Muscular and Nervous Tissue

Chapter 4.3

Human Anatomy & Physiology

Muscular Tissue

• Function• Contraction• Attachment by

tendons to bones for movement

• Movement: Voluntary and involuntary

Muscular Tissue

• Appearance – striated (striped) – Alternating light and

dark bands

• Location – Usually attached to skeleton

• Each cell has a nucleus that is centrally located

Types of Muscular Tissue

• Types

A. Skeletal

B. Smooth

C. Cardiac

Characteristics of Skeletal Muscle

• Appearance: striated

• 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, urinary bladder, blood vessels

• Control: Involuntary • Contracts rhythmically and

quickly, tires easily (fatigable)• Allows for wide range of

forces to be generated

Smooth Muscle

Smooth Muscle Tissue - 400X

Cardiac Muscle

• Has features of both skeletal and smooth muscle- Strong contractions and striated appearance is similar to skeletal muscle- Involuntary control and rhythmic contraction is similar to smooth muscle

• Appearance: striated and branched (like skeletal muscle)

• Location: heart• Function: contraction

of heart pumps blood and causes the heartbeat

• Control: Involuntary (like smooth muscle)

Cardiac Muscle Tissue - 400X

Nervous Tissue

• The ultimate control of all the organ systems is done by the nervous system.– The nervous system controls and coordinates

functions throughout the body and responds to internal and external stimuli.

Nervous Tissue

• Found: brain, spinal cord, has specialized cells

• The cells that transmit these impulses are called neurons.

Structure of a Neuron

Axon terminals

Myelin sheath

Cell body

Nodes Axon

Dendrites

Nucleus

Neuron Structure

• The largest part of a typical neuron is the cell body.

• It contains the nucleus and much of the cytoplasm.

Neuron Structure

• Dendrites extend from the cell body and carry impulses from the environment toward the cell body.

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.