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49 terms

muscle tissue

STUDY
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excitability
ability of a muscle to be stimulate by a motor neuron
contractility
ability of a muscle to shorten when stimulated
extensibility
ability of a muscle to relax when contraction is done
elasticity
ability of a muscle to continually contract and relax over and over and not change shape
skeletal muscle tissue
attached by tendons to bones, multinucleate,parallel fibers,striated,movement of skeleton and posture,voluntary,contracts quickly
smooth muscle tissue
walls of hollow organs, ex:bladder,vessels,digestive,spindle shaped, single nucleus, not striated, movement of materials in organs:peristalsis,involuntary, rhythmic,self exciting,very slow
cardiac muscle tissue
only in the heart,striations, single nucleus,intercalated disc,branching fibers,pumps blood,involuntary,self-exciting,rhythmic,slow
voluntary
can consciously control the muscle
involuntary
controlled subconsciously
self exciting
one muscle fiber is stimulated by a neuron which then stimulates other muscle fibers of the same type
rhythmic
contracts with a pattern
striations
appears striped as a result of filaments in the muscle tissue,needed for strength of contraction
histology of skeletal muscle
1.connective tissue,endomysium,epimysium,tendon/bone,perimysium,fascia
functions of skeletal muscle
movement,posture,stabilize joints,produce heat
skeletal muscle
organ,made of fascicles with connective tissue
fascicle
bundle of myofibers with connective tissue
muscle fiber or cell (myofiber)
contains cytoplasm,plasma membrane, and nuceli,made of myofibrils
myofibril
contractive unit of a myofiber,made of myofilaments
myofilament
sliding filaments made of proteins called actin and myosin
sarcolemma
plasma membrane
sarcoplasm
cytoplasm
sarcoplasmic reticulum
specialized smooth ER
sarcomere
contractile unit of a myofiber,"working unit" of myofibirl,distance
myofiber
striations,multinuclei
Z lines
discs, separate sarcomeres
A band
dark band, actin and myosin overlap with each other
I band
light band,just actin
actin
thinner myofilament
myosin
thicker myofilament
cross bridges
part of myosin filaments to attach to actin filaments
myofilament
found in myofibrils
motor unit
one motor neuron and all the myofibers it stimulates
neuromuscular junction
junction of a motor neuron and myofiber
motor neuron
causes the response
axon and axon terminals
end of the motor neuron
synaptic end bulb
the tips of the axon
synaptic vesicles
inside synaptic end bulb, hold the neurotransmitters
neurotransmitter
chemical messenger that carry impulses through the gap
synaptic cleft (gap)
space between a neuron and a myofiber
neurotransmitter receptors
a spot on the sarcolema (plasma membrane),receptor sites that receive neurotransmitters
impulse from motor neuron to myofiber
dendrites of motor neuron are stimulate causing polariz,depolariz,repolariz (action potential), Na+/K+ pump, action potential causes impulse to travel from dendrites,cell body,axon,axon terminals,synaptic end bulb,synaptic vesicles of motor neuron,synaptic vesicles release neurotransmitters(ACh), ACh travels across synaptic gap to ACh receptors on the sarcolemma of myofibers motor end plate
impulse in myofiber
sarcolemma of myofiber becomes permeable to Na+, Na+ enters sarcolemma and causes an action potential in the myofiber,acetyicholinesterase (AChesterose) degrades the ACh in the receptor sites after stimulus is received,action potential travels across surface of sarcolemma to S.R.,S.R. releases Ca+ which stimulates sliding filament theory
sliding filament theory in myofiber
Ca+ travels from S.R. through sarcoplasm to myofibril,Ca+ causes actin binding sites to open, myosin filaments cross bridges attach to binding sites on actin filaments,cross bridges "grab" onto open binding sites, when cross bridges grab binding sites, it causes sliding of the actin myofilament along myosin myofilament, sarcomeres of myofibrilic and all of myofbiers adn part of muscle shorten and contract
tetanus
continued contraction, no relaxation, effects are added, open wound, caused by a bacteria
muscle cramps
break down glucose without O2, produces too little ATP, lactic acid builds up and causes muscle fatigue, anaerobic
botulism
food poisoning in which bacteria toxin causes paralysis, dented cans
botox
bacteria from botulism, gets rid of wrinkles
stimulants
speed up impulses to neurons and muscle fibers, cocaine, speed, caffeine
depressants
slow down impulses, alcohol