chapter 9 muscular system I Flashcards
functions of muscular system?
produce movement
maintain posture
stabilize joints
generate heat
why do muscles generate heat?
use cellular aerobic respiration, lose some energy as heat
functional characteristics of muscle system
excitability/irritability
contractility
extensibility
elasticity
contractibility
shortened when stimulated
extensibility
stretch 3x original length
uterus
elasticity
recoils to original length
skeletal control
voluntary/conscious
controlled by nervous system
cardiac control
involuntary control by endocrine and ANS
smooth control
involuntary control by endocrine and ANS
muscle fibers
muscle cells
what surrounds muscle fibers?
connective tissue
endomysium
around a single muscle fiber
perimysium
around a fasicle (bundle) of fibers
epimysium
covers entire skeletal muscle
fascia
on the outside of the epimysium, surround muscle as a whole
flesh eating bacteria
necrotizing fasciitis
how do u get necrotizing fascia?
from major trauma, attacks soft tissue fascia
what are treatments for necrotizing fascia?
antibiotics
amputation
tissue graft
what does each muscle have?
nerve
artery
vein
ways that muscles attach
direct
indirect
indirect attachment
tendon (cord)
aponeurosis
white cuz of collagen
aponeurosis
flat tendonous tissue
why are the tendon and aponeurosis white?
collagen fibers
attachment sites
origin
insertion
origin attachment site
more stable, proximal
insertion attachment site
more movable
distal to origin in limbs
muscle fiber cell structures
sarcolemma sarcoplasm myofibrils sarcomere sarcoplasmic reticulum
sarcolemma
husk
membrane of muscle fiber
muscular dystrophy (duchenne’s)
inherited x-linked recessive
muscle fibers atrophy; shrinks, weakening
death around 20
weakened sarcolemma
sarcoplasm
glycosomes
myoglobin
what do glycosomes store?
glycogen
what is purpose of glycosomes?
to break down to glucose to feed CAR
purpose of myoglobin?
store O2
myofibrils
muscle protein filaments
rod like structures made up of myosin & actin filaments; protein
myofibrils at rest give what?
distinct striations (bands)
I band
A band
I band
light band
A band
dark band
what is sarcomere and what makes it up?
z-disc to z-disc contractile unit of muscle thick filaments - myosin thin filaments - actin bare zone z disc
thick filaments
myosin
thin filaments
actin
purpose of mysoin filaments
ATPase enzymes
large head groups link thick and thin filaments during contraction
bare zone
lakcs actin filaments at rest
sarcoplasmic reticulum (SR)
specialized SER
stores Ca2+ for muscle contraction
what do muscles do when they contract?
pull on structures they are attached to (trochanter, tubercle, tuberosity, etc.)
action
movements accomplished when it contracts (ex. flexion, extension)
interactions
working together to bring about a desired movement
functional groups
prime mover
antagonist
synergist
prime mover
primarily responsible for desired movement
ex. brachialis
antagonist
opposes the prime mover
ex. triceps
synergist
aids the prime mover by either:
adding extra force
preventing or reducing undesirable movements
ex. biceps
naming skeletal muscle
location shape relative size direction of fibers or fascicles (orientation) location of attachment (origin first) number of heads action
ex of location
tibialis anterior
ex of shape
deltoid, trapezius
ex of relative size
ending with maximus, minimus, longus, brevi
ex of orientation
rectus abdominis
ex of location of attachment
sternocleidomastoid
ex of number of head
prefix of bi, tri, or quad
ex of action
extensor, flexor,… extensor digitorum
im injection site
deltoid
vastus lateralis
