ch. 9 terms Flashcards
Muscles can transform ________ energy (ATP) into __________ energy, which is capable of exerting force for movement
chemical, mechanical
Myo and mys are prefixes for _________
Sarco means ________
muscle, flesh
Only skeletal and ________ muscle cells are elongated and referred to as muscle fibers
Cardiac muscle cells are called _____________
smooth, cardiocytes
_________ (skeletal/smooth) muscles are organs that are attached to ______ and skin, their fibers are striated, these muscles are __________
skeletal, bones, voluntary
Cardiac muscle tissue is found only in the _______ where it makes up bulk of heart walls
Cardiac muscle is _______ and _________
Cardiac muscle can _______ on its own with pacemaker cells and without nervous system stimulation
heart, striated, involuntary, contract
Smooth muscle tissue is found in walls of hollow v________ organs
Smooth muscle (is/ is not) _______ striated and is _________
Some Smooth muscle cells can ________ on their own with pacemaker cells and without nervous system stimulation
visceral, is not, involuntary, contract
- e___________ = responsiveness
The ability to receive and r________ to stimuli by changing the membrane potential - Contractility is the ability to s_______ forcibly when stimulated
- E__________ is the ability to be stretched beyond resting length
- Elasticity is the ability to r______ to resting length after stretching
excitability, respond, shorten, extensibility, recoil
Four important Muscle functions
1. Produce ________
2. ________ posture and body position
3. Stabilize _______
4. Generate ______ as they contract
movement, maintain, joints, heat
Skeletal muscle is an organ made up of different tissues
1. _______ muscle fibers
2. _____ fibers
3. _______ vessels
4. ___________ tissue sheaths
5. Attachments
skeletal, nerve, blood, connective
every ________ muscle fiber is supplied with a nerve ending that controls its ________
skeletal, activity
Contracting muscle fibers require
1. Continuous delivery of _____ and nutrients
2. e_______
O2, excretion
job of Connective Tissue Sheaths
1. s_________ muscle cells
2. r__________ and hold whole muscle together
support, reinforce
CT Sheaths from external to internal
1. ___mysium
2. _____mysium
3. ____mysium
epi, peri, endo
*Epimysium is dense ________ CT that surrounds the whole muscle
*Perimysium is f________ CT surrounding fascicles
*Endomysium is fine a______ CT surrounding each muscle fiber
irregular, fibrous, areolar
- _______ - attachment to movable bone
- ___________ - attachment to immovable or less movable bone
insertion, origin
With _______ attachments, the epimysium is fused to the
periosteum of bone
direct
*Sarco________ is the muscle fiber’s plasma membrane
*Sarco_____ is the muscle fiber’s cytoplasm
sarcolemma, sarcoplasm
m_________ are densely packed rod-like elements that account for ~80% of muscle cell volume and run the length of muscle fibers
Myofibrils
Myofibril s________ are stripes formed from repeating series of
dark and light bands along length of each myofibril
striations
Region of a myofibril between two Z discs is called a
s___________
sarcomere
m___________ myofilaments are thick filaments with myosin heads located
in the middle between Z discs
*Myosin is composed of p_______ myosin intertwined to form a myosin tail and forms the myosin globular head
myosin, protein
g____________ heads are the “business end” of myosin. During a
muscle contraction, myosin globular heads link myosin to actin
at actin’s active site forming c_______ bridges
Globular, cross
a_____ myofilaments are thin filaments with active sites anchored to
Z discs
actin subunits are link together to form long, fibrous strands
twisted together to form a thin f___________ like a “twisted string of
pearls”
actin, filament
t______________ molecules spiral around actin to stabilize it
tropomyosin
t_________ consists of three globular polypeptides and
calcium binds to __________
Troponin (x2)
e________ filament is composed of protein titin and hold
the thick filaments, myosin, in place
elastic
s____________ reticulum consists of
interconnecting tubules surrounding each myofibril
like a crocheted sleeve
sarcoplasmic
s______________ protrudes deep into the cell’s interior forming T tubules which are i__________ of the Sarcolemma
sarcolemma, invaginations
t_______ (another name for a piano chord) consist of a T tubule running between the paired terminal cisterns of SR
the Triad area formed is from 2 Terminal c______, T t______
triad, cisterns, tubule
s___________ occurs if the cross bridges generate enough tension on the thin filaments to exceed forces opposing shortening,
shortening
c____________ (pre/during labor) ends when cross bridges become inactive, tension declines, and the muscle fiber relaxes
contraction
in the r_________ state, thin and thick filaments overlap only slightly
relaxed
