1. Muscular System Part 1
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2. Muscle Functions
Movement of bones or fluids (e.g., blood)
Maintaining posture and body position
Stabilizing joints
Heat generation (especially skeletal muscle)
arrector pili muscles-hairs stand up-insulate body

5. Smooth Muscle

7. Cardiac Muscle

8. Characteristics of Muscle Tissue
Excitability (responsiveness or irritability): ability to receive and respond to stimuli
Contractility: ability to shorten when stimulated
Extensibility: ability to be stretched
Elasticity: ability to recoil to resting length
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9. Levels of Organization
Insertion/Origin
Attachments
Tendons & aponeurosis
tissue that covers & forms the terminations and attachments of various muscles
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10. Origin and Insertion
Origin: immovable end of muscle Insertion: movable end of muscle **when a muscle contracts the insertion is moved toward the origin
The biceps brachii has two origins (or two heads).

11. When muscles attach to bones one end becomes Origin and the other becomes Insertion
Point of attachment that connects to a stationary bone
Insertion
Point of attachment on the moving bone

12. Skeletal muscles work in groups
Terms describing roles of muscles carrying out actions:
Agonist: (prime mover) muscle that causes an action
Antagonist: muscle that works against the action
Synergists: muscles that contribute to an action by helping the agonist.
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13. Most common types of movement
Flexion: decreases the angle of the joint and brings two bones closer together (bending knee or elbow; bending forward at hip)
Extension: opposite of flexion; increases the angle or distance between two bones (straitening knee or elbow)
Rotation: movement of a bone around its longitudinal axis (ball & socket joints; shaking your head “no”)
Abduction: moving a limb away from the midline; also applies to fanning movement of fingers and toes
Adduction: opposite of abduction; limbs moves toward the midline
Circumduction: combination of flexion, extension, abduction, and adduction; movement in a cone-shaped pattern (rotating around at shoulder)

14. Flexion
You will need to know the action or movement performed for each of the muscles we study. The first type of movement is called flexion. Note the lower leg is being flexed in this diagram. During flexion the angle of joint is decreased. As the knee is flexed, the angle between the lower leg and the thigh is decreased. Flexion of the upper arm is also illustrated in this diagram. Here the angle between the arm and the frontal plane is decreased.

15. Extension
Extension is the opposite of flexion. In extension the angle of a joint is increased. Extension of the lower leg causes an increased angle between the lower leg and the thigh.

16. Hyperextension
Flexion and extension also apply to the neck. When a joint is extended past the anatomical position the movement is called hyperextension.

17. Abduction, Adduction & Circumduction
Abduction refers to moving away from the median plane of the body. Adduction is the opposite movement to abduction. It is moving toward the medial plane. Circumduction refers to inscribing a circle while moving a limb.

18. Rotation
Rotation is turning a bone on its own axis. Moving the head back and forth to indicate “no” is an example of rotation. Note the difference between medial and lateral rotation. In lateral rotation the limb is rotated the lateral side of the body. Medial rotation rotates the limb toward the medial side of the body.

19. Muscle Attachment Tendon Strong connective tissue
Attaches muscle to bone
Achilles Tendon which attaches Gastrocnemius muscle of the calf to the heel

20. Muscle Attachment Fascia Tough sheet-like connective tissue
Covers & protects muscle tissue
Lumbodorsal Fascia-surrounds deep muscle of the back

21. Skeletal muscle anatomy
Epimysium: a tougher overcoat of connective tissue which wraps many fascicles together
Tendons: strong cord- like bundles of the blended epimysia
Aponeuroses: sheet-like bundles which attach muscle indirectly to bones, cartilage, or connective tissue coverings of each other

22. Skeletal muscle anatomy
Perimysium: more coarse fibrous membrane that wraps several sheathed muscle fibers
Endomysium: delicate connective tissue sheath which encloses each muscle fiber
Fascicle: the bundle of muscle fibers

23. Connective Tissue Components
Fascia--thin sheets of fibrous connective tissue that hold muscle fibers together
Epimysium--fascia that surrounds the entire muscle
Perimysium--separates muscles into bundles (10 to 100 muscle fibers)
Endomysium--fascia that surrounds each muscle fiber
Tendon—a cord of dense regular connective tissue composed of collagen that attaches muscle to periosteum to bone
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24. Table 9.1

25. Connective tissue wrappings of skeletal muscle
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26. Nerve and Blood Supply Supplied w/ nerves and blood vessels
Related directly to muscle contractions
Utilizes a great deal of ATP
Large amounts of nutrients and oxygen required
An artery and 1 or 2 veins accompany each nerve
Within the endomysium, capillaries are found in each muscle fiber
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