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Muscular and Nervous Tissue
Chapter 4.3
Human Anatomy & Physiology
Muscular Tissue
• Function
• Contracts to produce
movement
• Movement can be
voluntary or
involuntary
Types of Muscular Tissue
• 3 Types
1. Skeletal
2. Smooth
3. Cardiac
Characteristics of Skeletal Muscle
• Appearance: striated
(striped) and column-shaped
cells (muscle fibers)
– Alternating light and dark bands
make striations
• Location: Attached primarily
to bones
• Control: Voluntary
(conscious)
• Contracts quickly, tires easily
(fatigable)
• Allows for wide range of
forces to be generated
Skeletal Muscle Tissue - 400X
Smooth Muscle
• Appearance: spindleshaped
• Location: wall of hollow
organs
– example: Intestines, urinary
bladder, ureters, blood vessels
• Control: Involuntary
• Contracts rhythmically and
quickly
Smooth Muscle
Smooth Muscle Tissue - 400X
Cardiac Muscle
• Has features of both skeletal and smooth muscle
- Like skeletal muscle, it has strong contractions
and striated appearance
- Like smooth muscle, it is under involuntary
control and has rhythmic contraction
• Appearance: striated
and branched
• Location: heart
• Function: contraction
of heart pumps blood
and causes the
heartbeat
• Control: Involuntary
Cardiac Muscle Tissue - 400X
Nervous Tissue
• The ultimate control of all the organ
systems is done by the nervous system.
– Function: controls and coordinates all bodily
functions and responds to internal and
external stimuli.
THINK…
COMMUNICATION!
Nervous Tissue
• Found: brain, spinal
cord, and peripheral
nerves
• The cells that transmit
messages (impulses)
are called neurons.
Structure of a Neuron
Nucleus
Dendrites
Axon
terminals
Cell body
Myelin sheath
Nodes
Axon
Neuron Structure
• Dendrites extend from the cell body and
carry impulses from the environment
toward the cell body.
Neuron Structure
• The largest part of a typical neuron is the
cell body.
• It contains the nucleus and much of the
cytoplasm.
Neuron Structure
• The axon is the long fiber that carries
impulses away from the cell body.
Neuron Structure
• The axon is sometimes surrounded by an
insulating membrane called the myelin
sheath.
Neuron Structure
There are gaps in the myelin sheath, called
nodes, where the membrane is exposed.
• Impulses jump from one node to the next.
Neuron Structure
Impulses are then passed to the next cell by
the axon terminals.