Download Muscles: I. Types a. Skeletal b. Cardiac c. Smooth II. Differ in a. Cell

Muscles:
I.
II.
III.
Types
a. Skeletal
b. Cardiac
c. Smooth
Differ in
a. Cell structure
b. Body location
c. How they are stimulated to contract
Similarities
a. Elongated
i. Reason they are called muscle fibers
b. shorten and contract
c. terminology
i. myo and mys mean muscle
ii. sarco means flesh
IV. Skeletal muscle (terms to remember skeletal, striated
and voluntary)
a. Fibers packed together to make skeletal muscle
b. Attach to the skeleton
c. Cover bones to make contours smooth
d. Fibers are
i. Cigar shaped
ii. Multinucleate
iii. Some up to 1 foot in length
iv. So large they can be seen with the naked eye
1. antigravity muscles
2. example hip
e. known as striated
i. fibers appear striped
f.
g.
h.
i.
ii. only muscle that is under conscious control
can contract with great force
tires very easily
must rest after short periods of activity
bundled together with connective tissue
Endomysium (sheathing on outside of muscle fibers)
Perimysium covering on a group of fibers (several sheathed fibers
wrapped together)
Fibers wrapped together form a fascicle
Bind many fascicles together to with an outer coat called an
epimysium
Bind these together into cordlike tendons or sheet like aponeuorses
--these connect to bones, cartilage or each other.
V.
Smooth muscle (terms to remember….visceral,
nonstriated and involuntary)
a. No striations
b. Involuntary
c. Location
i. Walls of visceral organs
1. stomach
2. urinary bladder
3. respiratory passages
d. propels substances along a tract
e. microscopic
i. spindle-shaped
ii. single nucleus
iii. sheets or layers
1. one circular the other longitudinally
f. can work for long and slow periods
g. take care of “housekeeping” activities
i. move food through digestive tract
ii. force feces out of distal digestive tract
iii. can work tirelessly
VI. Cardiac Muscle (key terms …cardiac, striated,
involuntary)
a. Found only in heart
b. Similar to the other two muscle types
i. Striated like skeletal
ii. Involuntary like smooth
c. found in spiral shapes or figure 8 patterns
VII. Muscle functions
a. Produces movements
b. Maintains posture
c. Stabilizes joints
d. Generates heat