Medical Physiology PHSL 1010: Exam 2| Ques ons and
answers | Updated RATED A+
T-tubules (triads)
Depolarizing currents pass to the sarcoplasmic re culum via:
Troponin
The muscle protein that binds to Ca++ during excita on-contrac on coupling is:
One muscle cell only
A skeletal muscle fiber comprises:
Slow-twitch fibers have more myoglobin than fast-twitch AND Slow-twitch fibers are more
fa gue-resistant than fast-twitch
Fast-twitch muscle fibers differ from slow-twitch fibers in which way(s)?
Smooth muscle cells have only one nucleus AND Smooth muscle contracts more slowly than
skeletal muscle
Smooth muscle differs from skeletal muscle in which way(s)?
Z lines (from striated [cardiac & skeletal] muscles)
Smooth muscle dense bodies perform a similar func on to:
Inside sheets of smooth muscle
Parasympathe c ganglia that aid in control of smooth muscle contrac on are located:
Ca++ enters the cell, Ca++ binds to calmodulin, myosin heads are phosphorylated, myosin binds
to ac n
The correct sequence of events in smooth muscle contrac on is:
Cardiac muscle cells have only one nucleus and are branched
Cardiac muscle differs from skeletal muscle in which way(s)?
Both serve as the inser on point for cardiac muscle cells and contain numerous gap junc ons
and desmosomes
Intercalated disks:
, Is both limited by parasympathe c ac vity and is similar to that seen in skeletal muscle
Excita on-contrac on coupling in cardiac muscle:
Are characterized by a broad plateau as Ca++ enters the cell
Ac on poten als in cardiac muscle cells:
Gap junc ons
Depolarizing signals pass through the atrial musculature via:
Closure of the mitral valve AND Closure of the tricuspid valve
The first "heart sound" is made by:
Atrial diastole
The greatest blood pressure is achieved at:
Anchor the leaflets of the A-V valves AND Are inserted into the ventricular musculature
Papillary muscles:
Varies with heart rate (and stroke volume)
Cardiac output:
Achieves maximum force when muscle fibers are stretched AND Achieves maximum force when
end diastolic volume is greatest
The Frank-Starling Law of the Heart shows that cardiac muscle:
Can be enhanced by catecholamines
Contrac lity of the heart:
Arteries have more elas c fibers in the tunica media than veins
Arteries differ from veins in which way?
Cardiac output and arterial resistance
Mean arterial pressure is directly propor onal to:
Is affected by stress, emo on, epinephrine, and by sympathe c s mula on
Arterial resistance:
Affects blood pressure by altering blood volume AND Is ini ated by sensors in the macula densa
of the kidney.
answers | Updated RATED A+
T-tubules (triads)
Depolarizing currents pass to the sarcoplasmic re culum via:
Troponin
The muscle protein that binds to Ca++ during excita on-contrac on coupling is:
One muscle cell only
A skeletal muscle fiber comprises:
Slow-twitch fibers have more myoglobin than fast-twitch AND Slow-twitch fibers are more
fa gue-resistant than fast-twitch
Fast-twitch muscle fibers differ from slow-twitch fibers in which way(s)?
Smooth muscle cells have only one nucleus AND Smooth muscle contracts more slowly than
skeletal muscle
Smooth muscle differs from skeletal muscle in which way(s)?
Z lines (from striated [cardiac & skeletal] muscles)
Smooth muscle dense bodies perform a similar func on to:
Inside sheets of smooth muscle
Parasympathe c ganglia that aid in control of smooth muscle contrac on are located:
Ca++ enters the cell, Ca++ binds to calmodulin, myosin heads are phosphorylated, myosin binds
to ac n
The correct sequence of events in smooth muscle contrac on is:
Cardiac muscle cells have only one nucleus and are branched
Cardiac muscle differs from skeletal muscle in which way(s)?
Both serve as the inser on point for cardiac muscle cells and contain numerous gap junc ons
and desmosomes
Intercalated disks:
, Is both limited by parasympathe c ac vity and is similar to that seen in skeletal muscle
Excita on-contrac on coupling in cardiac muscle:
Are characterized by a broad plateau as Ca++ enters the cell
Ac on poten als in cardiac muscle cells:
Gap junc ons
Depolarizing signals pass through the atrial musculature via:
Closure of the mitral valve AND Closure of the tricuspid valve
The first "heart sound" is made by:
Atrial diastole
The greatest blood pressure is achieved at:
Anchor the leaflets of the A-V valves AND Are inserted into the ventricular musculature
Papillary muscles:
Varies with heart rate (and stroke volume)
Cardiac output:
Achieves maximum force when muscle fibers are stretched AND Achieves maximum force when
end diastolic volume is greatest
The Frank-Starling Law of the Heart shows that cardiac muscle:
Can be enhanced by catecholamines
Contrac lity of the heart:
Arteries have more elas c fibers in the tunica media than veins
Arteries differ from veins in which way?
Cardiac output and arterial resistance
Mean arterial pressure is directly propor onal to:
Is affected by stress, emo on, epinephrine, and by sympathe c s mula on
Arterial resistance:
Affects blood pressure by altering blood volume AND Is ini ated by sensors in the macula densa
of the kidney.
