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77 terms

exam 3 phys 2

starts with notes pg 3 of muscle
STUDY
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myosin, actin, tropomyosin, troponin, 75%
what are the 4 primary components of skeletal muscle fiber? these proteins make up what percentage of muscle protein?
Titin
what is the protein that connects the myosin to the Z discs?
Titin
what is the protein that helps stabilize the centering of the myosin filaments in the sarcomere?
Nebulin
what is the elongated inelastic protein that is attached to the Z discs and spirals the actin myofilaments?
alpha-actinin
what is the protein that attaches actin filaments to the Z discs?
myomesin
what is the myosin binding protein that serves to hold thick myosin filaments in register at the M line?
C protein
what is the myosin binding protein that serves the same function as myomesin and forms several distinct stripes on either side of the M line?
sarcoplasmic reticulum, Ca2+
what is the ER of the muscle that generally lacks ribosomes called? has many __ pumps?
lateral sacs
terminal cisternae are also called what?
synapse
excitation-contraction: 1. excitation is initiated by ___
sarcolemma, T-tubules
excitation-contraction: 2. action potential propogates along __ and ____
Ca2+
excitation-contraction: 3. __ released by sarcoplasmic reticulum into sarcoplasm
troponin, troponin, tropomyosin
excitation-contraction: 4. ca2+ binds ___ causing cooperative configurational changes in __ and __. This exposes a myosin/G-actin binding site.
myosin, G-actin, myosin
excitation-contraction: 5. __/__ bind together? 6. this binding causes a conformation change in the __.
ADP, Pi
excitation-contraction: 7. the cocked myosin head/g-actin moves, constituting muscle contraction. As this movement of the myosin head occurs the __+__ are released?
ATP, ATP, G-actin
excitation-contraction: 8. the mvmnt causes conformational change in the myosin head exposing the __ binding site. __ binds to myosin. 9. This binding releases the myosin from the ___.
resting state
excitation-contraction: 10. The ATPase portion of the myosin head cleaves ATP: ATP=ADP+Pi. The myosin head uses that energy to "re-cock" for the next cycle. This configuration is considered to be in a __ __ regarding the myosin.
Rigor Mortis
without ATP, G-actin and myosin will remain bound. This is the major factor in what?
acetylcholine
synaptic vesicles contain what NT?
acetylcholine
motor end plate function: 1. nerve impulse reaching the terminal axon causes release of __
depolarization
motor end plate function: 2. acetylcholine binds to specific receptors on the sarcolemma which results in ___ of the latter. This is mediated by Na+ and K+ movement across the membrane.
T-tubules, TC+T+TC
motor end plate function: 3. the wave of depolarization spreads over the muscle cell and is propagated into the cell interior by ___. Depolarization of the triad (what are the 3 components of it) causes release of Ca2+ from the SR.
acetylcholinesterase
motor end plate function: 4. Released acetylcholine is broken down by what enzyme?
dihydropyridine receptors, foot proteins, Ca2+, dihydropyridine receptors, Ca2+
voltage sensitive proteins called ___ __ are in the cell membrane of the T-tubules. These receptors are connected to __ __, which are in the cell membrane of the terminal cisterna. Foot proteins are __ channels. When the T-tubules are depolarized, the __ __ change shape, which in turn stimulates the abutting foot proteins to open up, allowing __ to flow from the terminal cisterna into the cytosol.
actylcholinesterase
The SR possesses Ca2+-ATPase pumps which actively transport Ca2+ from the cytosol and concentrates it in the lateral sacs. Of course, this does not occur until the ACh is removed from the motor endplate by __
number of fibers stimulated and frequency of stimulation
contraction of a whole muscle can be of varying strength which is accomplished in two ways, what are they?
ventral, motor unit
NUmber of fibers stimulated: one motor neuron (in the dorsal/ventral horn) will supply several muscle fibers. That neuron plus all of the fibers it innervates is called a __ __. Those innervated fibers are spread throughout the muscle.
asynchronous recruitment of motor units
Muscles that are responsible for prolonged contraction such as back muscles have __ ___ __ __ __.
twitch summation
this occurs when 2 action potential fire rapidly enough such that the Ca2+ has not had enough time to be pumped out of the cytosol (where the troponin-tropomyosin is) back into the lateral sacs of the SR. called what?
tetanus
when fibers are maximally contracted. All binding sites are uncovered. called what?
isotonic, isometric
what are the 2 types of contraction?
concentric-muscle shortens, eccentric-muscle lengthens
what are the 2 types of isotonic contraction and describe them.
isotonic
the muscle tension remains constant as the muscle length changes is what type of contraction?
isometric
the muscle is prevented from shortening as muscle tension increases is what type of contraction?
creatine phosphate
__ __ is the first energy storehouse tapped at the onset of contractile activity
creatine-kinase
what enzyme catalyzes the change of creatine phosphate and ADP to creatine and ATP
creatine phosphate
sudden bursts of contraction will rely exclusively on ATP from __ __. ATP can be produced very rapidly from this source.
phosphagen energy system
the combined amount of muscle cell ATP and creatine phosphate is called the __ __ __.
mitochondria, 36, aerobic, cytosol
the citric acid cycle and the electron transport system, which occur in the __ . this process will yield __ ATP per glucose. It's a relatively slow process but is sufficient for energy supply during typical __ exercise. Glycolysis occurs in the __.
glycolysis, 2, pyruvic acid, lactic acid
if the activity of the muscle exceeds the amount of O2 needed then the muscle starts using __ for an ATP source. it yields __ ATP per glucose. the glucose is broken down to 2 __ __ molecules. they are further broken down to __ __. this process is quicker than the citric acid cycle and electron transport system though not as efficient in glucose use.
