chapter 9 part 1 Flashcards
smooth muscle
-involuntary
-pushes fluid through the digestive tract and the urinary tract (from kidney to bladder)
properties of muscle tissue
-excitablility
-contractibility
-extensibility
-elasticity
excitability
response to stimuli
extensibility
contract with resting
skeletal muscle
-voluntary
-causes movement by pulling tendons
-posture
-support
-regulation (pee and vomit)
-BODY TEMP
microscopic muscle anatomy
microfibrils, myofilaments, sacromeres
epimysium
tissue around entire muscle
-it is a connective tissue
perimysium
tissue dividing muscle into fascicles (fiber bundles)
fascicle
fiber bundle
endomyseum
tissue surrounding individual fiber
-has blood vessels that make coiled networks that are used for flexion and extension
tendons
connect muscle and bone
aponeuroses
connect muscle to muscle
motor end plate
neuromuscular junction
-where the nerve and muscle meet
sarcolemma
plasma membrane of muscle fiber (has nucleus!!!)
sarcoplasm
cytosol of muscle cell (where the myofibrils are!!!!!!)
myoblasts
they fuse and become immature fiber that will later become a myosatellite cell
myosatellite
repairs damaged muscle
myofibrils cause?
muscle contractions
myofibrils are located on?
the ends of muscle on sarcolemma
myofibrils are surrounded by?
sarcoplasmic reticulum
sarcoplasmic reticulum
-filled w calcium
-part of excitation/ contraction
what are myofibrils made of?
myofilaments
what are myofilaments made of?
actin (thin) and myosin (thick)
myofilaments
runs parallel to long axis of the cell
myosin and actin
are arranged in sacromeres
sacromere
functioning unit of muscle cell
-their A bands overlapping is what causes striations
actin
-filaments do not touch
-made of g actin molecules
-bind with myosin cross bridges
-binding sites are covered by tropomyosin when RELAXED
-tropomyosin is held in place by troponin
troponin
needs to bind with calcium to move and expose tropomyosin/ active site
organizational order
fascicle -> fiber -> myofibril -> myofilament -> actin and myosin
myosin
-made of elongated tail and globular head
-STATIONARY molecule
-protein forms M line
-core of tinin connects z line
both hold it in place as stationary
-the head binds to the active site of actin and pulls so the head will bend
-need calcium ions and ATP for contraction
contraction
-muscles get shorter
-H and L bands get smaller
-sliding filament theory