Chapter 14 - Guyton

Question 1

Blood flows at a rate of:

Answer 1

5 L/min

Question 2

Transports blood to tissue under high pressure 100 mmHg.

Answer 2

aorta and arteries

Question 3

Control site for blood flow and major resistance site for circulation.

Answer 3

arterioles

Question 4

Major site of water and solute exchange between blood and tissues.

Answer 4

capillaries

Question 5

Returns blood to the heart under low pressure, serves as reservoir for blood.

Answer 5

superior and inferior vena cava, veins, venules, venous sinuses

Question 6

Site of oxygen and carbon dioxide exchange.

Answer 6

pulmonary circulation

Question 7

What has the largest total cross-sectional area of the circulation?

Answer 7

capillaries (1000x aorta)

Question 8

Velocity of blood flow from greatest to least.

Answer 8

Aorta>arterioles>capillaries>small veins

Question 9

The majority of blood volume at any given time is located where?

Answer 9

in the veins

Question 10

Where is the largest pressure drop in circulation?

Answer 10

arteriole-capillary junction

Question 11

Cardiac output is mainly controlled by:

Answer 11

local tissue flow

Question 12

Does local blood flow or cardiac output control arterial pressure?

Answer 12

no (nervous system and then renal for long term)

Question 13

Flow (Q) through a blood vessel is determined by:

Answer 13

the pressure difference (P1-P2) between the two ends of a vessel and resistance (R) of the vessel

Question 14

What is laminar flow?

Answer 14

velocity of blood in the center of the vessel is greater than toward the outer edge creating a parabolic profile (silent)

Question 15

What are some causes of turbulent flow?

Answer 15

high velocities, sharp turns in circulation, rough surfaces in the circulation, rapid narrowing of blood vessels (makes murmurs)

Question 16

What is conductance?

Answer 16

measure of blood flow through a vessel for a given pressure difference, increases in proportion to the fourth power of the diameter (more sensitive to change in diameter of a vessel)

Question 17

Poiseuille’s law

Answer 17

integrating the velocities of all the concentric rings of flowing blood and multiplying them by the areas of the rings (laminar flow)

Question 18

Would a single upper extremity amputee have higher, lower, or normal blood pressure?

Answer 18

Amputation of a limb or surgical removal of a kidney also removes a parallel circuit and reduces the total vascular conductance and total blood flow (i.e., cardiac output) while increasing total peripheral vascular resistance. (higher than normal blood pressure)

Question 19

polycythemia

Answer 19

hematocrit >55; increased red blood cells or decreased plasma. blood flow is retarded.