Transcript MUSCULAR SYSTEM - Havelock High School Health Occupations

MUSCULAR SYSTEM
Structure of the Muscles
Muscles
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Comprise a large part of the human body
– Nearly half our body weight comes from muscle
tissue
 If you weigh 140 lbs, 60 lbs is from muscle attached
to bones
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Over 650 different muscles
Responsibilities of Muscle System
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1.
2.
3.
3 main:
Body movement (voluntary and
involuntary)
Body form and shape, to maintain posture
Body heat, to maintain body temperature
Types of Muscle
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3 types:
– Skeletal
– Smooth
– Cardiac
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Described as:
– Striated
– Spindle shaped
– nonstriated
Skeletal
(figure 7-1 pg 123)
Attached to the _________
 Called striped or striated b/c they have
cross bandings (striations) of alternating
light and dark bands running perpendicular
to the length
 Voluntary muscle b/c contains nerves under
voluntary control
 Multinucleate
 Sarcolemma is the muscle cell membrane
and the cytoplasm is sarcoplasm
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Smooth (visceral)
figure 7-2
Small and spindle shaped
 Single nuclei
 No striations
 Unattached to bones
 Involuntary muscles; controlled by the
autonomic nervous system
 Found in the walls of internal organs
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Cardiac
figure 7-3
Found only in the ____________
 Striated, branched, and involuntary
 Membranes of adjacent cells are fused at
intercalated discs
 Requires continuous supply of oxygen to
function
 Cardiac muscle cells begin to die after 30
seconds of no oxygen
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Sphincter/Dilator Muscles
Special circular muscles in the openings
b/t the esophagus and stomach; stomach
and small intestine; and in the walls of the
anus, urethra, and mouth
 Open and close to control the passage of
substances
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 Look
at table 7-1 pg 125
 Summarizes
the characteristics of the
3 major muscle types
Naming Skeletal Muscles
Named by location, size, direction, number
of origins, location of origin and insertion,
and action;
 However, not all muscles are named in this
manner
 Look at figures 7-6 and 7-7 pg 130 and
look how the muscles are named
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Location………………….
Size………………………..
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Direction of fibers…….
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Number of origins…….
Location of origin and
insertion…………………
Action flexor……………
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Extensor………………………
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Depressor……………………
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Frontalis – forehead
Gluteus maximus – largest
muscle in the buttock
External abdominal oblique –
edge of the lower rib cage
Biceps – two-headed muscle in
humerus
Sternocleidomastoid – origin in
sternum
Flexor capri ulnaris – flexes the
wrist
Extensor carpi ulnaris –
extends the wrist
Depressor anguli oris –
depresses the corner of the
mouth; raises and lowers
body parts
There are 656 muscles in the human body
 327 antagonistic muscle pairs and 2
unpaired muscles
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– Unpaired muscles: orbicularis oris and the
diaphragm
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The muscles can be divided and
subdivided into the following regions
– Head, neck, and trunk and extremities
Head Muscles
Muscles
 Muscles
 Muscles
 Muscles
 Muscles
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of
of
of
of
of
expression
mastication (chewing)
the tongue
the pharynx
the soft palate
Neck Muscles
Muscles moving the head
 Muscles moving the hyoid bone and the
larynx
 Muscles moving the upper ribs
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Trunk and Extremity Muscles
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Muscles
Muscles
Muscles
Muscles
Muscles
Muscles
digits
Muscles
Muscles
Muscles
Muscles
that move the
that move the
of breathing
that move the
that move the
that move the
that
that
that
that
vertebral column
scapula
humerus
forearm
wrist, hand, and finger
act on the pelvis
move the femur
move the leg
move the ankles, feet, and toe digits
Muscles of the Head and Neck
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Control human facial expressions such as:
– What are some examples? (think of feelings)
– Refer to table 7-2 and figure 7-8
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Muscles of mastication control the mandible,
raising it to close the jaw and lowering it to open
the jaw.
– Refer to table 7-3 and figure 7-8
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Muscles that move the head cause extension,
flexion, and rotation
– Refer to table 7-4 and figure 7-8
Muscles of the Upper Extremities
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Help to move the scapula and humerus
and forearm, wrist, hand, and fingers
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Refer to table 7-5 and figure 7-9
Muscles of the Trunk
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Control breathing and the movements of
the abdomen and the pelvis
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Refer to table 7-6 and figure 7-10
Muscles of the Lower Extremities
Assist in the movement of the femur, leg,
ankle, foot, and toes
 Hamstrings comprised of: semitendinosus,
biceps femoris, and semimembranosus
muscles
 Tendons of these muscles attach
posteriorly to the tibia and fibula (can be
felt behind the knee)
 Responsible for flexing the knee
 Refer to table 7-7 and figure 7-11
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