Download Nerve Tissue

Chapter 7 Part I The Nervous
System (pp. 202-214)
What effect does the Nervous System
have on you?
What are the three overlapping &
major functions of the Nervous
System?
1. Sensory Input-collects
information from you physical
surroundings (think of your 5
senses)
2. Integration-processing the
information and making a
mental decision on what to do.
3. Motor Output-the actual and
physical response (action and
movement).
How to understand our nervous
system?
• The nervous system is
ONE complex system
• But in order to
simplify and
understand it—it has
been broken down
into divided into it
structure and
function.
Structure of your Nervous System
• It is broken down into two subdivisions
1. The Central Nervous System (CNS)
• The Brain and Spinal Cord
– Integrate the sensory input, then processes and makes
the decision.
2. Peripheral Nervous System (PNS)
•
The nerves that extend from the brain and the
spinal cord. Two types of PNS nerves exist.
1. Spinal nerves carry impulses to and from the
Spine.
2. Cranial Nerves carry impulses to and from
the Brain
• These two systems link all parts of the body by carrying
impulses from the sensory receptors to the CNS and from
there to appropriate glands or muscles.
Structure of your Nervous System
• Also, broken down into two subdivisions
– Sensory (Afferent) division
• Nerve fibers that bring impulses to the CNS from
sensory receptors located throughout the body such as
impulses coming from your skin.
–Motor (Efferent) division-carries impulses from the CNS
and there are 2 components to the Motor division
1. Somatic (voluntary) nervous system-this is were our control of
voluntary functions or conscious actions occur.
2. Autonomic (involuntary) nervous system-this you do not
control but it happens (heart beating/digestion)
Structure of your Nervous System
• Visional representation from previous slide
– Sensory (Afferent) division
–Motor (Efferent) division-
• Tissue by definition is an
area where there are
many cells next to each
other that are the same
type.
• Nerve Tissue is made up
to two types of cells
1. Supporting cells
2. Neurons (nerve cell)
Nerve Tissue
• There are many types of
supporting cells for neurons.
• They are in put into one
group called Neuroglia
(
).
• These support cells function
to protect, insulate, and
protect the neurons.
• They DO NOT transmit nerve
impulses-that is the job of
the neurons (nerve cell).
Nerve Tissue
• Specialize in transmitting
message from one part of
the body to the another.
• There are differently
structured neurons BUT no
matter what they all have
two things in common:
– A cell body with a nucleus
– One or more “branches”
coming out of the cell body.
Nerve Tissue
– Occur over neural pathways
called
– One of the forms of
communication that neurons
must do DAILY (create reflexes)
– Reflexes are rapid, predictable,
and involuntary responses to
stimuli.
– Travel only in one direction (one
way only) once they start.
Nerve Tissue
– Reflexes are classification into two classes:
• Autonomic Reflexes
– Involuntary
» Regulate the activity of smooth muscles, heart,
glands, secretion of saliva, changes sizes of eye
pupils, digestion, elimination (pooping),
regulates blood pressure, and sweating
• Somatic Reflexes
– Voluntary
» Includes all reflexes that stimulate the skeletal
muscles. Pulling your hand away from a hot
object you picked up is an example of Somatic
Reflexes.
Nerve Tissue
All reflexes work off of the “Reflex Arc” concept
•
All Reflex Arcs have a minimum of five elements.
1.
2.
3.
4.
5.
Receptor
Sensory neuron
Integration center
Motor neurons
Effector
Be prepared for Exam on Tuesday
• Study and understand the material.