muscle tissue
What energizes the myosin head?
ATP hydrolysis reaction
Why do you think that a healthy 30-year-old can lift a 25-pound weight much more comfortably than a healthy 80-year-old?
All of the choices are correct.
Which statement explains the sarcomere appearance change during a muscle contraction?
The h zone shortens as actin filaments slide towards the m-line.
A runner nearing the end of a marathon race would produce most ATP by:
aerobic respiration.
The opening of ligand gates on the sarcolemma is directly caused by
all choices are correct
In which of the following do skeletal muscle and cardiac muscle differ?
all of the choices are correct
Muscle fibers produce ATP using:
all of the choices are correct.
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
Which correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction?
axon of neuron, sarcolemma, T tubules
Smooth muscle tone is maintained by the prolonged presence of [_____] in the muscle cell's cytosol?
calcium ions
Contraction of myofibrils within a muscle fiber begins when
calcium is released from the sarcoplasmic reticulum
Skeletal and smooth muscle differ in all of the following EXCEPT:
contraction mechanism.
The zone of overlap increases during the
contraction period
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
World class shot-putters will have a higher percentage of ______in their arm muscles.
fast glycolytic fibers
Strength training would result in
hypertrophy of fast oxidative-glycolytic fibers
Motor unit recruitment occurs when there is a(n) _________ in the number of active motor units within a skeletal muscle.
increase
Which function do all three muscles perform?
moving and storing material throughout the body
Which disorder occurs when little to no proteins are produced to support the sarcolemma?
muscular dystrophy
Which of the following molecules found in skeletal muscle cells binds oxygen that can later be used during aerobic metabolism to help generate ATP?
myoglobin
Muscle damage can be indicated by...
myoglobin found in blood.
Which functions as a motor protein in all three types of muscle tissue?
myosin
Visceral and multiunit smooth muscle differ in:
number of gap junctions present
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.
Which type of muscle tissue is capable of undergoing the stress-relaxation response when stretched?
single-unit smooth muscle fibers
Why will an individual who lifts weights build larger muscles?
skeletal muscles increase number of myofibrils but not number of cells
As Marie rounded the corner, she saw that people were already boarding her bus. Worried that she would miss her ride to campus, she sprinted to the bus stop. In what order were skeletal muscles recruited during her sprint?
slow oxidative, fast-oxidative glycolytic, fast glycolytic
Which characteristics describe both skeletal and cardiac muscle?
striations
The contractile organelle of skeletal muscle fibers is
the myofibril
What is the result of acetylcholine attaching to the ligand gates of the motor end plate?
the sarcolemma increases permeability to sodium
________ released from the sarcoplasmic reticulum bind to troponin to trigger exposure of binding sites on actin and begin the contraction cycle. ______ supplies energy to detach the myosin head from actin.
Calcium ions; ATP
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
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
Which of the regions of a sarcomere contain titin?
From M line to Z disc
When athletes are preparing to perform a pull up, they hang from the bar. At this point, they are performing what type of contractions?
Isometric
Mitochondrial activity in skeletal muscle cells are usually efficient, but can have limited ATP production if
Mitochondrial activity in skeletal muscle cells are usually efficient, but can have limited ATP production if
