Chapter 14

Question 1

2) What are the major differences between the atria and ventricles?

Answer 1

2) The atria stand for the upper chambers of the heart, while the ventricles are the lower chambers. 2. Atria act as receptors of deoxygenated blood, while ventricles receive blood from the left atria and force it into the aorta.

Question 2

4) The cardiac circuit that delivers blood to and from the lungs is called the;

Answer 2

4) Pulmonary circuit.

Question 3

5) The cardiac circuit that delivers blood to and from the body is called the;

Answer 3

5) Systemic circuit.

Question 4

6) Why is the human circulatory system called “closed”?

Answer 4

6) This means that blood is always enclosed in vessels.

Question 5

7) Blood that is moving away from the heart would be found in;

Answer 5

7) Arteries.

Question 6

8) Red blood is found in;

Answer 6

8) All blood vessels.

Question 7

9) Gas and nutrient exchange always takes place in the;

Answer 7

9) Capillaries.

Question 8

10) Blood that is moving away from the heart would be found in;

Answer 8

10) Arteries.

Question 9

11) Blood always flows down a ___ gradient

Answer 9

11) Pressure.

Question 10

12) Which blood vessel has the highest blood pressure? The lowest?

Answer 10

12) Highest at the heart (aorta) Lowest at vena cava.

Question 11

13) What percent of the initial pressure is lost as blood moves through the circulatory system?

Answer 11

13) 90%.

Question 12

14) In what units is blood flow rate measured in?

Answer 12

14) L/min.

Question 13

15) What is the equation that determines flow velocity?

Answer 13

15) v= rate/cross-sectional area of vessel.

Question 14

16) What 3 forms of resistance slow blood flow?

Answer 14

16) Vessel diameter; smaller= decrease flow
Blood viscocity; thicker= decreased flow
Tube length; longer = decreased

Question 15

17) The membranous sac that covers and protects the heart is called the;

Answer 15

17) Pericardium.

Question 16

18) What vessels supply the heart with nutrients and oxygen?

Answer 16

18) Coronary vessels.

Question 17

19) What type of valves would you find between; atria and ventricles? Ventricles and arteries?

Answer 17

19) The atria and the ventricles are separated by valves called atrioventricular valves. The valve between the right atrium and right ventricle is called the tricuspid valve. The left atrium and left ventricle are separated by the mitral valve.

Question 18

20) How are AV valves different from semilunar valves in structure?

Answer 18

20) Atrioventricular valves are much better at restricting flow, they have chordates tendineae and papillary muscles to reinforce the muscles. Semilunar valves don’t have ability to withstand back flow.

Question 19

21) What term refers to the muscle tissue that makes up the majority of the structure of the heart:

Answer 19

21) Myocardium.

Question 20

22) What term means that a tissue can generate action potentials without a stimulus?

Answer 20

22) Autorythmic.

Question 21

23) What are the major function(s) of the desmosomes in the heart tissue?

Answer 21

23) Cell to cell connections, transfer force.

Question 22

24) What are the major function(s) of the gap junctions in the heart tissue?

Answer 22

24) Fast electrical signal transfer.

Question 23

25) Why do heart muscle cells have so many mitochondria? Such large T-tubules?

Answer 23

25) The heart is constantly working. Mitochondria provide energy to all the cells in the body. The cells in the heart are working all the time and working hard. As a result the cells need a lot of energy and therefore a lot of mitochondria to produce the energy. Large T-tubules are for spread into from surface to center.

Question 24

26) As heart muscle is stretched, the force it can generate goes down T/F

Answer 24

26) F.

Question 25

27) How is the job of the SA node different from that of the AV node?

Answer 25

27) SA node: Set the pace of the heartbeat at 70 bpm and begins heart contraction cycle.
AV node: 50 bpm and purkinje fibers 25-40 bpm, can act as pacemakers.Slow heart rate.

Question 26

30) The division of the autonomic nervous system that causes an increase in heart rate is the;

Answer 26

30) Sympathetic division.

Question 27

31) The division of the autonomic nervous system that causes a decrease in heart rate is the;

Answer 27

31) Parasympathetic division.

Question 28

32) What structure generates action potentials for the heart?

Answer 28

32) Sinoatrial node (SA).

Question 29

34) What two nervous structures in the heart help to both spread the action potential and create a pause in the cycle?

Answer 29

34) SA and AV nodes.

Question 30

35) Where does a ventricular contraction begin (what part of the heart?) Why?

Answer 30

35) Apex of the heart (Bottom) to squeeze upward like toothpaste.

Question 31

37) What term means that the heart chambers relax, filling with blood?

Answer 31

37) Late diastole.

Question 32

38) What term means that the heart chambers contract, forcing blood out?

Answer 32

38) Ventricular ejection.

Question 33

39) What do EDV and ESV stand for? What can they be used to calculate?

Answer 33

39) End diastolic volume and end systolic volume. Stroke volume.