Chapter 14 general questions

Question 1

Cardiovascular system: moves blood from veins to arteries (blood vessels that carry oxygen-poor blood to your heart)

Answer 1

• closed-loop
• The right side pumps blood to the lungs
• The left pumps blood everywhere else
• The right heart is fairly low-pressure bc it doesn’t have to go very far to go through the lungs & too much pressure will cause problems in the lungs
• The left heart produces a lot of pressure bc it has to push blood all the way through body

Question 2

What is the difference between deoxygenated and oxygenated blood?

Answer 2

The blood that has a higher concentration of oxygen is known as oxygenated blood.

The blood that has a higher concentration of carbon dioxide is known as deoxygenated blood.

The deoxygenated blood flows through the veins.

The oxygenated blood flows away from the heart.

Question 3

Why is vasoconstriction / dilation such a big deal?

Answer 3

can change the flow a lot by contracting smooth muscle and altering the radius of the blood vessel

Question 4

Trip 1:

Answer 4

Lungs right heart

Question 5

Pressure gradient in systemic circulation

Answer 5

the heart is a pump which will generate pressure

• the first big artery coming out of the heart is the aorta which branches into the artery that carries blood to the kidney.
• the exchange happens in capillarities, delivering oxygen to the tissues & taking waste products and CO2 away.
• vena cavae brings blood back to the heart

Question 6

flow will happen in:

Answer 6

-flow will happen from higher pressure to an area of lower pressure

• low pressure in veins

Question 7

Fluid requires a pressure gradient

Answer 7

higher pressure —— flow —-> lower pressure

how much flow? 100 mmHg to 100 mmHg? None there’s no pressure difference so blood will just sit there.

Question 8

Flow and pressure gradient

Answer 8

flow:
100 mm Hg ——> 75 mm Hg

40 mm Hg ——–> 15 mm Hg

The highest flow: flow is equal to 25 mm Hg difference. Depends on the change in pressure

The bigger the pressure difference, the stronger the flow

big hose and small –> more flow in a big hose compared to small hose

Question 9

The bigger the resistance the less ______ you have

Answer 9

flow

• a little hose has a higher resistance than a big hose you will have more flow going through a big small than a small hose.

r is raised to 4, any change you make in the radius is going to be raised to the 4th power

flow is 16 times higher if you double the diameter of the tube

Question 10

Two kinds of myocardial cells

Answer 10

contractile cells (generate power stroke of the heart). contract when told to

autorhythmic cells: generate rhythm

Question 11

SA node:

Answer 11

main pacemaker of the heart and it will generate rhythmic action potential and set the pace

Question 12

contractile cells

Answer 12

think about how they are different from skeletal:
smaller, in the skeletal muscle all of those muscle cells are assembled into one cell. They fuse and muscle cell goes all the way from one tendon to another tendon.

Cardiac contractile cells are smaller and have a single nucleus and they tend to branch. Instead of being fused like skeletal muscle fibers to make one big cell they keep their identity but are connected by intercalated disks (hold the cells together, they have gap junction so electrical activity can pass from one cell to the next).

They hold together bc they have desmosomes when they contract they stay together.

Question 13

Both have

Answer 13

both striated
t-tubules are larger and branch
sarcoplasmic reticulum is smaller

Question 14

Cardiac muscle (excitation-contraction coupling and relaxation in cardiac muscle)

Answer 14

1. you get an AP in the membrane —> opens voltage-gated ca+ channels
   2

Question 15

Trip 2:

Answer 15

Systemic left heart

Question 16

what does veins and arteries do to the heart?

Answer 16

Veins bring blood to your heart.

Arteries take blood away from your heart.

Question 17

Which of the following would increase cardiac output to the greatest extent?

Answer 17

increased heart rate and increased stroke volume.
* cardiac output = heart rate x stroke volume.

Question 18

Which of the following would increase heart rate?

Answer 18

epinephrine (Adrenaline makes your heart beat faster and your lungs breathe more efficiently. It causes the blood vessels to send more blood to the brain and muscles, increases your blood pressure, makes your brain more alert, and raises sugar levels in the blood to give you energy. Your pupils grow larger and you sweat.)

norepinephrine (norepinephrine increases heart rate and blood pumping from the heart)

both play a role in your body’s natural fight-flight response to stress

Question 19

How would an increase in the sympathetic nervous system increase stroke volume?

Answer 19

increased contractility.

