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MUSCLES
HCS 1050 SLO 2
TYPES OF MUSCLES
• Smooth muscles
Location: Makes up the walls of hollow body
organs, blood vessels, respiratory,
passageways
Cell Characteristics: Tapered at each end,
branching networks, non-striated
Control Action: Involuntary
Produces peristalsis; contracts and relaxes
slowly, may sustain contraction
SMOOTH MUSCLE
TYPES OF MUSCLE
• Cardiac Muscle
Location: Wall of the heart
Cell Characteristics: Branching networks;
special membranes between cells; single
nucleus; lightly striated
Control Action: Involuntary
Pumps blood out of heart; self-excitatory my
nervous system and hormones
CARDIAC MUSCLE
TYPES OF MUSCLE
• Skeletal Muscle
Location: Attached to bones
Cell Characteristics: Long and cylindrical;
multinucleated; heavily striated
Control Action: Voluntary
Produces movement at joints; stimulated by
nervous system; contracts and relaxes rapidly
SKELETAL MUSCLE
THREE PRIMARY FUNCTIONS OF
SKELETAL MUSCLES
1) Movement of the skeleton
- muscles are attached to bones and
contract to change position of the bones at a
joint
2) Maintenance of posture
- a steady partial contraction of muscle,
known as muscle tone, keeps the body in
position
3) Generation of heat
- muscles generate most of the heat needed to
keep the body at 37 degrees Celsius
THE MECHANICS OF MUSCLE
MOVEMENT
• Most muscles have two or more points of
attachment to the skeleton.
• Muscles are attached to a bone at each end
by a cordlike extension called a tendon.
• One end of the bone is attached to a relatively
stable, less movable attachment called the
origin
• The other end of the muscle attaches to a body
part that the muscle puts into action. This is
called the insertion
TENDONS, ORIGINS AND INSERTIONS
• Fascia or Deep Fascia covers, separates
and protects skeletal muscle
• Ligaments are bands of connective tissue
that connect a bone to another bone
• Cartilage is found on the bone surfaces of
freely movable joints and form a smooth
layer also known as articular cartilage.
Some complex joints such as the knee, also
have additional cartilage between the
bones (crescent-shaped medial and lateral
meniscus)
LIGAMENTS OF THE KNEE
FASCIA
CARTILAGE
HOW MUSCLES ARE NAMED
• Location – using a nearby bone, a position
such as lateral, medial, internal or external
• Size – using terms such as maximus, major,
minor, longus, or brevis
• Shape – such as circular (orbicularis),
triangular (deltoid) or trapezoid (trapezius)
• Direction of fibers – including straight (rectus)
or angled (oblique)
HOW MUSCLES ARE NAMED
• Number of heads (attachment points)example biceps, triceps and quadriceps
• Action – as in flexor, extensor, adductor,
abductor or levator