In the diagram, calcium ions will rush into this area.
B
Which type of muscle tissue contracts when excited by their own autorhythmic muscle fibers?
cardiac muscle
Which age group would be most susceptible to an increase in slow oxidative muscle fibers?
30+ years
Which of the regions of a sarcomere contain titin?
from M line to Z disc
What is the result of acetylcholine attaching to the ligand gates of the motor end plate?
The sarcolemma increases permeability to sodium
Smooth muscle tone is maintained by the prolonged presence of [_____] in the muscle cell’s cytosol?
calcium ions
All of the muscle fibers within the muscle are fully contracted and are in sustained contraction with no individual twitches detected due to high frequency of stimulation.
D
Which of the following structures are made of dense regular connective tissue?
A
Which region of a sarcomere contain thin filaments?
Both I band and A band.
In the diagram, which structure(s) moves towards the center of the sarcomere (closer together) when the fiber contracts?
A
At the neuromuscular junction, _______must enter the synaptic end bulb to stimulate the release of ____________, which binds to ligand gates so ________can enter the muscle fiber.
calcium ions; ACh, sodium ions
When athletes is preparing to perform a pull up, they hang from the bar. At this point, they are performing what type of contractions?
Isometric
For the muscle to contract and relax, what must be present (choose all that apply)?
ATP
Calcium ions
ACh
Writer's cramp can occur in Anatomy and Physiology lecture class. What factor would most likely contribute to the muscles not being able to relax?
a deficit of ATP keeping myosin from detaching
Which type of muscle tissue is capable of undergoing the stress-relaxation response when stretched?
single-unit smooth muscle fibers
Muscle damage can be indicated by…
myoglobin found in blood.
Which term describes a somatic motor neuron and all the skeletal muscle fibers it stimulates?
motor unit
The relaxation phase of a muscle contraction is often prolonged in a fatigued muscle, raising the likelihood of fused summation of action potentials causing painful disturbances to a skeletal muscle. What disturbance is being described?
Cramp
Which microscopic structure is found only in the cardiac muscle tissue?
intercalated discs
Myofibrils contain what type of proteins? Select all that apply.
contractile proteins
regulatory proteins
structural proteins.
Place the muscle tissue type in order from least to most ability to regenerate.
skeletal, cardiac, smooth
What energizes the myosin head?
ATP hydrolysis reaction
Motor unit recruitment occurs when there is _______ in the number of active motor units within a skeletal muscle.
Increase
In the diagram, where would you find stored Ca2+?
F
On the diagram, which layer is composed of dense irregular connective tissue and surrounds the entire muscle.?
C
Which statement explains the sarcomere appearance change during a muscle contraction?
The light A bands remain at a constant length.
During muscle contractions , thin filaments are pulled towards the
M line
What proteins are found in thin filaments of skeletal muscle fibers? Select all that apply
tropomyosin
myosin
actin
nebulin
Strength training would result in
hypertrophy of fast oxidative-glycolytic fibers
Which characteristics describe both skeletal and cardiac muscle?
Striations
The outermost layer of connective tissue surrounding a skeletal muscle is the
Epimysium
A brief contraction of all muscle fibers in a motor unit in response to a single action potential moving down the somatic motor neuron is known as
twitch contraction.
In the diagram, what structure contains motor proteins that convert the energy in ATP into mechanical movements?
C
In skeletal muscles, the combined amounts of creatine phosphate and ATP provide enough energy for the muscle to contract maximally for approximately
15 seconds
After prolonged strenuous exercise has stopped, heavy breathing will often continue for several minutes in order to provide the oxygen needed to
all of these choices are correct
In the diagram, how do action potentials penetrate the outside of the muscle fiber? .
D
Which correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction?
axon of neuron, sarcolemma, T tubules
Which regions of the sarcomere contain thick filaments? Select all that apply.
zone of overlap
A band
H zone
Which portion of this myogram shows a single twitch of the muscle?
A
The zone of overlap increases during the
contraction period
On the diagram, a tendon is formed by the merging of which structures?
C, D, and H
Myasthenia Gravis is an autoimmune disorder that targets the ACh receptors at the NMJ and ultimately reduces the number of available receptors. Predict what happens if you treat the patient with a drug that inhibits the activity of acetylcholinesterase?
The drug will increase contraction.
In the diagram, where are troponin, tropomyosin and nebulin located?
B
In the diagram, what area is composed of only thick filaments?
D
Leg muscles are predominantly composed of which type of muscle fiber?
fast oxidative-glycolytic
Diltiazem is a calcium channel blocker, reducing free intracellular calcium. What stage of the myogram would be affected immediately?
Latent period
Which function do all three muscles perform?
Moving and storing material throughout the body
In the diagram, acetylcholine is released from ____ and diffuses to _____.
B; E
Which functions as a motor protein in all three types of muscle tissue?
Myosin
Thapsigargin is a potent calcium ATPase pump inhibitors. What state of the myogram would be affected immediately?
Relaxation period
Why would cardiac muscles have longer refractory periods than skeletal muscles. Choose the best answer?
to preserve the normal rhythm of the heart and prevent fatigue
In the diagram, which structure helps return a stretched sarcomere to its resting length?
E
Which disorder occurs when little to no proteins are produced to support the sarcolemma?
muscular dystrophy
When an athlete performs a pull up (raising their chin to a bar while their body hangs), the process of pulling the body up so the chin can touch the bar is
Concentric
Contraction of myofibrils within a muscle fiber begins when
calcium is released from the sarcoplasmic reticulum
In a neuromuscular junction, the effect of acetylcholine (ACh) binding to receptors on the motor end plate lasts only briefly due to
rapid destruction of ACh in the synaptic cleft by acetylcholinesterase.
. Skeletal muscle contraction is triggered to begin when calcium is released from
terminal cisterns of sarcoplasmic reticulum
Which ATP production would be sufficient to run in place for one minute?
anaerobic cellular respiration
After the fusion of myoblasts, the muscle fiber loses its ability to
go through mitosis
When an athlete performs a pull up (raising their chin to a bar while their body hangs), the process of lowering the body down is
Eccentric
Mitochondrial activity in skeletal muscle cells are usually efficient, but can have limited ATP production if
there is limited O2 availability
On the diagram, what structure is composed of the three connective tissue layers that extend past the muscle?
A
Which protein is used to reinforce the sarcolemma and help transmit the tension generated by the sarcomeres to the tendons?
dystrophin
Why will an individual who lifts weights build larger muscles?
skeletal muscles increase number of myofibrils but not number of cells
Which property of muscle gives it the ability to stretch without damage?
Extensibility
Cross bridges are formed during muscle contraction when _____ binds to _____.
myosin; actin
The opening of ligand gates on the sarcolemma is directly caused by
all choices are correct
In the diagram, what area contains both thick and thin filaments?
H
For crossbridges to occur, what events must happen? Select all that apply.
ATPase breaks down ATP
Calcium ions be present in the sarcoplasm
Myosin binding sites be exposed.
World class shot-putters will have a higher percentage of ______in their arm muscles.
fast glycolytic fibers