Download Skeletal Cell Structure

Skeletal Cell
Structure
Human body contains over 400 skeletal
muscles 40-50% of total body weight
Functions of skeletal muscle
Body movement (Locomotion)
Maintenance of posture
Respiration
Diaphragm and intercostal contractions
Communication (Verbal and Facial)
Constriction of organs and vessels
Production of body heat (Thermogenesis)
Epimysium
Surrounds entire muscle
Perimysium
Surrounds bundles of muscle fibers
Endomysium
Surrounds individual muscle fibers
• Epimysium is fibrous elastic
tissue that surrounds each
muscle.
Fasciculus is a small bundle of
muscle, tendon, or nerve fibers
wrapped by a layer of
connective tissue called the
perimysium (muscle) or
perineurium (nerve fiber).
• Perimysium is the name given to
the fibrous sheath that
surrounds (covers) each bundle
of single muscle fibers, the
bundle being known as a
fascicle.
Endomysium is the delicate
connective tissue surrounding
the individual muscular fibers
within the smallest bundles
• Sarcolemma is the name of
the cell membrane that
encloses each muscle cell.
Each muscle fiber itself
contains cylindrical
organelles known as
Myofibrils.
The Epimysium protects the
muscle from friction against
other muscles and bones.
It also continues at the end of
the muscle to form (along with
other connective tissues) the
muscles tendon.
Looking at the cross section of
the muscle you can see bundles
of fibres / fibers, known as
Fasciculi, which are surrounded
by another connective tissue,
called the Perimysium.
Endomysium insulates each
muscle fiber.
Beneath the Endomysium and
surrounding the muscle fibre is
the Sarcolemma
and beneath this is the
Sarcoplasm, which is the cells
cytoplasm
Sarcoplasm contains Glycogen and
Fats for energy and also Mitochondria
Each muscle fiber contains hundreds
to thousands of Myofibrils. These are
bundles of Actin and Myosin proteins
which run the length of the muscle
fiber and are important in muscle
contraction.
Surrounding the Myofibril there is a
network of tubules and channels
called the Sarcoplasmic Reticulum
in which Calcium is stored which is
important in muscle contraction.