• by increasing available calcium), thus increasing stroke volume. Contractility causes an increase in stroke volume by decreasing end systolic volume; it does not change end diastolic volume.

Question 20

By what mechanism would an increase in venous return increase stroke volume?

Answer 20

increased end diastolic volume.

• an increase in venous return increases the end diastolic volume. The fibers are stretched more, resulting in an increase in the force of contraction (preload, or the Frank-Starling Mechanism).

Question 21

How would a decrease in blood volume affect both stroke volume and cardiac output?

Answer 21

decreased stroke volume and no change in cardiac output.

• ecreased blood volume would decrease the end diastolic volume, thus lowering the stroke volume. Although this would initially lead to a decrease in the cardiac output, heart rate would increase because of increased activity of the sympathetic nervous system in an effort to maintain cardiac output.

Question 22

Which of these is the best definition of an artery?

Answer 22

A vessel that carries blood away from the heart

Question 23

Most of the oxygen exiting the blood and entering the tissues does so from the ________.

Answer 23

capillaries

Question 24

Arteries are most accurately defined as blood vessels that ________.

Answer 24

carry blood away from the heart

Question 25

Which blood vessels return blood to the heart?

Answer 25

veins

Question 26

Consider three blood vessel segments of equivalent length and diameter: vessels A, B, and C.
Pressure at the beginning of each segment is as follows:
A) P = 100 mmHg;
B) P = 80 mmHg;
C) P = 60 mmHg.
Pressure at the end of each segment is as follows:
A) P = 70 mmHg;
B) P = 50 mmHg;
C) P = 30 mmHg.
Which vessel has the greatest blood flow through the described segment?

Answer 26

Flow rate is the same in all three segments.
All three vessels have the same resistance and the pressure gradient is the same in all three segments: A) ΔP = 100 - 70 = 30 mmHg; B) ΔP = 80 - 50 = 30 mmHg; C) ΔP = 60 - 30 = 30 mmHg.

Question 27

Which of these would cause an increase in blood flow through a vessel?

Answer 27

Vasodilation

Question 28

What is an advantage to the longer duration of cardiac action potential compared to the skeletal muscle action potential?

Answer 28

The longer duration prevents tetanic contraction, which ensures that the heart chambers will relax and refill with blood before the next contraction.

Question 29

What is the role of heart valves?

Answer 29

Heart valves ensure one-way flow of blood through the heart chambers.

Question 30

Which cells act as the heart’s pacemaker? Why are they the pacemaker cells?

Answer 30

Cells of the SA node are the usual pacemaker, because they are autorhythmic cells and set the pace of the heart rate.

Question 31

In skeletal muscle cells, action potentials cause the release of calcium from the SR by directly opening SR voltage-gated calcium channels. What causes the release of calcium from the SR in cardiac muscle cells?

Answer 31

Influx of extracellular calcium ions opens ryanodine receptors allowing Ca2+ to flow out of the SR.

Question 32

Calcium ions are removed from the sarcoplasm of the cardiac cell by the action of the sarcoplasmic reticulum (SR) Ca2+-ATPase pump and which other mechanism?

Answer 32

sodium-calcium exchanger on the sarcolemma

Question 33

The autorhythmicity of cardiac pacemaker cells is made possible by the reduced permeability of _______.

Answer 33

potassium

Question 34

The repolarization of cardiac muscle is due to _______

Answer 34

potassium exiting the cell

Question 35

The total refractory period of cardiac muscle _______.

Answer 35

is longer than the total refractory period for skeletal muscle

Question 36

When the cardiac muscle cell is at rest, the concentration of _____________ is greater on the outside of the cell.
sodium and calcium

Answer 36

sodium and calcium

Question 37

The movement of _______________ into the cardiac muscle cell depolarizes the cardiac muscle cell.

Answer 37

sodium and calcium

Question 38

ECG

Answer 38

Electrocardiogram to measure the electrical activity of the heat

Question 39

When does the heart’s pacemaker begin?

Answer 39

The SA node (generates an electrical signal that causes the upper heart chambers (atria) to contract) depolarizes and the electrical signal rushes through the atria down the interventricular septum to the apex and up the ventricle of the wall. The signal causes the muscle cells along the way to contract.

Question 40

Waves

Answer 40

P-wave which represents atrial depolarization
QRS wave complex - combines ventricular depolarization and atrial repolarization.
T-wave - ventricular repolarization

Question 41

Einthoven’s triangle

Answer 41

• A lead consists of two electrodes, one positive and one negative