Title: Muscle Structure and Function
1Muscle Structure and Function
2Muscle Types
- Skeletal Muscle
- Primarily links to bone through tendon
- Enabling through levers of the bones of the human
skeleton, allows for posturing, upright stance
under atmospheric pressure, and voluntary
movements. - Heat production- 85 of body heat is generated by
muscles providing the proper environment for
enzymes and therefore metabolism
3Muscle Types
- Smooth Muscle
- Found in parts of the body where it conveys
action without conscious intent. - Majority of this type of muscle tissue is found
in the Digestive and Urinary systems where it
acts by propelling forward food and feces - Other places smooth muscle can be found are
within the uterus, where it helps facilitate
birth, and the eye, where the pupillary sphincter
controls pupil size. - Cardiac Muscle
- Specific to the heart.
- Involuntary in its movement, and is additionally
self-excitatory, contracting without outside
stimuli.
4Characteristics of all Muscle
- Excitability
- Respond to stimuli
- Contractility
- Actively shorten to exert a pull
- Extensibility
- Continue to contract over range of resting
lengths - Ex smooth muscle can be stretched to several
times its original length and still contract on
stimulation - Elasticity
- Return to original length after contraction
5Location
Function
Frontalis Frontal bone
Femoris Femur
Gluteus Posterior of hip/thigh
Oculi Eye
Oris Mouth
Radialis Radius
Ulnaris Ulna
Brachialis Arm
Abductor Moves part away from body
Adductor Moves part toward body
Depressor Lowers a part
Extensor Extends a part
Flexor Flexes a part
Levator Elevates a part
Rotator Rotates a part
Shape
Fiber Direction
Deltoid Shaped like delta ?
Orbicularis Circular
Platy Flattened platelike
Quadratus Square
Rhomboideus Diamond-shaped
Trapezius Trapezoidal
Oblique Diagonal to midline
Rectus Parallel to midline
Sphincter Circling an opening
Transversus Right angle to midline
6Number of divisions
Bicep Two heads
Tricep Three heads
Quadricep Four heads
Size
Brevis Short
Longus Long
Magnus Large
Maximus Largest
Medius Moderately sized
Minimus Smaller
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8Structures of a skeletal muscle fiber
9Sarcomere The repeating patterns formed in
muscle striations
Sacromere
Z Line
H Zone
M Line
I Band
A Band
10Muscle Fiber Arrangement
Parallel
Pennate
Bipennate
Sphincter
Convergent