Anatomy_Key Terms_Ch10 Flashcards
myofilaments
specific types of microfilaments that are responsible for the shortening of muscle cells; there are two kinds, one containing the protein actin and the other containing the protein myosin
contractility
muscle tissue contracts forcefully, muscle cells contain myofilaments
excitability
“nerve signals or other stimula excite muscle cells, causing electrical impulses to travel along the cells’ plasma membrane and initiate contraction in muscle cells”
extensibility
muscle tissue can be stretched
elasticity
after being stretched, muscle tissue recoils passively and resumes its resting length
sarcolemma
plasma membrane of muscle cells
sarcoplasm
cytoplasm of muscle cells
skeletal muscles
discrete organs that attach to and move the skeleton
striated muscle
has dark and light stripes extending transversely across its muscle cells, visible when the tissue is viewed histologically
epimysium
an outer layer of dense, irregular connective tissue surrounds the whole skeletal muscle
perimysium
a layer of fibrous connective tissue surrounding each fascicle
fascicle
a group of muscle fibers
endomysium
within a fascile, each muscle fiber is surrounded by a fine sheath of loose connective tissue consisting mostly of reticular fibers
tendon
all three sheaths converge to form the _, the connective tissue structure that joins skeletal muscles to bones
origin
attachment of the muscle on the less movable bone (but can sometimes switch), in the limbs by convention is the more proximal attachment of the muscle
insertion
attachment of the muscle on the more movable bone (but can sometimes switch), by convention in the limbs is the more distal attachment
aponeurosis
flat sheet formed by the connective tissue extending well beyond the end of the muscle fibers (indirect attachments)
myofibrils
unbranched cylinders that are present in large numberso making up more than 80% of the sacroplasm, specialized contractile organelles unique to muscle tissue, contain myofilaments
sarcomeres
”"”muscle segments””, basic unit of contraction in skeletal muscle”
Z discs/Z lines
boundaries at the two ends of each sarcomere
thin (actin) filaments
many fine myofilaments attached to each Z disc and extending toward the center of the sarcomere
tropomyosin
regulatory protein found on the thin filament, forms a thin strand that spirals around the actin molecule
troponin
regulatory protein found on the thin filament, attaches the tropomyosin strand to the actin molecule
thick (myosin) filaments
consist largely of myosin molecules, contain ATPase,cylindracial bundle in the center of the sarcomere and overlapping the inner ends of the thin filaments
A band
region of each sarcomere of dark bands created by the full length of the thick filaments in the sarcomeres along with the inner ends of the thin filaments which overlap the thick filaments, anisotropic
H zone
the centarl part of an A band, where no thin filaments reach
M line
center of the H zone, contains tiny rods that hold the thick filaments together
I bands
two regions on either side of the A band, regions that contain only thin filaments, light portions, isotrapic
titin
springlike molecule in sarcomeres that resists overstretching
sarcoplasmic reticulum (SR)
elaborate smooth endoplasmic reticulum whose interconnecting tubules surround each myofibril
terminal cisterns
form larger, perpendicular cross channels over the junction between each A band in a myobibril and its adjacent I bands (A-I junctions), stores large quantities of calcium ions
T tubules
transverse tubules, deep invaginations of the sarcolemma that run between each pair of terminal cisterns
triad
complex of the T tubule flanked by two terminal cisterns at the A-I junction
motor neurons
nerve cells that innervate muscle fibers
neuromuscular junction
aka motor end plate, the point at which the nerve ending and fiber meet
terminal boutons
aka axon terminals, clusters of enlargements a the end of the axonal process that stores chemical messenger molecules, neurotransmitters
synaptic cleft
space separating terminal boutons from the sarcolemma of the muscle fiber
motor unit
a motor neuron and all the muscle fibers it innervates
recruitment
the addition of motor units to accomplish a movement
oxidative fibers
muscle fibers that predominantly produce ATP aerobically
glycolytic fibers
muscle fibers that make ATP anaerobically via glycolysis
muscular dystrophy
a group of inherited muscle-destroying diseases that generally appear in childhood, the affected muscles enlarge with fat and connective tissue while the muscle fibers degenerate
Ducheene muscular dystrophy
most common and most serious form of muscular dystrophy
myotonic dystrophy
inherited and slow-progressing, symptoms include skeletal-muscle spasms followed by muscle weakness and abnormal heart rhythm
myofascial pain syndrom
pain is caused by tightened bands of muscle fibers that twitch when the skin over them is touched, the sensitive areas of skin are called trigger points
fibromyalgia
mysterious chronic-pain syndrome of unknown cause, symptoms include severe musculoskeletal pain, fatigue, sleep abnormalities, and headache
sarcopenia
loss of muscle leads to a decrease in muscular strength, usually by 50% by age 80
