Download Skeletal muscle.

Muscular
System
Unit F
Muscle Anatomy
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Nearly half our weight comes from muscle
tissue.
There are 650 different muscles in the human
body.
Muscles give us shape and form.
Muscles produce most of our body heat.
Skeletal muscle.
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Attached to bone.
Striated (striped) appearance.
Voluntary.
Multinucleated muscle cell bundles (muscle cells =
muscle fibers).
Sarcolemma = cell membrane.
Contract quickly, fatigue easily, can’t maintain
contraction or long period of time.
Smooth muscle.
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Visceral (organ) muscle.
Found in walls of digestive system, uterus and blood
vessels.
Cells small and spindle-shaped.
Involuntary.
Controlled by autonomic nervous system.
Act slowly, do not tire easily, can remain contracted for
long time.
Cardiac muscle.
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Found only in the
heart.
Striated and
branched.
Involuntary.
Cells are fusedwhen one contracts,
they all contract.
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Special circular
muscles in
openings of
esophagus and
stomach, stomach
and small intestine,
anus, urethra and
mouth.
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Contractibility- the ability of a muscle to reduce
the distance between the parts of its contents or
the space it surrounds.
Excitability (irritability)- the ability to respond
to certain stimuli by producing impulses.
Extensibility- the ability to be stretched.
Elasticity- ability of muscle to return to its
original length when relaxing.
1.
Muscles move bones by pulling on them.
As a muscle contracts, it pulls the insertion bone
closer to the origin bone. Movement occurs at the
joint between the origin and the insertion.
Rule: A muscle’s insertion bone moves toward its
origin bone.
2. Groups of muscles usually contract to produce a
single movement.
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Motor unit- a motor neuron plus all the
muscle fibers it stimulates.
Neuromuscular junction- the junction
between the motor neuron’s fiber which
transmits the impulse-and the muscle cell
membrane.
Acetycholine- chemical neurotransmitter,
diffuses across the synaptic cleft (carries
impulse across synaptic cleft).
Muscle fatigue- caused by the accumulation
of lactic acid in the muscles.
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Oxygen debt- after exercise, the amount of
oxygen needed by the muscle to change lactic
acid back to glucose.
Muscle tone- when muscles are slightly
contracted and ready to pull.
Diaphragm- done-shaped muscle that
separates the abdominal and thoracic cavities,
aids in breathing.
1.
Responsible for all body movement.
2.
Responsible for form and shape. (Posture)
3.
Responsible for body heat and maintaining
body temperature.
Atrophy- wasting away of muscles.
Hypertension- an increase in the size of the muscle cell.
Strain- tear in the muscle resulting from excessive use.
Bleeding inside the muscle can result in pain and
swelling. Ice packs will help stop the bleeding and
reduce swelling.
Muscle spasm (cramp)- sustained contraction of the
muscle, usually because of overuse.
Myalgia- muscle pain.
Tendonitis- inflammation of a tendon.
Myasthenia- muscle weakness.
Myocardium- heart muscle or
cardiac muscle.
Myocele- Muscular protrusion
(bulge) through a muscle.
Myocelialgia- pain of the abdomen
muscle.
Myogenic- beginning with muscle.
Myography- record of muscle
contractions.
Myoid-resembling a muscle.
Myoma- tumor containing muscle
tissue.
Myomelanosis- abnormal
darkening of muscle tissue.
Myoparesis- weakness or partial
paralysis of a muscle.
Myoscerosis- hardening of a
muscle.
Myothermic- pertaining to a rise
in muscle temperature.
Tenorrhaphy- suturing of a
tendon.
Tendonitis- inflammation of a
tendon.