Unit 3 - A & P Module - Introduction to Cardiac and Smooth Muscle Flashcards
What triggers contraction in smooth muscle?
Calcium binds to calmodulin.
Put the following in order of largest to smallest:
a. myofibril
b. muscle fiber
c. fascicle
d. thick filament
c, b, a, d
In what way(s) is cardiac muscle similar to smooth muscle
It contains gap junctions, it possesses pacemaker cells, and it is innervated by autonomic neurons.
Which is the fastest way that a skeletal muscle cell can generate ATP to power muscle contraction?
The high-energy phosphate on the creatine phosphate (phosphocreatine) is transferred to ADP creating more ATP.
Which of the following statements is true about smooth muscle?
Actin and myosin generate force through the crossbridge cycle.
Which of the following have a large muscle fiber diameter and a high force-generating capacity?
White, fast glycolytic fibers
Which of the following statements is true?
The thin and thick filaments in smooth muscle have an oblique arrangement.
During skeletal muscle contraction, thick and thin filaments bind together forming __________.
crossbridges
Molecules common to both skeletal and smooth muscle crossbridge cycling include __________.
actin
In smooth muscle, the release of calcium from the sarcoplasmic reticulum is regulated by __________.
all answers are incorrect
The generation of a smooth, steady, maximum tension contraction by a muscle fiber, with no evidence of relaxation, due to a very rapid stimulation of the muscle fiber is known as __________.
complete (fused) tetanus
The burning sensation that is felt in muscles during exercise is due to the buildup of __________.
lactic acid
Smooth muscle is similar to skeletal muscle in which of the following ways?
Both possess actin and myosin
When a muscle is stimulated at a high frequency such that the twitches build on each other, __________ is observed.
summation
Which of the following statements is true?
Eccentric contractions perform a lengthening action.
In which type of muscle is the function of gap junctions of the greatest importance in maintaining life?
Cardiac
An increase in the force generated by a muscle is achieved by the __________ of more motor units.
recruitment
Which of these statements about smooth muscle is true?
There are two types: multi-unit, which lacks gap junctions, but has dense innervation; single-unit, which does have gap junctions, but sparse innervation.
What terminates smooth muscle contraction?
Dephosphorylation of myosin by a phosphatase
The amount of force a muscle can generate depends on __________.
the number of sarcomeres in parallel, the length of individual sarcomeres, and the cross-sectional diameter of the muscle fibe
Which type of muscle is subject to the greatest diversity of hormonal control?
Smooth muscle
Which muscle fiber type experiences slow-wave potentials?
Smooth muscle
Thick and thin filaments overlap within the __________.
A band
There is a high degree of overlap between the action potential and the contractile response in cardiac fibers. Why?
The overlap prevents summation of cardiac muscle contractions; it is critical that the heart have time to relax and fill with blood before the next contraction.