Psychological fatigue
the CNS no longer activates the motor neurons supplying the working muscles is known as what?
slow oxidative (type 1 fibers) and fast oxidative (type 2 A) fibers
what are the 2 types of red fibers? the fibers of a single motor unit are of the same muscle type.
fast glycolytic (type 2 B) fibers
what is the one type of white fibers?
atrophy
disuse of muscles will lead to what?
annulospiral
primary afferent fibers will have what type of endings?
flower spray
secondary afferent fibers will have what type of endings?
sphincter, GI tract
an example of tonic contraction is found in the __? phasic (rhythmic) is found where?
no
is smooth muscle attached to bone? y/n
gap junctions
to achieve the coordinated contraction, smooth muscle cells are connected by __ __.
actin, myosin, troponin complex
smooth muscle has __ and __ but does not have __ __.
6:1, 12:1
what is the actin/myosin ratio in skeletal muscle? smooth muscle?
creatine phosphate, glycogen
smooth muscle does not contain __ __ or __. it does not need those energy stores.
actin, myosin
in skeletal muscle, change occurs in the __ to effect binding. in smooth muscle, change occurs in the __
phosphorylated
myosin can't bind actin unless myosin is ___
calcium-calmodulin
calmodulin in the presence of calcium forms what?
active myosin kinase
inactive myosin kinase in the presence of calcium-calmodulin forms what?
phosphorylate myosin
inactive myosin in the presence of active myosin kinase forms what?
Ca2+ channels
calcium enters the cell of smooth muscle from the ECF via __ ___
Ca2+
__ is the major ion involved in depolarization in smooth muscle?
multiunit
which type of smooth muscle is found in the wall of large blood vessels, large airways to the lung, muscle of the eye, and erector pili muscles attached to hair
single unit
what is the most abundant of the smooth muscle in the body?
visceral smooth muscle
single unit smooth muscle is also called __ __ __.
single unit
which type of smooth muscle is found in the walls of hollow organs of viscera, digestive tract, reproduction and urinary tracts and small blood vessels?
myogenic activity
nerve independent contraction is called __ __
red, oxidative phosphorylation, long
slow oxidative (type 1) fibers: considered __ fibers. these are the slow twitching fibers. They get their ATP from __ __. Their fibers are used for ___ endurance types of contraction.
ATPases
There are 2 types of fast fibers, both of which contain higher levels of __ in the myosin enabling them to split ATP more quickly.
mitochondria, myoglobin
fast oxidative (type 2A fibers): these fibers are used for intermediate endurance types of contraction, both of the fast and slow oxidative fibers have large numbers of __ in them and also have the protein __. __, like Hb can bind O2. It acts like an O2 store and gives the fibers a reddish color.
white, glycolysis, glycolysis, mitochondria, glycogen, myoglobin
fast glycolytic (type 2B) fibers: considered _ fibers. these fibers get their ATP supply mostly from __. They are high in the enzymes necessary for __ and have few __. To supply the large amounts of glucose needed for the inefficient production of ATP there are large amounts of __ in this muscle fiber. They are the largest fibers bc they have a greater amount of actin and myosin. This enables them to produce tension that is more powerful for short amounts of time. They contain very little __ therefore are more pale in appearance.
mitochondria
aerobic ex will change the oxidative fibers by increasing the number of __ and capillary networking within the muscle.
diameter, hypertrophy
anaerobic exercise will inc the __ of glycolytic muscle fibers resulting in __. this will inc the power of contraction.
primary, secondary
__ synaptic cleft- indention of muscle. __ synaptic cleft- finer ridges mitochondria.
ATP, creatine phosphate
to repay the oxygen debt what levels have to be restored?
slow, fast
antigravity muscles will have a higher __ fiber content and muscles of the arms, a higher content of __ fibers.
bag, chain, intrafusal
neuromuscular spindle- sensory structure located in skeletal muscle, detects degree of tension in the muscle, functions as a strain gauge. the spindle consists of specialized muscle fibers--nuclear __ and__ fibers, collectively called the __ fibers.
extrafusal
extrafusal/intrafusal fibers have alpha motor innervation
tension, length, velocity, rate
the sensory receptor part of intrafusal fibers can sense ___, ___, __/__
shorter, longer
smooth muscle resting length is longer/shorter than skeletal muscle? myosin filaments are much longer/shorter than skeletal muscle.