Muscle TissueChapter 4

Anatomy and Physiology

Mr. Rick Knowles

Liberty Senior High School

Do you have as many muscle cells as Arnold,

girly man?

Three Types of Muscle Tissue

• Skeletal Muscle Tissue

• Cardiac Muscle Tissue

• Smooth Muscle Tissue

Skeletal Muscle Tissue• Long Cells- also known as muscle

fibers (+ 1 ft in length).

• Have many nuclei (multinucleated).• Unable to divide, but do have

satellite cells (stem cells) that can partially repair damage.

Muscle Cell (Fiber)

Nuclei

SarcoplasmSarcolemma

Skeletal Muscle Tissue• Tissue is Striated- actin and myosin

filaments in cells are arranged, have a banded appearance.

• Contraction stimulated by nerves; voluntary control- Striated Voluntary Muscle.

Skeletal Muscle Tissue

Skeletal Muscle Tissue

Motor End Plate

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are needed to see this picture.

Cardiac Muscle Tissue• Found only in heart.• Is striated.• Cells are smaller than skeletal and

usually one nucleus.• Lack satellite cells-unable to

regenerate.

Cardiac Muscle Tissue• Cells have connections-Intercalated

Discs- cell membranes interlocked by CAMs at desmosomes.

• Also, have gap junctions at these connections.

• What are their functions?

Intercalated Discs

• Desmosomes- keep cells together during contractions.

• Gap Junctions- ion movement between cells coordinate contractions.

Cardiac Muscle Tissue

Cardiac Muscle Tissue

• Do not rely on nerve activity for contraction- have pacemaker cells- involuntary contraction (ANS).

• Also called Striated Involuntary Muscle

So if cardiac muscle can’t regenerate, what happens

after a heart attack?

Can we grow new cardiac cells for the heart?

Movie- Scientific American: Never Say Die

Smooth Muscle Tissue

• Line blood vessels, hollow organs (bladder), respiratory and digestive tracts.

• Cells are small, spindle-shaped with single nucleus.

• Can divide and regenerate.

Smooth Muscle Tissue• No striations.• Contraction part of the ANS,

involuntary.Ex. Peristolsis• Do have gap junctions-coordinate

contractions.• Nonstriated Involuntary Muscle

Smooth Muscle Tissue