Human Anatomy Lesson 1

Muscular Systems

The Muscular System​

Muscles are responsible for all types of body movement​

There are three basic muscle types:

• Skeletal Muscle

• Cardiac Muscle

• Smooth Muscle​

​Cardiac Muscle is HEART MUSCLE

Cardiac Muscle Cells:​

• ​Usually have a single nucleus

• ​Are joined to other muscle cells at intercalated discs

• Function Involuntarily

• Are found ONLY in the heart​

• Have striations- repeating bands/grooves

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Cardiac Muscle​

Open Ended

Discuss with your group: Why is it important that Cardiac Muscle function Involuntarily?

Smooth Muscle​

Smooth Muscle Cells exist in our gut, stomach, and other hollow organs​

Smooth Muscle Cells:

• Have no striations

• ​Are spindle shaped

• Have a single nucleus

• Function Involuntarily​

Some text here about the topic of discussion

Skeletal Muscle​

Skeletal Muscles are what most of us think about when we think of muscles ​

• Most are attached by tendons and bones

• Cells are multinucleate

• Striated​- visible banding

• Voluntary- subject to conscious control

​Skeletal muscle cells are surrounded and bundled together by connective tissue

Open Ended

Discuss with your group: What do muscles do?

Muscles have Four basic functions:​

• Produce Movement

• Maintain Posture

• ​Stabilize Joints

• Produce Heat​

Endomysium:​ Wraps around a single muscle fiber (myofiber)

​Perimysium: Wraps around a bundle of fibers, called a Fascicle

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​Connective Tissue Wraps Around Skeletal Muscles!

Epimysium: Surrounds the entire skeletal muscle

​

​Fascia: the outer layer of the epimysium

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MORE CONNECTIVE TISSUE!​

​

• Bone​s

• Cartilage

• ​Connective Tissue Coverings

Sites of Connective Tissue Attachment​

​Tendon- Cord-like structures

Aponeuorses​- Sheet-like structures

​

Epimysium blends into a ​connective tissue attachment

Multiple Choice

True or False: Cardiac muscle is Multinucleate

• True

• False

Multiple Choice

Which of the following is NOT one of the basic functions of Muscles

• Produces Heat

• Produces Movement

• Supports Joints

• Defends the Organs

Multiple Choice

Endomysium is wrapped around...

• the Epimysium

• a single muscle fiber

• a collection of muscle fibers

• the Perimysium

Multiple Choice

Which type of muscle is NOT striated

• Skeletal Muscle

• Cardiac Muscle

• Smooth Muscle

• Rough Muscle

Multiple Choice

A bundle of muscle fibers is called a...

• Fascicle

• Epimysium

• Striation

• Tendon