Cardiovascular System - Lecture 2

Question 1

What kind of circulation is insect circulation?

Answer 1

open circulation

Question 2

What is the circulatory fluid called in insects?

Answer 2

hemolymph

Question 3

What corresponds to the blood and interstitial fluid in vertebrates?

Answer 3

hemolymph

Question 4

Why doesn’t the circulatory system of insects not transport oxygen unlike the circulatory system of vertebrates?

Answer 4

because it does not have hemoglobin (respiration is carried out by the tracheal system)

Question 5

How does circulation move in insects?

Answer 5

from back to front due to the dorsal vessel made up of an aorta and thoracic bulbs (heart)

Question 6

What is the heart part of insects made up of?

Answer 6

chambers all ending in a valve called ostiole

Question 7

Where is the hemolymph pumped in insects?

Answer 7

ostiole

Question 8

What kind of circulation do fish have?

Answer 8

closed, single-loop

Question 9

How many heart chambers do fish have?

Answer 9

2

Question 10

Where does blood arrive in fish?

Answer 10

through the veins into the atrium then into the ventricle

Question 11

What allows the blood to be sent into the artery when it contracts in fish?

Answer 11

the ventricle

Question 12

At what level is blood deoxygenated in fish?

Answer 12

the gill branches

Question 13

What kind of circulation do amphibians and most reptilians have?

Answer 13

closed, double-loop circulation

Question 14

How many chambers of the heart do amphibians and most reptiles have?

Answer 14

3

Question 15

What are the 2 circulations called in amphibians and most reptilians?

Answer 15

• the small circulation or pulmonocutaneous circuit
• the large circulation or systemic circuit

Question 16

How are the chambers of the heart divided in amphibians and most reptilians?

Answer 16

2 atria and a single ventricle

Question 17

Where does the small circulation go towards after leaving the ventricle in amphibians and most reptilians?

Answer 17

the lungs and the skin (places where gas exchange takes place)

Question 18

How is blood ejected into the systemic circulation in amphibians and most reptilians?

Answer 18

blood enriched in O2 returns to the left atrium then passes into the ventricle

Question 19

Where does oxygen-depleted blood go in amphibians and most reptilians?

Answer 19

the right atrium then to the ventricle

Question 20

How many chambers does a crocodile’s heart have?

Answer 20

4

Question 21

How many aortas do crocodiles have?

Answer 21

2

Question 22

What does the right aorta connect in crocodiles?

Answer 22

the left ventricle to the systemic circulation

Question 23

What does the left aorta connect in crocodiles?

Answer 23

the right ventricle to the systemic circulation

Question 24

What is the valve between the right ventricle and the pulmonary circulation called in crocodiles?

Answer 24

“gear-tooth valve”

Question 25

What happens to the gear-tooth valve of crocodiles underwater?

Answer 25

it closes

Question 26

What happens to the oxygen-poor blood from the right side of the heart in crocodiles when the gear-tooth valve closes?

Answer 26

it enters the left aorta (systemic circulation)

Question 27

How many chambers does the mammalian heart have?

Answer 27

4

Question 28

What kind of circulation is the right heart responsible for in mammalians?

Answer 28

pulmonary circulation

Question 29

What kind of circulation is the left heart responsible for in mammalians?

Answer 29

systemic circulation

Question 30

What kind of circulation is the mammalian heart?

Answer 30

closed, double-loop

Question 31

Why is oxygenated blood separated from deoxygenated blood in mammalians?

Answer 31

to have a better supply of O2 to cells and tissues

Question 32

What is blood volume equal to?

Answer 32

5L (75 mL/kg)

Question 33

What is one unit of blood equal to?

Answer 33

450 mL

Question 34

What is stroke volume equal to?

Answer 34

70 mL

Question 35

What is the formula for stroke volume?

Answer 35

end-diastolic volume - end-systolic volume

Question 36

What % of blood is the venous system?

Answer 36

61%

Question 37

Why is the venous system compliant?

Answer 37

because it can change accordingly to the changes in volume

Question 38

What % of blood is the arterial system?

Answer 38

18%

Question 39

Why is the arterial system resistant?

Answer 39

because changes in volume increase resistance

Question 40

What is venous return?

Answer 40

the flow of blood from the periphery back to the atrium, and it is equal to cardiac output

Question 41

What is cardiac output?

Answer 41

the amount of blood the heart pumps in one minute and is equal to the heart rate multiplied by the stroke volume

Question 42

What would be the stroke volume if the cardiac output is 5L/min and the HR is 70 bpm?

Answer 42

70 mL

Question 43

What is blood flow?

Answer 43

the volume (V) of blood circulating per unit of time (T)

Question 44

How can blood flow be expressed?

Answer 44

mL/min or L/min

Question 45

What is the normalized blood flow?

Answer 45

mL/min/100 gm

Question 46

Why do we have a lot of capillaries?

Answer 46

to slow things down

Question 47

Why is flow = area x MEAN velocity?

Answer 47

because the velocity is not necessarily the same at every point in the cross section

Question 48

What is the structural difference bewteen arteries and veins?

Answer 48

veins have a valve

Question 49

What are the 4 advantages of branching networks?

Answer 49

✓ Cells are close to a capillary ✓ High total area of the wall of the capillaries ✓ Low blood flow velocity in the capillaries ✓ High total cross-sectional area