V. Anatomy and Innervation of
Skeletal Muscle Tissue
A. Nerve and Blood Supply
1. Nerves, containing motor neurons,
convey impulses for muscle contraction
2. Contractions burn high degrees of
ATP
a. To make more ATP, oxygen is
needed and supplied by blood
b. Each fiber is contacted by a
capillary
B. Connective tissue Components
1. The term fascia is applied to a sheet
or broad band of fibrous connective
tissue underneath the skin or around
muscles and organs
a. Superficial- under skin
b. Deep- around muscles and
organs
2. Three layers extend from deep fascia
to protect and strengthen skeletal muscle
a. epimysium- outer layer
encircling the whole muscle
b. Perimysium- surround bundles
of 10-100 fibers
c. Endomysium- separate each
muscle fiber
3. Tendons and aponeuroses are
extensions that attach muscle to bone or
other tissue
a. Aponeuroses are broad flat
tendons that tie into the covering
on bone
b. Tendon sheaths enclose tendons
and allow them to slide back and
forth more easily
c. Tenosynovitis is an
inflammation of tendon sheaths
and synovial membranes
C. Motor unit
1. A motor neuron and muscle fibers it
stimulates form a motor unit
2. A motor unit may innervate as few as
10 or as many as 2000 muscle fibers,
with an average of about 150 per unit