Vasodilation of arterioles in the skeletal and heart muscles and skin
causes a decrease in total peripheral resistance to blood flow. This decrease is partially offset by vasoconstriction of arterioles in other organs.
Which of the following will decrease total peripheral resistance to blood flow?
Hematocrit measures the proportion of the the blood made up of the RBCs (Red blood cells). RBC’s carry oxygen from lungs to different tissues of the body.
Lowering of red blood cells
results in the reduction of blood viscosity causing the decrease in the peripheral resistance to blood flow.
Which of the following would decrease total peripheral resistance to blood flow decreasing the hematocrit?
Vasodilation of arterioles in the skeletal and heart muscles and skin
causes a decrease in total peripheral resistance to blood flow. This decrease is partially offset by vasoconstriction of arterioles in other organs.
Which of the following will decrease resistance to blood flow?
In the arterial system, vasodilation and vasoconstriction of the arterioles is a significant factor in systemic blood pressure:
Slight vasodilation
greatly decreases resistance and increases flow, whereas slight vasoconstriction greatly increases resistance and decreases flow.
What happens when peripheral resistance decreases?
In conditions such as shock, there is a decrease in vascular resistance thus causing
decreased organ perfusion
which leads to organ malfunction.
Which of the following is the most significant source of blood flow resistance?
The correct answer is option (c)
blood viscosity
. Blood viscosity is the most significant source of blood flow resistance.
Which of the following will cause an increase in peripheral resistance?
Peripheral resistance is determined by three factors: Autonomic activity: sympathetic activity constricts peripheral arteries. Pharmacologic agents: vasoconstrictor drugs increase resistance while vasodilator drugs decrease it.
Blood viscosity
: increased viscosity increases resistance.
How does resistance affect blood flow?
Resistance is a force that opposes the flow of a fluid. In blood vessels, most of the resistance is
due to vessel diameter
. As vessel diameter decreases, the resistance increases and blood flow decreases. Very little pressure remains by the time blood leaves the capillaries and enters the venules.
Why would an increase in total peripheral resistance increase the blood pressure?
Total peripheral resistance
We increased
the pressure by decreasing the space the flow of water could go through
. The same principle applies in the body with blood and the vessels. In cardiovascular terms this is known as ‘total peripheral resistance’ (TPR).
How does TPR affect diastolic pressure?
TPR is responsible
for maintaining the diastolic blood pressure
. The major contribution to the TPR is provided by the systemic arterioles. By the time the blood reaches the systemic arterioles, its pressure has dropped to 50 mm of Hg in overcoming the vascular resistance encountered up till now.
Which of the following has the greatest effect on blood flow?
Which of the following has the greatest effect on blood flow? You correctly answered:
blood vessel radius
.
How does blood viscosity affect blood flow?
Increased viscosity increases the resistance to blood flow
and thereby increases the work of the heart and impairs organ perfusion. Some patients with anemia have low hematocrits, and therefore reduced blood viscosities. Another important factor that influences blood viscosity is temperature.
What are the 5 factors that affect blood pressure?
- Cardiac output.
- Peripheral vascular resistance.
- Volume of circulating blood.
- Viscosity of blood.
- Elasticity of vessels walls.
What has the greatest effect on peripheral resistance?
The last factor affecting resistance is
blood vessel diameter
. This factor is the most variable of the three and has the greatest impact on resistance. … So the peripheral blood vessels dilate to increase blood flow to the limbs.
What is the most significant factor affecting peripheral resistance?
The three most important factors affecting resistance are
blood viscosity, vessel length and vessel diameter
and are each considered below.
What causes low vascular resistance?
Although many clinical conditions can cause a low SVR,
septic shock
remains the most common cause and usually results in a severe decrease in SVR. In more than 90% of patients with septic shock who are aggressively volume loaded, the CO is initially normal or elevated.