specific types of microfilaments that are responsible for the shortening of muscle cells; there are two kinds, one containing the protein actin and the other containing the protein myosin
myofilaments
muscle tissue contracts forcefully, muscle cells contain myofilaments
contractility
“nerve signals or other stimula excite muscle cells, causing electrical impulses to travel along the cells’ plasma membrane and initiate contraction in muscle cells”
excitability
muscle tissue can be stretched
extensibility
after being stretched, muscle tissue recoils passively and resumes its resting length
elasticity
plasma membrane of muscle cells
sarcolemma
cytoplasm of muscle cells
sarcoplasm
discrete organs that attach to and move the skeleton
skeletal muscles
has dark and light stripes extending transversely across its muscle cells, visible when the tissue is viewed histologically
striated muscle
an outer layer of dense, irregular connective tissue surrounds the whole skeletal muscle
epimysium
a layer of fibrous connective tissue surrounding each fascicle
perimysium
a group of muscle fibers
fascicle
within a fascile, each muscle fiber is surrounded by a fine sheath of loose connective tissue consisting mostly of reticular fibers
endomysium
all three sheaths converge to form the _, the connective tissue structure that joins skeletal muscles to bones
tendon
attachment of the muscle on the less movable bone (but can sometimes switch), in the limbs by convention is the more proximal attachment of the muscle
origin
attachment of the muscle on the more movable bone (but can sometimes switch), by convention in the limbs is the more distal attachment
insertion
flat sheet formed by the connective tissue extending well beyond the end of the muscle fibers (indirect attachments)
aponeurosis
unbranched cylinders that are present in large numberso making up more than 80% of the sacroplasm, specialized contractile organelles unique to muscle tissue, contain myofilaments
myofibrils
”"”muscle segments””, basic unit of contraction in skeletal muscle”
sarcomeres
boundaries at the two ends of each sarcomere
Z discs/Z lines
many fine myofilaments attached to each Z disc and extending toward the center of the sarcomere
thin (actin) filaments
regulatory protein found on the thin filament, forms a thin strand that spirals around the actin molecule
tropomyosin
regulatory protein found on the thin filament, attaches the tropomyosin strand to the actin molecule
troponin
consist largely of myosin molecules, contain ATPase,cylindracial bundle in the center of the sarcomere and overlapping the inner ends of the thin filaments
thick (myosin) filaments
region of each sarcomere of dark bands created by the full length of the thick filaments in the sarcomeres along with the inner ends of the thin filaments which overlap the thick filaments, anisotropic
A band
the centarl part of an A band, where no thin filaments reach
H zone
center of the H zone, contains tiny rods that hold the thick filaments together
M line
two regions on either side of the A band, regions that contain only thin filaments, light portions, isotrapic
I bands
springlike molecule in sarcomeres that resists overstretching
titin
elaborate smooth endoplasmic reticulum whose interconnecting tubules surround each myofibril
sarcoplasmic reticulum (SR)
form larger, perpendicular cross channels over the junction between each A band in a myobibril and its adjacent I bands (A-I junctions), stores large quantities of calcium ions
terminal cisterns
transverse tubules, deep invaginations of the sarcolemma that run between each pair of terminal cisterns
T tubules
complex of the T tubule flanked by two terminal cisterns at the A-I junction
triad
nerve cells that innervate muscle fibers
motor neurons
aka motor end plate, the point at which the nerve ending and fiber meet
neuromuscular junction
aka axon terminals, clusters of enlargements a the end of the axonal process that stores chemical messenger molecules, neurotransmitters
terminal boutons
space separating terminal boutons from the sarcolemma of the muscle fiber
synaptic cleft
a motor neuron and all the muscle fibers it innervates
motor unit
the addition of motor units to accomplish a movement
recruitment
muscle fibers that predominantly produce ATP aerobically
oxidative fibers
muscle fibers that make ATP anaerobically via glycolysis
glycolytic fibers
a group of inherited muscle-destroying diseases that generally appear in childhood, the affected muscles enlarge with fat and connective tissue while the muscle fibers degenerate
muscular dystrophy
most common and most serious form of muscular dystrophy
Ducheene muscular dystrophy
inherited and slow-progressing, symptoms include skeletal-muscle spasms followed by muscle weakness and abnormal heart rhythm
myotonic dystrophy
pain is caused by tightened bands of muscle fibers that twitch when the skin over them is touched, the sensitive areas of skin are called trigger points
myofascial pain syndrom
mysterious chronic-pain syndrome of unknown cause, symptoms include severe musculoskeletal pain, fatigue, sleep abnormalities, and headache
fibromyalgia
loss of muscle leads to a decrease in muscular strength, usually by 50% by age 80
sarcopenia
