Nordgren: CV Overview

Question 1

What is the role of the cardiovascular system in homeostasis?

Answer 1

To maintain homeostasis in the interstitial fluid

Question 2

What are the major fluid compartments and the approximate volumes for each?

Answer 2

ICF- w/in cells
30L (40% of body weight)

ECF outside cells
Interstitial= 12 L (80% of ECF)
Plasma=3L (20% of ECF)

Question 3

What are the two types of ECF?

Answer 3

interstitial- between cells, source of nutrients and waste deposit

plasma- fluid portion of blood and lymph

Question 4

What is the relationship between blood flow, blood pressure and vascular resistance?

Answer 4

Flow = pressure difference /resistance

Question 5

What is the average CO?

Answer 5

5-6 L/min

Question 6

What are physical factors that affect resistance?

Answer 6

length of tube
radius
viscosity

Question 7

What is the equation that relates resistance to flow?

Answer 7

poiseuille equation

flow= change in pressure x radius/
Length and viscosity

Question 8

What happens to flow as radius increases? As length and viscosity increases?

Answer 8

increase in radius > increase in flow

increase in length/viscosity> decrease in flow

Question 9

When does flow occur?

Answer 9

When there is a change in pressure difference (direction is from high to low P)

Question 10

What is the primary job of the heart?

Answer 10

maintain pressure gradient

Question 11

What surrounds the heart?

Answer 11

pericardium

Question 12

What side of the heart is oxygenated?

Answer 12

LEFT

Question 13

Describe the path of blood through the heart.

Answer 13

non-oxygenated blood from body>
RA>
RV>
lungs> gets oxygenated>
LA>
LV>
The body

Question 14

How does blood flow get to heart tissue?

Answer 14

via coronary arteries

carry oxygen and nutrients required for normal functioning of cardiac muscle

Question 15

What are the three main coronary arteries?

Answer 15

right coronary artery
Circumflex coronary artery
Left main coronary artery

Question 16

How does blood pass from the aorta to the coronary arteries?

Answer 16

through little openings (coronary ostia) in the cusps of aortic valves

Question 17

Why are valves present in the heart?

Answer 17

To dictate one way flow of blood

Question 18

What reduces the possibility of valve eversion?

Answer 18

chordae tendinae and papillary muscles connect to atrio-ventricular valves

Question 19

The RIGHT atrio-ventricular valve is the….

Answer 19

TRICUSPID

RST

Question 20

The LEFT atrio-ventricular valve is the…

Answer 20

BICUSPID/MITRAL

Question 21

What valves are located between the ventricles and the arteries?

Answer 21

Semilunar valves- each has 3 cup like leaflets

Pulmonary and aortic vlaves

Question 22

What is systole?

Answer 22

ventricular contraction

Question 23

What is diastole?

Answer 23

ventricular relaxation

Question 24

What is stroke volume?

Answer 24

Volume of blood ejected per beat

EDV (heart relaxed) - ESV (heart contracted)

Question 25

What is HR?

Answer 25

number of beats per minute

Question 26

What is CO?

Answer 26

Volume/min pumped out of the heart SV (volume/beat) x HR (beat/min)

Question 27

What initiates heart contractions?

Answer 27

electrical stimulus

Question 28

What leads to automacticity in the heart?

Answer 28

pacemaker cells have an unstable membrane potential

Question 29

What is the path of electrical conduction in the heart?

Answer 29

``` SA node > atrial tissues> internodal tracts> AV node> bundle of his> purkinje fibers> ventricles ```

Question 30

What allows for the spread of electrical conduction?

Answer 30

gap junctions

Question 31

What is required to pass the impulse to the ventricle?

Answer 31

AV node

Question 32

Where is the sinoatrial node located?

Answer 32

RA

Question 33

Where are the internodal tracts?

Answer 33

between the SA node and the AV node

Question 34

Where is the atrioventricular node located?

Answer 34

Between the atria and ventricles of the heart. Connects the two

Question 35

Where is bachmans bundle located?

Answer 35

in the LA

Question 36

Where are the purkinje fibers locate?

Answer 36

in the apex of the heart

Question 37

What does the parasympathetic NS do?

Answer 37

Decrease HR (SA node) Decrease AP conduction velocity (AV node) Decrease force of contraction

Question 38

What does the sympathetic nervous system do?

Answer 38

increase HR increase AP conduction velocity Increase force of contraction increase rate of contraction/relaxation

Question 39

What is Starlings law of the heart?

Answer 39

The heart pumps what it receives! If cardiac filling increases during diastole the volume ejected during systole also increases.

Question 40

What most strongly influences SV/CO?

Answer 40

cardiac filling during diastole

Question 41

What are the 5 basic requirements for effective ventricular pumping?

Answer 41

1. Contractions of individual cardiac muscle cells must be at REGULAR intervals and SYNCRHONIZED 2. Valves must open fully 3. valves must not leak 4. Muscle contractions must be forceful 5. Ventricles must fill adequately during diastole

Question 42

What causes arrythmia?

Answer 42

When contraction of individual muscle cells aren't synchronized

Question 43

What is stenosis?

Answer 43

When valves don't open fully

Question 44

What does it mean if a valve is regurgitant?

Answer 44

it leaks

Question 45

What does it mean if a heart is failing?

Answer 45

Muscle contractions aren't forceful enough

Question 46

What are the major roles of arteries?

Answer 46

Pressure reservoir | divergent flow

Question 47

What is the role of capillaries?

Answer 47

Site of diffusion

Question 48

What is the main role of veins?

Answer 48

Volume reservoir | Convergent flow

Question 49

What causes constriction of arterioles, venules and veins?

Answer 49

Sympathetic nerve activity> reduction in diameter and decreased blood flow

Question 50

How do metabolic changes affect arteriolar smooth muscle?

Answer 50

Increased tissue metabolic rate> arteriolar dilation> increased tissue blood flow

Question 51

What is the basic composition of the fluid and cellular portions of blood?

Answer 51

Blood cells- 40% blood volume red- Oxygen white- immunity platelet- clotting Plasma- liquid blood ocmponent electrolytes proteins

Question 52

What regulates blood flow through individual organs?

Answer 52

changes in diameters of their arterioles

Question 53

What does blood do?

Answer 53

Suspension of red, white and platelets in plasma that carry gases, salts, nutrients and waste molecules.