Human Anatomy Muscle Tissue And Structure

Front 1

muscles

Back 1

organs which convert chemically stored energy into mechanical energy

Front 2

muscle glycogen is broken down into...

Back 2

glucose

Front 3

muscle contraction functions

Back 3

cell fibers shorten in response to stimulation, through action of myofilaments, contractions cause movement, maintain posture. produce heat, aid in vascular flow

Front 4

muscle characteristics

Back 4

contractile, irritable, extensible, elastic

Front 5

muscle irritability

Back 5

muscles receive and respond to action potentials (nerve impulses)

Front 6

muscle extensibility

Back 6

muscles are able to be stretched, one stretches as another contracts, antagonistic

Front 7

muscle elasticity

Back 7

muscles return to original shape after contraction or extension

Front 8

muscle atrophy

Back 8

muscles degenerate if nerve supply is lost, if blood supply is inadequate, or from disuse

Front 9

muscle hypertrophy

Back 9

muscle increase in size in reponse to increased use (with no change in fiber number)

Front 10

myoblasts

Back 10

muscle building cells that remain in skeletal muscle as satllite cells to repair damaged muscle tissues

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types of muscle tissue

Back 11

cardiac (heart), skeletal, smooth (visceral)

Front 12

skeletal muscle

Back 12

most abundant, most obvious, flesh or meat that attaches to bones, 40% of total body weight, voluntary, contractions are quick and forceful, striated

Front 13

striations

Back 13

appearence of skeletal muscle, visible under microscope, due to arrangement of thick and thin myofilaments within sarcomeres

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belly

Back 14

gaster, meat, mainly skeletal muscle tissues

Front 15

tendons

Back 15

aponeuroses, dense regular connective tissues, attach to origins (proximal bone) and insertion(distal bone), some tendons have sheaths, bursae

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bursae

Back 16

sacs of synovial fluid between tendon-bone, muscles-bone, ligaments-bone, skin-bone

Front 17

tendonitis

Back 17

inflammation of tendons

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bursitis

Back 18

inflammation of bursae

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tenosynovitis

Back 19

inflammation of tendons, tendon sheath and synovial membranes surrounding certain joints such as wrists shoulders elbows and feet

Front 20

muscle

Back 20

group of fascicles/fasciculi wrapped in epimysium

Front 21

fasciculus

Back 21

bundle of muscle cells(fibers) wrapped in periepimysium

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cell

Back 22

fiber, long straight and wrapped in endomysium, red with more capillaries, mitochondria, and myoglobin, white with low myoglobin

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muscle innervation

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sarcolemma is almost touched by axon terminal/motor end plate, skeletal muscle must receive stimulus before contracting, acetycholinedumped into synaptic cleft initiates muscle action potential

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sarcolemma

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plasma membrane with T-tubules (transverse tubules)

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sarcoplasm

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muslce cell cytoplasm, found in small amounts

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multinucleate

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muscle cells possess numerous peripherally located nuclei

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mitochondria

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muscles cells possess many of these organelles whcih produce ATP

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sarcoplasmic reticulum

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smooth tube-like network covering myofibrils, forms a triad with t-tubules and two terminal cisternae of the sarcoplasmic reticulum

Front 29

myofibrils

Back 29

80% of cell volume is occupied by this proteinaceous material, longitudinally oriented, made up of many short myofilaments

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myofilaments

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|| to each other in overlapping arrays, hence striations

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thick myofilaments

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found in light and heavy meromysin

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thin myofilaments

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found in actin, tropomysin, and troponin

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sarcomere

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functonal contractile unit of skeletal muscle contraction, anatomical unit of a myofibril, delineated by Z-discs (transverse proteinaceous structures)

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I band

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less dense, light area of thin myofilaments isotropic)

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A-band

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dense, dark area of thick myofilaments (anisotropic)

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M-line

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line of threadlike protein molecules

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H-zone or H-band

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areas of only thick myofilaments

Front 38

epicardium

Back 38

outer layer of heart wall, a serous membrane of epithelium and connective tissue, aka visceral layer of serous pericardium

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myocardium

Back 39

middle layer of cardiac muscle

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endocardium

Back 40

inner smooth layer of endothelium and smoothe connective tissue and smooth muscle, in heart

Front 41

cardiac contraction

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inherent, involuntary, vigorous, and autorhythmic

Front 42

cardiac muscle features

Back 42

striated under microscope due to myofilaments and myofibrils, contains a fibrous skeleton, lacks satellite cells---damaged tissue cannot regenerate

Front 43

cardiac muscle cell charactersitcs

Back 43

irregularly shaped or branched, one or two centrally located nuclei, sarcolemma, myofibrils, mitochondria, CT, blood vessels, nerves in between cells, networks of cells, no nerve stimulus required for contraction

Front 44

cardiac sarcolemma

Back 44

thin, poorly defined, and connected by intercalated discs with gap junctions desmosomes and myofbrils that are well ancored to sarcolemmal membranes

Front 45

cardiac myofibrils

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less distinct than in skeletal muscle, may be branched

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cardiac mitichondria

Back 46

ATP producers, more numorus and larger than in skeletal muscle

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major networks of myocardial cells

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walls and septum of stria, walls and septum of ventricles

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functional syncytium

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major myocardial cell networks are known as this, cosidered multi nucleated masses, one fiber stimultated, all contract

Front 49

cardiac contraction

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cardiac contraction not goverend by nerve impulses, generated by SA node (sinoatrial) located in upper wall of right atrium, innervation by autnomic nervous system adjusts rate

Front 50

smooth muscle

Back 50

involuntary, innervated by ANS, small thick fibers, fusiform, staggered fiber arrangement, single oval central located nucleus, intermediate filaments attached to dense bodies, nonstriated, much actin less myosin, fibers can divide

Front 51

fusiform

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small fibers, thick in middle and taper at each end

Front 52

kinds of smooth muscle

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visceral or single unit, and mutliunit smooth

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single unit smooth

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wraparound sheets that form walls of hollow viscera, stomach intestines sphincters, uterus urinary bladder, sheets play role in caliber of lumen, one fiber stiulated by a neuron, adjacent fibers respond as impulse reaches them they contract in sequence in a wave

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multiunit smooth

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walls of alrge blood vessels, arrector pili, intrinsic eye, each fiber has its own motor nerve end plate and only that fiber contractswith stimulation

Front 55

stress relaxation

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fibers strech without developing tension, exibit plasticity