muscular and nervous tissue chapter 3 human anatomy & physiology
TRANSCRIPT
Muscular and Nervous Tissue
Chapter 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: spindle-
shaped• 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
Axon terminals
Myelin sheath
Cell body
Nodes Axon
Dendrites
Nucleus
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.