Chapter 9 A&P
The sliding filaments model of contraction involves
Actin and myosin sliding past each other and partially overlapping
Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped___
No muscle tension could be generated
An anaerobe metabolic pathway that results in the production of two net ATPs per glucose plus two pyrvic acts molecules is
glycolysis
Creating phosphate functions in the muscle cell by
storing energy that will be transferred to ASP to resynthesizes to ATP
Which of the following statement is true
striated muscle cells are long and cylindrical with many nuclei
The mechanism of contractions in smooth muscle is different from skeletal muscle in the______
The site of calcium regulations differs
Which of the following describes the cells of single--unit visceral muscle
They exhibit spontaneous actions potential
The gains protein titian maintains the organizations of the____ assisting in muscle
A band
Excitations-contractions coupling requires which of the following substance
Ca 2+ and ATP
Immediately following the arrival of the stimulus at a skeletal muscle cell there is short period called the ______ period during which the events of excitations--contractions coupling occur
Latent
Which of the following statement is most accurate
Muscle tension remains relatively constant during isotonic contractions
The muscle cells membrane is called the
Sarcolemma
What structure in skeletal muscle cells functions in calcium storage
Sarcoplasmic reticulum (SR)
Myoglobin
Stores oxygen in muscle cells
What is the most distinguishing characteristics of muscle tissue
The ability to transform chemical energy into mechanical energy
What produced the striations of a skeletal muscle cell
The arrange,ent of myofilaments
What does oxygen deficit represent
The difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used.
What is the role of tropomyosin in skeletal muscles
Tropomyosin serves as contractions inhibitor by blocking by blocking the myosin binding sites on the actin molecules.
Three discrete types of muscle fibers are identified on the basis of their size, speed and endurance. Which of the of the following athletic endeavors best represent the use of red fibers?
a long, relaxing swim
Most skeletal muscles contain
a mixture of fiber types
What is the functions unit of a skeletal muscle called
a sarcomere
The term aponeurosis refers to
a sheetlike indirect attachment to a skeletal element
Muscle tone is
a state of sustained partial contractions
After nervous stimulations stopes, what prevents ACh the synaptic cleft from connoting to stimulate contractions
acetylcholinesterase destroying the ACh
during muscle contractions, myosin cross bridges attach to which active sites
actin filaments
Which of the following is not a role of ionic calcium in muscle contractions
activates epinephrine release from adrenal gland
What is the role of calcium ions in muscle contractions
bind to regulatory sites on troponin to remove contractions inhabitation
Which of the following statement is false or incorrect
cardiac muscle fibers depend mostly on anaerobic cellsuerl respirations to generate ATP
Which of the following is true about smoothie muscle contractions
certain smooth muscle cells can actually divided to increase their numbers
In an isotonic contractions the muscle
changes in the length and moves the "load"
Which of the following is not a way muscle contractions can be graded
changing the type of muscle fibers involved in the contractions
Which of the following surrounds the individual muscle cell
endomysium
What is the functional role of the T tubules
enhance cellular communications during muscle contraction
The main effect of the warm-up period of athletes as the muscle contractions increase in strength, it to
enhance the availability of calcium and the efficiency of enzymes system
Which of the following is not a usual result of resistance exercise
increase in the number of muscles cells
Which of the choices below does not describe how recovery oxygen uptake (oxygen deficit)
increase the level of lactic acid in the muscle
The strongest muscle contractions are normally achieved by
increasing the stimulations up to the maximal stimulus
Fatigued muscle cells that recover rapidly are the products of
intense exercise of short duration
During vigorous exercise, there may be insufficient oxygen available to completely break down pyretic acid energy. As a result, the pyruvie acid is converted to
lactic acid
Which of the following is a factor that affects the velocity and duration of muscle contractions
load on the fiber
What part of the sarcolemma contains acetylcholine receptors
motor end plate
which of the following is the correct sequences of events for muscle contractions
motor neuron actions potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP--driven power stroke, sliding of myofilaments.
Which of the following would be recruited later in the muscle stimulations when contractile strength increase
motor unties with larger, less excitable neurons
What controls the force of muscle contraction
multimotor unit summations
Smooth muscles that act like skeletal mescals but are controlled by autonomic nerves and hormones are________
multiunit muscles
Of the following muscle types, which had only one nucleus, o sarcomeres and rare gap junctions
multiunit smooth muscle
The contractile units of skeletal muscles are
myofibrils
The oxygen--binding protein found in muscle cells is____
myoglobin
Rigor mortis occurs because
no ATP is available to release attached actin and myosin molecules
When a muscle is unable to respond to stimuli temporarily it is in which of the following periods
refractory period
The major functions of the sarcoplasm reticulum in muscle contractions is to
regulate intracellular calcium concentration
muscle tissue had all of the following properties except
secretion
Which muscle cess have the greatest ability to regenerate
smooth
Smooth muscle is characterized by all of the following expect
there are more thick filament than thin filaments
Which of the following are compose of myosin
thick filaments
The warm-up period required of athletes in order to bring their muscle to perk performance is called_____
treppe