missed questions Flashcards
what are conductance vessels
veins and arteries
characteristics of ___ circulation include lower pressures and resistance through the vessels
pulmonary
Maintaining homeostasis of the internal environment relies on which of the following (select all correct answers):
Maintaining adequate blood flow thought the tissue capillaries.
Optimizing the chemical composition of the blood for the interstitial fluid.
When a person becomes dehydrated, water is generally lost from the ________ compartment first.
interstitial
When looking at the cardiovascular system as a single unit, the pressure difference (∆P) across the system is the difference between
the aortic pressure and the right atrium pressure
In nodal/pacemaker cells, the diastolic potential is established by
K+ leaking out of the cell.
The Pacemaker Potential, also known as the Pre-Potential, in nodal cells is due to a reduction of _______ ions moving out of the cell and an increase in __________ moving into the cell through the HCN channel.
Potassium; Sodium
In Phase 3 of a fast response action potential, repolarization occurs with the opening of which type of channels?
Voltage-gated potassium delayed rectifier channels
Propagation of an action potential across the intercalated disc is due to _____________ through gap junctions.
the electrostatic attraction of ions
Sympathetic input has a positive chronotropic effect by increasing cell membrane permeability to (select all correct answers):
sodium and calcium
The resting tension on a cardiac myocyte is influenced by (select all correct answers):
preload and EDV
In addition to increasing the relaxation rate of cardiac myoctes, sympathetic input can shorten the absolute refractory period
by increasing cell membrane permeability to potassium via delayed rectifier channels.
Following the ejection phase, as a result of blood moving away from the heart
aortic pressure decreases.
The volume of blood ejected from the ventricles in relation to the starting volume is known as
ejection fraction.
An increase in downstream pressure (i.e. the pressure in the aorta) will result in ________. (select all correct answers)
a higher aortic valve closing pressure
a higher end-systolic pressure.
a higher aortic valve opening pressure.
An increase in preload _________
results in an increase in stroke volume.
is due to a higher end diastolic volume.
Cardiac output from the left ventricle is equal to
venous return
Which of the following factors does not directly influence stroke volume?
parasympathetic input
An increase in afterload results in
higher aortic valve opening pressure
lower stroke volume
higher aortic valve closing pressure
increased end-systolic pressure
The sodium-calcium exchanger
can move individual ions (i.e. sodium) in both directions across the cell membrane.
is dependent on concentration gradients
plays a role in resetting the membrane potential
High central venous compartment pressure leads to _________
a decrease in preload
an increase in stroke volume
pulmonary and systemic circulations that are in _____ with each other.
SERIES
Norepinephrine release from post-ganglionic neurons results in a positive ____________ effect at the SA node.
chronotropic
Which of the following depolarizes the resting membrane potential in a cardiac myocyte?
Inhibition of the Na+/K+ ATPase pump in the cell membrane (sarcolemma)
In ventricular myocytes, a negative lusitropic effect can result from
Inhibition of phospholamban.