s_______ filament model of contraction states that during a c_________ the thin filaments slide past thick filaments causing actin and myosin to overlap more
sliding, contraction
Muscle Fiber c__________ is due to motor neuron stimulating s______ muscle fiber to contract
contraction, skeletal
Four steps must occur for skeletal muscle fiber to contract
1. n________ stimulation
2. a__________ potential = electrical current must be generated in sarcolemma
3. Action potential automatically propagated along s_______
4. Intracellular ______ levels must rise briefly
nerve, action, sarcolemma, CA2+
skeletal muscle cells are stimulated by s________ motor neurons
Parts of a Somatic Motor Neuron
1. Dendrites
2. ____ Body
3. Axons- long, threadlike extensions of motor neurons that travel
from _______ nervous system to skeletal muscle
4. terminal Branches- Each __________ branch gives off curling branches forming an elliptical neuro__________ Junction
5. Axon Terminals- the very end of the motor n_______ is the mound-like
somatic, cell, central, terminal, neuromuscular, neuron
s______ vesicles that contain the neurotransmitter
Acetylcholine
synaptic
ACh diffuses across cleft and ACh b______ with ACh r_______ on
sarcolemma of muscle fiber
binds, receptors
ACh is quickly broken down by the enzyme a____________________, which stops the contraction
acetylcholinesterase
Resting s_____________ is
p___________ which means a voltage exists across plasma
membrane
sarcolemma, polarized
An ____ plate potential (EPP) is a v_______ that causes the d________ of skeletal muscle fibers
end, voltage, depolarization
d___________ occurs when the inside of the cell becomes p_________ and outside the cell becomes n___________
depolarization, positive, negative
action potentials spreads across sarcolemma from one Na+ channel to next
one in adjacent areas causing that area to depolarize. This is
called s_________-p______________
self-propagating
r____________ is when the inside of the cell becomes n_________ and outside the cell becomes p__________
repolarization, negative, positive
During the r___________ period a muscle fiber cannot be stimulated again
until repolarization is complete
*Repolarization only restores the electrical conditions of a positive
charge on the ____________ of sarcolemma and a negative charge on _______ of the sarcolemma
refractory, outside, inside
Once an Action p_______ starts on muscle cell it is u unstoppable and results in the c___________ of a muscle fiber
potential, contraction
Excitation-Contraction Coupling are the events that t__________ AP along the sarcolemma
*With (E-C) coupling, an AP is propagated along s______________
transmit, sarcolemma
c__________ bridge formation occurs when a high-energy myosin head
attaches to the a_____ active site
*In the p________ stroke, the myosin head pivots and pulls thin filament
(actin) toward middle of the sarcomere
*Cross bridge d____________ results when ATP attaches to myosin
head, causing the cross bridge to detach
*c__________ of myosin head occurs when ATP “cocks” myosin head into
high-energy state
cross, actin, power, detachment, cocking
m________ unit is the nerve-muscle functional unit
motor
When a Motor unit transmits an AP, all the muscle fibers it
innervates c____________ simultaneously
contract
in a s________ Motor Unit, the motor neuron can supply a few muscle cells
*Smaller motor units result in control that is more p_________.
In a l_______ Motor Unit, the motor neuron can supply several hundred muscle
cells
*Larger motor units produce greater f_______
small, precise, large, force
Muscle t_____ occurs when a muscle fiber c______ quickly and then relaxes
twitch, contracts
i___________ Muscle Twitch is not strong enough to do any useful work
because it is rapid and brief
individual
Muscle contractions are graded in two ways by changing
1. f___________ of stimulation = wave summation
2. s________ (gym)
3.of stimulation = recruitment of motor units
frequency, strength
The nervous system achieves a greater m__________ force by increasing the frequency of the firing rate of the motor n_______
muscular, neurons
____ _________ occurs when stimulations are quickly delivered to a muscle fiber before it relaxes
wave summation
r______________ is the result of change in stimulus strength
Recruitment controls the f_____ of contraction
1. By calling more and more m____ fibers into play
2. By calling more and more m______ units into play
recruitment, force, muscle, motor
s___________ stimulus, the stimulus is not strong enough so no contractions are seen
*With a t__________ stimulus, the stimulus is strong enough to
cause the first observable contraction
*m__________ stimulus is the strongest stimulus and increases
maximum contractile force as all motor units have been
recruited
subthreshold, threshold, maximal
in i___________ contractions, muscle contraction moves the load with the
same tension (actin slides past myosin)
Isotonic
c_____________ contraction, the muscle shortens and does
work.
