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Anatomy muscles 2

Terms in this set (59)

Single mature muscle cell
Muscle fibers
Cardiac muscle cells are much ______ Than skeletal striated cells
Shorter
Even though cardiac muscles are short- they are also
Branched and interconnected. Producing long cardiac muscle fibers
Smooth muscle found is ____ layers
Thick
Smooth muscle also called
Visceral muscle
Skeletal muscle also called
Somatic muscle
Adjust volume of hollow organs
Smooth muscle
Extensibility =
The ability to stretch without tearing
During embryonic development, stem cells produce immature muscle cells called
Myoblast
Immature muscle cells
Myoblast
Each muscle fiber contains
Multiple nuclei
Adult muscle stem cells
Satellite cells
Satellite cells cannot
Divide
Satellite cells can be activated by
Exercise, injury, disease
Endomysium
Covers, insulates, supports, protects skeletal muscle fibers
Linear attachment/broad sheet (skeletal)
Aponeurosis
Somatic motor neuron
Carries signal in skeletal muscle
Cell bodies of motor neurons located in the
Brain or spinal cord
Brain/spinal cord send
Long cytoplasmic extensions called axons to communicate with muscle fibers
Motor unit comprises
Somatic motor unit + skeletal muscle
Visceral motor neuron
Carries similar signal to smooth muscle or glands
Branches that make contact with several muscle fibers
Axon terminals
chemical synapse
Neuromuscular junction
In response to action potential in presumptive cell
Neurotransmitter released in synaptic cleft. Then bonding to specific receptors on postsynaptic cell= electric activity
Action potential ______ results in action potential
Always
Every skeletal neuromuscular junction used the same
Neurotransmitters receptor
Neurotransmitter receptor =
Nicotine cholinergic receptor
NCR Redeptor is a _____ Gated ion channel
Logan's
Events at the Neuromuscular Junction step 1
Action potential stimulates ACh releases from synaptic bulb
Events at neuromuscular junction step 2
ACh binds with acerylcholinesterase to be degraded or bind to the nicotinic receptor
Events at neuromuscular junction step 3
ACh binding opens the channel Na+ enters and imitates action potential. Action potential spreads down the sarcolemma and tubles
Events at neuromuscular junction step 4
Action potential opens Ca2 gates in nearby sarcoplasmic reticulum Ca2 enters sarcoplasm
Signals can be
Electrical or chemical
Sequence of stimulating muscle (step 1)
Electrical signal in the somatic neuron
Stimulating muscle (step 2)
Chemical signal (ACh) in the synapse
Stimulating muscle (step 3)
Electrical signal in sarcolemma
Stimulating muscle (step 4)
Chemical signal (calcium) in sarcoplasm
Accomplish the work of muscle contraction
Myofibrils
Z disc of a myofibril
Found on either side of sacromere
sliding filament mechanism
Filaments sliding over each other
During muscle contraction- sacromeres and myofibrils shorten but myofilments don't
Change in length
Thin filaments are composed of 3 proteins
Actin, tropomyosin, troponin
Tropomyosin
Prevents myosin binding until a signal contraction arrives from nerve
Troponin
Controls tropomyosin molecules
Actin
Main constituent
Levels of skeletal muscle largest to smallest
Fasicle —-> muscle fiber —-> myofibril —-> myofilament —-> contractile protein
complete tetanus
Action potentials highest
twitch
Low action potential
incomplete tetanus
Action potentials waver high
Maximum sacromere length
Just right (100)
Property of muscle called the
Length tension relationship
isometric contraction
Muscle length does not change
concentric isotonic contraction
Muscle shortens
Eccentric isotonic contractions
Muscle lengthens
latch state
Cross bridge cycle ceases while actin and myosin remain bound together
Smooth muscle formed
3 diminseional cross cross structure
Cross cross non contractile
Intermediate filaments smooth muscle
Smooth muscle calcium acts on
Myosin not actin
prime mover
Muscle responsible for given moment
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