T HE N ERVOUS S YSTEM Chapter 33. S TRUCTURE OF N ERVOUS S YSTEM Section 1.
M USCULAR S YSTEM Medical Science I. M USCULAR S YSTEM Over 650 muscles Nearly half our body weight...
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Transcript of M USCULAR S YSTEM Medical Science I. M USCULAR S YSTEM Over 650 muscles Nearly half our body weight...
MUSCULAR SYSTEM
Medical Science I
MUSCULAR SYSTEM Over 650 muscles Nearly half our body weight comes
from muscles Consist of muscles and connective
tissueMuscles give us form and shape.Muscles produce most of our body
heat.
TYPES OF MUSCLES Skeletal muscle Smooth muscle Cardiac muscle Sphincter muscle
SKELETAL MUSCLES muscles attached to bones striped or striated because of bandings Voluntary muscles Multinucleated muscle cell bundles = muscle
fibers SARCOLEMMA = cell membrane Contract quickly, fatigue easily, can’t maintain
contraction for long period of time
SMOOTH MUSCLE Found in walls of digestive system,
uterus and blood vessels Visceral muscle Only one nucleus No striations Involuntary controlled by autonomic
nervous system
CARDIAC MUSCLE Involuntary heart muscle Striated and branched Involuntary Cells are fused – when one contracts,
they all contract
SPHINCTER MUSCLE Special circular muscles Open and close to control passage of
substances in openings of esophagus, stomach,
small intestine, anus, urethra and mouth
TYPES OF CONNECTIVE TISSUE Tendons Fascia
TENDONS Connect skeletal muscle to bone
FASCIA Fibrous connective tissue sheets that wrap
around muscle bundles
MUSCLE CHARACTERISTICS
ContractibilityElasticityExcitabilityExtensibilityTone
CONTRACTILITY when a muscle shortens and reduces
the distance between two parts
ELASTICITY- ability to return to the original length
when relaxed
EXCITABILITY ability to respond to stimuli
EXTENSIBILITY ability to be stretched
MUSCLE TONE Is a stat e of being slightly contracted
and ready to pull Isotonic- muscle contracts and
shortens ex. Walk Isometric- tension increase but doesn’t
shorten ex. Crunches Atrophy- muscle may shrink or waste
away from lack of use Hypertrophy- enlargement of the
muscle cell
MUSCLE FATIGUE Is caused by a build up of lactic acid in
muscles which impedes contraction Oxygen converts lactic acid back to
glucose after exercise oxygen debt- amount of oxygen
needed after exercise to return lactic acid back to glucose
HOW MUSCLES ARE NAMED Location of muscle Size Number of origins Location of origin Action Not all muscles are named this way
MUSCLES OF FACIAL EXPRESSION Frontalis- raises eyebrows & wrinkles
forehead Orbicularis oris- open and close lips Orbicularis oculi- closes eyelid Zygomatic major- raises corners of mouth
(smiling) Buccinator- cheek muscles
MUSCLES OF MASTICATION
Massester- closes jaw
Temporalis- Raises jaw, closes mouth and moves jaw backward
Sternocleidomastoid- flexes head, rotates head
MUSCLES OF THE NECK
HEAD AND NECK MUSCLES
TORSO/TRUNK MUSCLES (ANTERIOR)
MUSCLES OF THE TRUNK/TORSO External intercostals- raise ribs helps
w/ breathing Diaphragm- helps control breathing Rectus abdominis-compresses
abdomen External and internal obliques-
decompress ribs, flexes spinal column and abdominal cavity
Latissimuss dorsi- extension, adduction, flexion from standing and internal rotation of the shoulder
TORSO/TRUNK MUSCLES (POSTERIOR)
MUSCLES OF UPPER EXTREMITY Trapezius-moves shoulders, extends head Deltoid-abduct the upper arm Pectoralis major- flex upper arm, helps
abduct upper arm Biceps brachii- flexes lower arm Triceps brachii-extends lower arm Brachioradialis- pronation/supanation,
flex at elbow
UPPER EXTREMITY MUSCLES
MUSCLES OF THE LOWER EXTREMITY Gluteus Medius-abducts and rotates
thigh Gluteus Maximus-extends femur and
rotates outward Vastus lateralis- extends knee Vastus medalis- stabilizes patella Gastrocnemius-points toe and flexes
lower leg
MUSCLES OF THE LOWER EXTREMITY Soleus- extends foot Sartorius- flexes and rotates thigh and
leg Tibialis anterior- dorsiflex foot, walking
on heel Rectus femoris- flexes thigh & extends
lower leg
MUSCLES OF THE LOWER EXTREMITY Hamstrings- a group of four muscles
on the BACK of the thigh Quadriceps- group of four muscles on
the FRONT of the thigh
LOWER EXTREMITY MUSCLES
FUNCTIONS OF THE MUSCULAR SYSTEM Movement Posture Body heat
MOVEMENT Skeletal muscle-origins and insertions
help muscles move origins- part of skeletal muscle attached to fixed
structure Insertions- attached to moveable part
MOVEMENT Smooth muscle- causes movement of
the digestive system Cardiac muscle causes movement of the
heart Acetycholine- chemical neurotransmitter Motor unit-motor neuron plus all the
muscle fibers it stimulates Neuromuscular junction- junction
between the motor neuron fibers which transmits the impulse, and the muscle cell's sarcolemma
POSTURE How does the muscular system help
with posture?
BODY HEAT Muscles release ATP for energy When ATP is released it produces heat
and energy
DISORDERS OF THE MUSCULAR SYSTEM Fibromyalgia Hernia Muscle spasms Muscular dystrophy Myasthenia gravis Strain Tendonitis Tetanus
FIBROMYALGIA A collection of symptoms
Chronic muscle pain 3 or more month Fatigue Headache Numbness and tingling Joint pain
Treatment is pain relief, enough sleep, exercise, massage, chiropractor, and stretching
HERNIA When an organ protrudes through a
weakened muscle 3 types
Abdominal Inguinnal Hiatal
http://www.youtube.com/watch?v=R6pwlIVQPVA
MUSCLE SPASMS Also called muscle cramp Sustained contraction of the muscle,
which may be due to overuse
MUSCULAR DYSTROPHY Muscle cells deteriorate Most common type is Duchenne’s
which is a birth defect Symptoms
Muscle weakness that progresses Falls Delayed walking
No treatment managing symptoms only
MYASTHENIA GRAVIS Autoimmune disorder- immune system
attacks healthy tissue Symptoms-
Voluntary muscle weakness Difficulty swallowing or chewing Paralysis
Treatment Plenty of rest Avoid stress and heat Medications There is no cure
http://www.youtube.com/watch?v=mt0efT2xk2Y
STRAIN A tear in the muscle resulting from
excessive use Treatment=RICE
Rest Ice Compression Elevation
TENDONITIS Inflammation of the tendons Symptoms
Joint stiffness Heat Redness Swelling
Treatment RICE medication
TETANUS Also called lockjaw Caused by toxin entering through puncture
wound Symptoms
Spasms of voluntary muscles that start in jaw and move throughout body
Treatment Antibiotics Rest
Tetanus vaccine to prevent http://
www.youtube.com/watch?v=AX5K_uvhL6w http://
www.youtube.com/watch?v=lCZxffNcFxw