apII ch9 quiz 6/3
Terms
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- muscle types:
-
skeletal
cardiac
smooth - muscles are classified by:
-
structure
funcion
location - what are the other names for muscle cells?
- myocytes or fibers
- what does muscle contraction depend on?
-
two kinds of myofilaments:
actin
myosin - what are actin and myosin
- protiens
- skeletal muscle chracteristics:
- multi-nucleated, long thin sylinder shaped, striated, voluntary, attached to muscles, rapid contractions
- cardiac muscle chracteristics:
- interclated disks(reinforce fibers), in heart, striated, involuntary, bifrucated, rythmic contractions, uninucleated
- smooth muscle characteristics:
- non-striated, in walls of hollow visceral organs and blood vessles and skin, involuntary, slow and sustained contractions, uninucleated, spindle shaped
- funtions of the muscular system:
- movement, posture maintenance and body support, joint stability, heat generation, support soft tissue, guard entrances and exits
- functional characteristics of muscle:
- excitability, contractility, extensibility, elasticity
- facia-
- separates individual skeletal muscles from adjacent muscles and holds them in position by layers of dense CT
- tendon-
- a cordlike sturcture that is formed from dense CT projecting beyond the end of its muscle connecting it to bone; an extention of the fibers (linked sausages)
- tendinitis
- (tendonitis) tendon becomes inflamed and swollen after an injury of repeated use
- tenosynovitis
- connective sheath of a tendon may become inflammed and swollen
- aponeurosis
- a sheet like structure formed from dense CT associated with muscle may attach to bone or the coverings of adjacent muscle
- fascicle-
- a section (portion) of a muscle consisting of a bundle of muscle fibers and surrounded by a perimysium
- epimysium-
- a layer of CT that closely surrounds a SKELETAL muscle (covers whole)
- perimysium-
- CT that extends inward from the epimysium and separates muscles into FASCICLES and possesses collagen and elastic fibers, blood vessels, and nerves
- endomysium-
- the thin layer of CT that surrounds each of the individual muscle cells and interconnects adajacent muscle fibers.
- the endomysium contains:
- capillary networks, satellite cells, nerve fibers
- deep fascia-
- portion of the fascia that surrounds or penetrates muscles
- subcutaneous fascia-
- continuous from deep fascia; is fascia just beneath the skin forming the subcutan. layer
- subserous fascia-
- CT layer of the serous membranes covering organs in various body cavities and lining those cavities
- another term for single muscle cell?
- fiber
- sarcolemma-
- the plasma cell membrane of a muscle cell, surrounds cytoplasm
- sarcoplasm-
- the cytoplasm of a muscle cell
- look at sarcoplasmic reticulum
- look at transvers tubules
- triad-
- formed by a transvers tubule surrounded by tow cisternae of t tubules near the region where actin and myosin filaments overlap
- myofibrils-
- threadlike structures located in the sarcoplasm and anchored to the inner surface of the sarcolemma, play a fundamental role in the muscle contraction mechanism
- each cylindrical _ consists primarily of two types of protein _ called?
-
myofibril, myofilaments;
thick myosin and thin actin - actin contains two proteins called:
- troponin and tropomyosin
- sarcomere-
- a segement of a myofibril or a contractile unit located from z-line to z-line, a structural and functional unit
- a of myofilaments:
- each myosin molecule consists of 2 twisted protein strands w globular parts called CROSS BRIDGES (HEADS); project outward toward actin
- a of actin:
- thin filaments consists of double strands of actin twisted into a helix (2 pearl strands); actin has a binding site to which the cross-bridges or a myosin can attach
- what are the 2 proteins associated w actin filaments:
- tropomyosin troponin
- troponin molecules have 3 protein subunits:
- one binds to actin, one binds to tropomyosin, one binds to calcium ions
- neuromuscular junction-
- (myoneural juntion) the site where the axon and muscle fiber meet
- motor end plate-
- a specialized portion of the muscle cell membrane that is extensively folded with abundant nuclei and mitochondria (usually 1 per muscle fiber); part of sarcolemma
- motor unit-
- a motor neuron and the muscle fibers it controls
- motor neuron-
- carries impulse from cns to effector
- synaptic cleft-
- separates the membranes of the neuron and the membrane of the muscle fiber
- synaptic visicles-
- in the cytoplasm at the distal ends of nerve fibers store chemicals called NEUROTRANSMITTERS
- sliding filament theory-
- hugh huxley; when sarcomeres shorten, the thick and thin filaments slide past one another. the actin filaments move toward the center of the sarcomere from both ends
- acetylcholinesterase-
- decomposes acetylcholine remaining in the synapse; in the synapse and on the membranes of the motor end plate
- creatine phosphate-
- an energy source available to generate ATP from ADP
- glycolysis-
- what muscle cells depend on to synthesize ATP after creatine phosphate is used
- myoglobin-
- carries oxygen inside fiber; temporarily stores oxygen when contracted, a pigment that produces RED color in muscle tissue, , reduces the muscles need for a continuous blood supply during contraction, this is importan becasue....
