muscle plasma membrane
moves bones
multi-nucleated, longitudinal, striated
voluntary
one nuclei, striated, branched, intercalated
pump blood
involuntary
various functions ex: peristalsis
various organs ex: GI tract
one nuclei, spindled-shaped, no striations
involuntary
ability to respond to certain stimuli by producing electrical signals called action potentials
ability to control and shorten in length when stimulated by an action potential
ability to stretch without damage
ability to return to its original shape and resting length after contraction or extension
dense sheet of C.T. that lines the body wall and limbs
fascia
fascia
fascia
fine sheath of C.T. composed of reticular fibers surround each muscle fiber that extends from fascia to protect ans strengthen skeletal muscle
dense irregular C.T. that surrounds groups of muscle fibers called fascicles that extends from fascia to support and strengthen skeletal muscle
overcoat of dense irregular C.T. that surrounds the entire muscles and extends from fascia to protect and strengthen skeletal muscle
a rope-like band of tissue that connects muscle to bone
a broad flat sheet that atttaches sheet-like muscles needing a wide area of attachment
fusion of mesodernmal cells-once fused the muscle fibers cannot undergo cell division
dilated end sacs of the sarcoplasmic reticulum that butt against the T-tubules from both sides
terminal cisternae
a tranverse tubule and two terminal cisternae on either side
protein in sarcoplasm that contains oxygen used by mitochondria for ATP production
filaments inside a myofibril that are arranged in functional units
Sarcomere
Sarcomeres
narrow plated-shaped regions of dense protein material
Z discs
dark, middle part of sacromere that extends entire length of thick filaments, contains thin filament that overlap thick filaments
lighter, less dense area of sarcomere, contains remainder of thin filaments
"I" bands
"I" bands
narrow region in center of "A" bands, contains thick filaments
"H" zone
hold thick filaments together at center of sarcomere
"M" line
main protein component of thin filaments
actin
actin
actin and myosin
main component of thick myofilament and acts like a motor protein
myosin
mysosin
myosin
regulatory protein that blocks myosin binding sites in relaxed muscles
hold myosin in place during relaxed muscles
changes shape when calcium ions attaches which pulls tropomysosin away so myosin can attach to actin
sliding filament theory
thin filament move inward, "H" and "I" narrow and dissappear in max contracted muscle
width of "A" band and length on myofillaments dont change
Z discs come together and makes sarcomere shorten
cross bridge
a muscle's action protential
sliding of the filaments
Excitation-Contraction coupling
communication between 2 neurons or between a neuron and a target cell
a synapse between a somatic motor neuron and muscle fiber
region if the sarcolemma opposite the synaptic end bulbs which contains acetylcholine
Acetycholine
molecules of a neurotransmitter found in synaotiv vesicles that are in synaptic end bulbs
causes exocytosis of a neurotransmitter into the synaptic cleft which diffuse across the synaptic cleft
happens before muscle fatigue, when a person may feel tired and has desire to stop activity
Central fatigue
Central fatigue
Anaerobic Glycolysis
the extra oxygen over and above the resting oxygen consumption that is taken into the body after exercise
replenishes CP stores, converts lactate into pyruvate ATP production in the heart, liver, kindeys, skeletal muscles, reloads O2 onto myoglobins
Consists of a somatic motor neuron and all skeletal muscle fibers in innervates, all fibers contract in unison
on the size of the motor units and number of activated at one time
process in which the number of active motor units increase, weakest recruited first followed by stronger motor units
brief contractionof all muscle fibers in a motor unit in response to a single action potential
situation where stimuli arriving at different times causing larger contraction
Wave Summation
when a skeletal can only partially relax between stimuli at a rate 20 to 30 times per second
when the fibers is stimulated at 80 to 100 times per second, does not relax at all
skeletal muscle at rest exibiting a small amount of tension
Muscle tone
Muscle tone
tension is constant while muscle length changes and movement occurs
muscle shortens and creates movement to reduce the angle to a joint
muscle tension resists the load and muscle length increases
Muscle contracts, does not change length and no movement occurs
Isometric Contraction
Isometric contraction
irregular transverse thickening of the sarcolemma that connect cardiac muscle fibers to one another
intercalated discs
intercalated discs
Smooth muscle
the act of visceral smooth muscle that squeezes substances through the organs by alternating contracting and relaxing
smooth muscle
Smooth muscles
Smooth muscles
Smooth muscle
growth of skeletal tissues after birth is due to increase in the size of cells
increase in number of cells in skeletal and cardiac muscles
produces new smooth muscle fibers
Pericytes
sudden involuntary contraction of a single muscle within a large group of muscles
Spasms
involuntary muscle contractions
cramps
cramps