3.5 -- Vasculature

Question 1

As the right heart pumps deoxygenated blood to the lungs, what does it drop off and what does it pick up?

Answer 1

Drops off CO2 and picks up O2

Question 2

Do lungs always get 100% of total cardiac output?

Answer 2

Yes

Question 3

What is the arrangement of capillary beds for each organ?

Answer 3

Parallel

Question 4

Veins function as a storage for blood, being a what?

Answer 4

Volume resevoir

Question 5

Progressively branching arteries lead to capillary beds for gas exchange, to drop off what and pick up what?

Answer 5

Drop off O2 and pick up CO2

Question 6

What path does the blood take starting with the aorta?

Answer 6

Aorta –> Other arteries –> Arterioles –> Capillaries

Question 7

What path does the blood take starting with venules?

Answer 7

Venules –> Veins –> Vena cava

Question 8

Valves in the what and what assure one-way flow?

Answer 8

Veins and hearts

Question 9

Each side of the heart functions as what?

Answer 9

An independent pump

Question 10

What maintains blood pressure/flow during ventricular relaxation?

Answer 10

Elastic systemic arteries

Question 11

What is the purpose of the capillaries?

Answer 11

Exchange between the blood and the cells

Question 12

What is the site of variable diameter/resistance?

Answer 12

Arterioles

Question 13

Large arteries, such as what, are pressure resevoirs?

Answer 13

Aorta

Question 14

What is closer to the heart and stretch as blood is pumped into them and recoil when ventricles relax?

Answer 14

Elastic arteries

Question 15

At the end of systole (ejection), what pressure is highest? What is the approximate systolic BP?

Answer 15

Aortic pressure, with approximately 120 mmHg for systolic BP

Question 16

At the end of IVC (just before the next ejection), what pressure is lowest? What is the approximate diastolic BP?

Answer 16

Aortic pressure, with approximately 80 mmHg for diastolic BP

Question 17

Do the arteries send blood forward into the rest of circulatory system during relaxation or contraction?

Answer 17

Relaxation

Question 18

Pressure waves created by ventricular what travel into the blood vessels?

Answer 18

Ventricular contraction

Question 19

Pressure in the arterial side of the circulation cycles but the what diminish in amplitude with distance and disappear at capillaries?

Answer 19

Pressure waves

Question 20

What is pulse pressure?

Answer 20

Systolic pressure minus diastolic pressure

Question 21

What is mean arterial pressure?

Answer 21

Diastolic pressure + 1/3rd of pulse pressure

Question 22

Contraction or relaxation of smooth muscles in arterioles (increase or decrease in diameter) regulates blood pressure and flow to what?

Answer 22

Capillary beds

Question 23

What is farther from the heart, has more smooth muscle in proportion to diameter, and also has more resistance due to smaller lumen?

Answer 23

Muscular arteries/arterioles

Question 24

What provides the greatest resistance to flow, sets blood pressure and controls blood flow to the capillaries via smooth muscle contraction?

Answer 24

Arterioles

Question 25

Are capillaries leaky vessels when it comes to exchange?

Answer 25

Yes

Question 26

Capillaries exchange nutrients and gases between blood and the what?

Answer 26

ISF/Cells

Question 27

What can close off capillaries in response to local signals, or cellular activity such as levels of CO2/O2 or pH?

Answer 27

Precapillary sphincters

Question 28

What two things regulate blood flow to capillaries?

Answer 28

Precapillary sphincters and vasoconstriction and vasodilation of arteriole smooth muscle

Question 29

At rest, approximately how much blood is in the veins?

Answer 29

2/3rds

Question 30

Veins are a volume resevoir but have low what?

Answer 30

Pressure

Question 31

What has thinner walls than arteries, larger lumen, more stretchy, and some smooth muscle?

Answer 31

Veins

Question 32

What ensures one-way directional flow to the heart?

Answer 32

Venous valves

Question 33

What help contract muscle surrounding veins to help force blood towards the heart, which is important during exercise?

Answer 33

Skeletal muscle pumps

Question 34

The contraction of smooth muscle in the veins constricts the veins, doing what to the diameter? This causes what space for the blood in the veins and sends more blood back to the heart? This increases what two things?

Answer 34

Decreases diameter, causing less space. Increases venous return and filling of ventricle

Question 35

What will increase venous return as well?

Answer 35

Sympathetic stimulation (Alpha1 receptor)

Question 36

Which vasculature is a pressure reservoir and has elastic walls to maintain pressure and flow when the ventricle is not ejecting?

Answer 36

Arteries

Question 37

Which vasculature regulates blood flow/pressure and has smooth muscle contraction?

Answer 37

Arterioles

Question 38

Which vasculature perfuses cells and has a single layer leaky wall?

Answer 38

Capillaries

Question 39

Which vasculature is a volume reservoir with one-way valves, smooth muscle contraction, and increases venous return?

Answer 39

Veins