirely within the CNS (Brain & Spinal
Cord) and between gray and white matter.

Cells that interpret information are called
interneurons
How do signals or information
transfer to other parts of the body?
Motor Neurons

Neurons that carry such signals away form
the CNS (brain & spinal cord).
Motor neurons target the following:
Cardiac muscle
 Smooth muscle
 Gland to secrete a hormone
e.g. S.A. node of the right atrium
-bundles of nerves that detects blood
pressure
Peristalsis-contraction of the esophagus
Gastrin- a hormone released in the stomach to
aid in digestion

Knee-Jerk Reflex: An Example
Answer the following and place into
composition book
Define the two subdivisions of the nervous
system, and list the nervous system’s
three main function
 Explain how the three types of neurons
are involved in a simple reflex arc.
 Give two examples of environmental
stimuli other than those discussed in the
text.
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