- contraction does what?
- decreases blood flow
- lactin acid threshold-
- a rapid increase in blood vessels, is made when oxygen supply is to low to sustain aerobic reactions
- oxygen debt-
- amount of oxygen needed for reactions to occur to get back to original concentrations
- fatigue-
- the condition in which a muscle fiber cannot contract
- cramp-
- a painful condition in which a muscle undergoes a sustained, involuntary contraction
- heat-
- by product of cellular respiration, all cells generate heat
- threshold stimulus-
- the minimal stimulus needed to start a muscle contraction
- twitch-
- the response of a single muscle fiber to the ACh released by a single action potential and invloves a period of contraction followed by a period of relaxation
- myogram-
- a recording of the events of a muscle twitch
- three periods of a muscle fiber
- latent-between stimulation and beginning of the contraction; contraction- a muscle fiber is generating force or contracting; relaxation- the period in which a muscle fiber is decreasing tension
- refractory period-
- the period in which a muscle fiber is unresponsive to stimulation
- muscle fibers have an - - - response.
- all or none
- summation-
- the combination of the force of individual twitches
- tetanic contractions-
- (tetanus) contractions that lace relaxation
- recruitment-
- an increase in the number of activated motor units.
- muscle tone-
- (tonus) the amount of sustained contractions in a muscle; this is important for maintaining posture
- types of contractions:
- isotonic; concentric; eccentric, isometric
- isotonic contraction-
- a tyupe of contraction that produces movement of a body part
- concentric contraction-
- an ISOTONIC contraction in which shortening of the muscle occurs
- eccentric contraction-
- an ISOTONIC contraction in which lengthening of the muscle occurs
- isometric contraction-
- a contraction in which muscle tension increases but no movements ob body parts are produced
- rhythmicity-
- a pattern of spontaneous repeated contraction
- peristalisis-
- a wavelike motion produced by smooth muscle contration
- syncytium-
- a group of muscle fibers that contract as a unit
- origin-
- the immovable end of the muscle
- insertion-
- the moveable end of the muscle
- prime mover-
- (agonist) the muscle primarily responsible for producing an action
- synergist-
- a muscle that assistss the prime mover
- antagonist-
- a muscle that resists the action of a prime mover
- flextion-
- decreasing of angle
- extention-
- increasing of angle
- strain-
- muscle fibers and ass. CT are torn due to overstrectching
- convulsion-
- series of involuntary contractions of various voluntary muscles
- fibrosis-
- degenerative disease in which CT w many fibers replaces skeletal muscle tissue
- fibrositis-
- inflammation of CT w many fibers; especially in the muscle fascia; also called muscular rheumatism
- muscular dytrophy-
- progressive muscular weakness and atrophy caused by deficient dystrophin protein
- myalgia-
- pain resulting from any muscualr disease or disorder
- myology-
- study of muscles
- myoma-
- tumor composed of muscle tissue
- myopathy-
- any muscular disease
- paralysis-
- loss of ability to move a body part
- atrophy-
- the decrease in size and strength of a muscle
- hypertrophy-
- the enlargement of muscle that a forcefully exercised
- sphincter-
- a ringlike band of muscle
- myasthenia gravis-
- chronic disease that makes muscles weak and fatigued. results from immune system;s attack on neuromuscular junctions
- shin splints-
- soreness on the front of the leg due to straining of anterior lege muscles often resulting from walking up and down hills