e___________ contraction, generates force as it lengthens
concentric, eccentric
In i____________ contractions, the load is greater than the maximum tension the muscle can generate so the muscle neither shortens nor lengthens (cross bridges generate a force but do not move
actin filaments)
isometric
Creatine phosphate is a unique h_____ energy molecule
Creatine phosphate is located in m_______ fibers and donates phosphate to A__P to form A__P
high, muscle, D, T
v_______ exercise alters muscle chemistry for a muscle to return to its pre-exercise state
vigorous
Force of Muscle Contraction is affected by four factors
1. n_______ of muscle fibers stimulated
2. Relative s_____ of fibers
3. f_______ of stimulation
4. d________ of muscle stretch
number, size, frequency, degree
If muscles are maintained at optimal resting length, muscles c________
with greater f________
contract, force
How fast they can contract = v________
How long they can continue to contract before they fatigue = d________
velocity, duration
o___________ fibers = aerobic pathways
glycolytic fibers = a___________ glycolysis
oxidative, anaerobic
g__________ dictate individual’s percentage of slow oxidative fibers, fast
oxidative fibers, or fast glycolytic fibers
genetics
s_____ oxidative fibers function in low-intensity, endurance type activities
f__________ oxidative fibers function in medium-intensity activities
Fast g__________ fibers function in short-term intense, powerful movements
slow, fast, glycolytic
Muscles contract f_______ when no load is added
fastest
With r____________, (military) more motor units are contracting and result in a faster and longer contraction
recruitment
a__________ Exercise leads to increased
1. Muscle capillaries
2. Number of mitochondria
3. Myoglobin synthesis
*So aerobic (Endurance) Exercise results in greater
1. e_________
2. s__________
3. r_______ to fatigue
aerobic, endurance, strength, resistance
Resistance exercise (typically anaerobic) such as weight lifting or isometric exercises leads to muscle h__________ and leads to Increased
1. m_______________
2. Myofilaments
3. Glycogen stores
4. c___________ tissue
5. Muscle strength
6. m__________ size = muscle fiber diameter
hypertrophy, Mitochondria, connective, muscle
Disuse a_________ is the d_____________ and loss of muscle mass
1. Due to i__________
2. Due to loss of neural s____________
atrophy, degeneration, immobilization, stimulation
Smooth Muscle is found in walls of most hollow organs except h______
(hollow organ)
heart
Smooth Muscle in Walls of
1. r______ tract
2. d________ tract
3. u__________ tract
4. r________ tract
5. Blood Vessel - All but smallest blood vessels contain smooth
muscle: capillary no smooth muscle
respiratory, digestive, urinary, reproductive
*In the l____________ layer of Smooth Muscle, fibers run parallel to
long axis of the organ and contraction causes the organ to shorten
*In the c___________ Layer of Smooth Muscle, fibers run around
circumference of the organ and contraction causes constriction of
the lumen
Longitudinal, Circular
peristalsis is when alternate c_______ and relaxations of the layers m___ and squeeze substances through l_________ of hollow organs
contractions, mix, lumen
v______________ are bulbous swellings that store and release neurotransmitters into wide synaptic clefts (diffuse junction)
Varicosities
actin attaches (directly/indirectly) to the z disc and is (thick/thin) filament
directly, thin
myosin is attached (directly/indirectly) to z disc by (tritin/titin) and is the (thick/thin) filament that had (globe/globular) heads
indirectly, titin, thick, globular
the ___________ _____________ surrounds the myofibrils
sarcoplasmic reticulum
*With _________ attachments, the connective tissue wrappings extend
beyond muscle as
1. If Ropelike it’s = _____
2. If Sheet-like it’s= ______________
indirect, tendon, aponeuroses
what is the name for the physiological ability to contract, even though the muscle still may be receiving stimuli and occurs when there are ionic imbalances (high levels of calcium, phosphate, and salt)
muscle fatigue
which vertebral component is the largest
lumbar
during a contraction what happens?
sarcomere shortens and actin and myosin overlap
The end product of anaerobic respiration is (glucose and acid)
glycolysis and lactic acid
the end product of aerobic respiration is
ATP
direct phosphorylation produces
new ATP molecules
EPOC stands for and represents what
Excessive PostExercise Oxygen Consumption
amount of oxygen needed for aerobic activity-amount of oxygen actually used
Fontinelles connect ______ bones
skull
what is a motor unit (equation)
motor neuron + muscle involved
what must be present for a sliding filament to work?
Ca2+ (calcium)
parts of the pubic area
iliac crest, ilium, ischium
