Muscle Physiology Flashcards
Can contract, movement possible, can move entire body and within body.
muscle tissue
Supports the body, moves bones, maintains body temperature, movement of cardiovascular and lymphatic vessels, Protection of bones, organs, joints. Communication.
function of skeletal muscle
______ are Long, cylindrical, Multinucleated, can be very long, striated.
muscle fibers
Number of muscle fibers remains ____ after birth
constant
Enlargement of muscles due to increase in ____ not number
size (hypertrophy)
surrounds entire muscle, becomes part of fascia (separates muscles from each other), extends to form tendons
epimysium
surface area =
volume ratio
surrounds bundles of muscle fibers
perimysium
thin layer of aerolar connective tissue, surrounds each skeletal muscle fiber
endomysium
bundles of myofilaments
myofibril
contractile unit
sarcomere
cell membrane of muscle cell
sarcolemma
cytoplasm of muscle cell. Glycogen,
myoglobin and organelles found here
sarcoplasm
cylindrical in shape and run the length of the
muscle fiber. increase in size when you lift weights
myofibril
endoplasmic reticulum of muscle
cell. Contains calcium & critical for muscle contraction
Sarcoplasmic Reticulum
extension of sarcolemma that extends into the
muscle fiber, conveys impulses that cause SR to release CA2+
T-tubules
the contractile unit of a muscle cell.
There are many per myofibril. Defined by “Z-line”
boundaries.
sarcomere
red pigment that stores oxygen for muscle contraction (like hemoglobin)
myoglobin
composed of several hundred
molecules of myosin (shaped like golf clubs)
thick filament
composed of actin.
has two proteins associated with it: troponin and
tropomyosin. Released into blood during heart attack
thin filament
The theory that describes how actin and myosin slide past each other in a muscle contraction
sliding filament theory
both myosin and actin _____ during a muscle contraction
stay the same size
True/False: ATP is Required for Muscle Contraction
True
A bands (myosin) _____ during shortening of a muscle
remain a constant width
I bands and H zones become
more narrow (gaps between actin molecules close)
Z lines (boundaries of sarcomere) move
closer together
all along the myofibril are many ____
sarcomeres
muscle cell has many ___
myofibrils
myofibril has many ____
myofilaments, actin + myosin, proteins
Neurotransmitter responsible for muscular contractions
ACH (Acetylchloline)
ACh binds to receptors on ______ on sarcolemma, generating an impulse in sarcolemma
motor end plate
Energy for muscle contractions is supplied by ____
ATP
Energy is released when ___
ATP > ADP + Pi
ATP helps form ____ between myosin and actin
cross-bridge formation
New ATP must bind to ____ before cross-bridge is released
myosin
When a person or animal dies, No ATP is available to release cross-bridges, stiffness
rigor mortis
Muscles always have a point of ___ where they crom from, this is stationairy bone; close to midline
origin
Have a point of ____ this bone moves and is away from the midline
insertion
the one muscle in group that does most of the work
prime mover
other muscles that help are called
syngerists
do opposite tasks
antagonists
long, cylindrical, can be very long, striated, multinucleated
skeletal muscle
narrow, tapered, cylindrical. nonstriated, walls of organs and blood vessels
smooth muscle
sriated, cylindrical, branched, uninucleated fibers.
cardiac muscle
What mediates impulses in sarcolemma?
sodium NA+
Calcium is released from ________
Sarcoplasmic Recticulum
