PHYSIOEX Lab 5 Excercises 1-7 Flashcards
total blood flow is determined by
cardiac output
three main factors that affect resistance are
blood vessel radius
blood vessel length
blood viscosity
the smaller the blood vessel radius the _______ the _________
greater the resistance
define vasoconstriction
contraction of smooth muscle of the blood vessel
vasoconstriction results in the
decrease in the blood vessel radius
define vasodilation
relaxation of smooth muscle of the blood vessel
vasodilation causes
the increase in the blood vessel radius
T/F: blood vessel radius is the single most important factor in determining blood flow resistance.
TRUE
longer the vessel length, the ____________
greater the resistance
define viscosity
blood thickness and determined by hematocrit - the fractional contribution of red blood cells to total blood volume
the higher the hematrocrit, the ___________
greater the viscosity
Q: blood flow is measured in;
ml/min
Q: Which of the following has the greatest effect on blood flow
blood vessel radius
Q: which of the following would not result in a decrease in the blood vessel radius
vasodilation
Q; the diameter of the blood vessel is the same as
two times the radius of the blood vessel
Q: the opening of the blood vessel where the blood flows is called the
lumen
viscosity is
the thickness or stickiness of a fluid.
the viscosity of blood is due to
the presence of plasma proteins and formed elements which include white cells, red blood cells and platelets
what is polycythemia
a condition in which excels red blood cells are present, and certain types of anemia result in fewer red blood cells
Q: which of the following is not a formed element
plasma protein
Q: thrombocytopnia is a reduction in platelets. what effect do ou think this could have on blood viscosity
decrerase blood viscosity
Q: which of the following does not contribute to the viscosity of the blood
oxygen level in blood
Q: viscosity most directly affects
peripheral resistance
the longer the vessel, the ________________ the resistance to blood flow through the blood vessel
greater
if you gain weight, the blood vessel will
increase in length
if you lose weight the blood vessel will
decrease in length
Q: when the length of the blood vessel increases, which of the following increases
both friction and surface area
Q: blood vessel length decreases when
we lose wegith
Q: blod flow is
directly proportional to vessel radius to the fourth power
Q: which of the following correctly describes resistance to flow:
resistance to flow increases with increased vessel length
for the force of contraction of the heart provides
the initial pressure
vascular resistance contributes to
the pressure gradient
Q: pressure changes in the cardiovascular system primarily result from
changes in the force of contraction of the heart
Q: what is the driving force for blood flow
pressure gradient
Q: which of the following is directly proportional to blood flow
blood vessel radius and pressure gradient
Q: arteries close to the heart need to be able to compensate for
pressure changes
each heartbeat consists of what two things
filling interval - blood moves into the chambers of heart
ejection period - when blood is actively pumped into the aorta and the pulmonary trunk
define diastole
relaxation of heart
define systole
contraction of the heart
heart chambers fill during _______
diastole
heart chambers pumb blood out during _______
systole
_________ side of the heart pumps blood through the lungs into the ___________
right side
left side
__________ side of the heart delivers blod to the systems of the body
left
blood returns to the _______ side of the heart to complete the circuit
right
T/F: to maintain blood pressue, the cardiovascular system can alter heart rate, stroke volume or resistance
TRUE
Q: the heart is resting during
ventricular diastole
Q: the right side of heart pumps blood to
lungs
Q: the layer of the blood vessel that is stimulated by the autmatic NS is the
smooth muscle
Q: in the experiment, the pump stimulates
left ventricle of the heart
Q: if the right beaker stimulates the flow of blod to the systemic circuit of the body, what do the right valve and flow tube represent
aortic valve and aorta
what factors affect stroke volume
preload,
contractility
afterload
define preload
degree to which the ventricles are stretched by the end diastolic volume
when the end diastolic volume increases, the cardiac muscle fibers of the ventricles
stretch and lengthen
define afterload
the back pressure generated by the blood in the aorta and pulmonary trunk. this is the threshold that must be overcome for the aortic and pulmonary semilunar valves to open
define cardiac output
equal to the heart rate multipled by the stroke volume.
in cardiac output when the stroke volume decreases, the heart rate must
increase to maintain cardiac output.
Q; which of the folowing variables directly contributes to preload
venous return
Q; which of the following would NOT increase end diastolic volume
dehydration
Q; increased contractility of the heart results in all but which of the following
increased end systolic volume
Q; which of the does not affect stroke volume
all fo these affect stroke volume: preload, contractility, afterload
Q: which of the following is not equivalent to the others
end distolic volume
define aortic valve stenosis
a condition where there is a partial blockage of the aortic semilunar valve, increasing reisstance to blood flow and left ventricular afterload
the increase contractility, the ________becomes thicker
myocardium
valves in the heart ensure that blood flows in
one direciton through the heart
Q: which of the following could cause an increase in peripheral resistance in the blood vessel
atherosclersis
Q; which structures in the heart ensure that one-way flow occures
valves
Q: whcih of the following might be seen in both the diseased heart and the athlete’s heart
thicker myocardium
Q: the type of resistance increased in aortic valve stenosis is
increased left ventricular afterload
