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Priscilla Anzaldo P2 Muscular System - Coggle Diagram
Priscilla Anzaldo P2 Muscular System
major functions of the muscular system
produce movement
stabilize joints
maintain body posture and position
generate heat as they conduct
3 types of muscles and their functions
skeletal muscle
produce movement, maintain posture, stabilize joints, generate head when conducting
cardiac muscle
keeping the heart pumping and blood circulation
smooth muscle
contraction
names of skeletal muscles
anterior
facial
frontalis
temporal
orbitularis oculi
zygomaticus minor/ major
masseter
orbicularis oris (mouth)
neck
sternocleiclo mastoid
trapezius
platysma
pectoralis major/ minor
arms
biceps branchi
lateral head
deltoid
brachioradialis
flexor carpi radius
flexi carpi radialis
palmaris
torso
serratus anterior
external oblique
rectus abdominis
legs
iliopsoas
pectineus
adductor longis
gracilis
sartorius
quadriceps formal rectus femoris
vastus laterallis
tensor fascia lata
gastrocnemius (calf)
soleus
exterior digitorum longus
tibialis anterior
posterior
head
occipitalis
neck/ upper back
splenius capitis
trapezius
arms
deltoid
triceps bracchi
extensor carpi radialis longus
brachioradialis
extensor digitorum
extensor carpi ulnarius
flexor carpi ulnaris
back
infraspinatus
teres major
latissimus dorsi
legs
gluteus medius
gluteus maximus
adductor magnus
gracilis
biceps femoris
semimembranosus
semitendinosus
soleus
gastrochrmicus (calf)
fibularis longus
sarcomere
sarcomere:
smallest functional unit of striated muscle tissue. It is the repeating unit between two Z-lines.
located in myofibrils along with
striations, myofilaments, and molecular composition of myofilaments
myofibrils
: densely packed rodlike elements, accounts for 80% of muscle cell volume
striations
: stripes forming from repeating series of dark/light bands along length of each myofibril
A band:
dark region
H zone:
lighter region of middle in A bond
M line:
line of protein (myomesin)
I band:
lighter region
Z disc (line)
: coin- shape sheet of proteins of middle of light I band
myofilaments:
orderly arrangements of actin and myosin myofilaments within sarcomere
actin myofilaments:
thin filaments that extend across I band and partway in A band
molecular composition of myofilaments
thick filaments:
composed of protein myosin that contains 2 heavy and 4 light polypeptide chains
thin filaments:
composed of fibrous protein
actin
actin
: polypeptide made up of kidney- shaped G actin subunits
tropomyosin and troponin:
regulatory proteins bound to actin
neuromuscular junction
axon
: long threadlike extensions of motor neurons
axon branches end on muscular fiber forming
neuromuscular junction
or
motor end plate
events at neuromuscular junction
AP (action potential) arrives at axon terminal
voltage- gated calcium channels open, calcium enters motor neuron
calcium entry causes release of ACh neurotransmitter into synaptic cleft
ACh diffuses across ACh receptors on sarcolemma
ACh binding to receptors, open gates, allowing NA+ to enter resulting in end plate potential
Acetylcholinesterase degrades ACh (neuromuscular junction stops via exocytosis)
sliding filament theory of muscle contraction
during contraction, thin filaments slide past thick filaments causing actin and myosin to overlap more
nervous system simulates muscle fiber, myosin heads bind to actin forming cross bridge, contraction begins
contraction
: the activation of cross bridges to generate force
action potential in a muscle fiber
4 steps of the cross-bridge cycle
Cross Bridge formation:
high energy myosin head attaches to actin thin filament active site
Working "power" stroke:
myosin head pivots and pulls thin filament toward M line
Cross bridge detachment:
ATP attaches to myosin head, causing cross bridge to detach
Cocking of myosin head:
energy from hydrolysis of ATP cocks myosin head int a high energy state which will then be used in power stroke in next cycle
muscle coverings (CT coverings)
epimysium
: dense irregular CT surrounding entire muscle, may blend with facia
perimysium
: fibrous CT surrounding fascicles (groups of muscle fibers)
endomysium
: fine areolar CT surrounding each muscle fiber
disorders associated with muscular system
muscular dystrophy
: genetic disease that damages the muscle fibers
treatment: no known cure, physical therapy, surgery to improve function
symptoms: muscle weakness, lack of coordination, lack of mobility
risk factors: genetic, different types based on mutation (myotic)
fibromyalgia
: pain and tenderness of muscles, joints, and soft tissues
treatment: physical therapy, relaxation techniques, lifestyle changes
symptoms: fatigue, muscle pain, joint pain
risk factors: physical trauma, infection, prominant in women
myasthenia gravis
: autoimmune disease that causes muscle weakness
risk factors: autoimmune, age, prominant in women
symptoms: muscle weakness hemi- paralysis
treatment: no known cure, medications, thymectomy
cerebral palsy
: abnormality to the brain resulting in disconnect between brain and muscle development
risk factors: brain injury, premature birth, bleeding in brain
symptoms: spastic paralysis, muscle tightness, seizures
treatment: no known cure, medications for symptoms, physical therapy
myositis
: inflammation of the skeletal muscles caused by infection
risk factors: autoimmune, muscle trauma, infection
symptoms: muscle weakness, rash, fatigue
treatment: medication, antibiotics, reduce inflammation