CARDIOVASCULAR SYSTEM

Question 1

ROLE OF A VALVE

Answer 1

Prevent backflow of blood and keep in one direction

Question 2

VENA CAVA

Answer 2

Brings in deoxygenated blood

Question 3

HEART HAS THREE LAYERS:

Answer 3

1) Epicardium
2) Myocardium
3) Endocardium

Question 4

THREE MAIN TYPES OF MUSCLE:

Answer 4

1) Skeletal muscle
2) Cardiac muscle
3) Smooth muscle

Question 5

MAXIMAL EXERCISE IS …

Answer 5

Physical activity performed at the highest intensity level a individual can achieve. It pushes the body to its absolute limit.
Intensity- near 100% of an individuals HR
Duration- typically short in duration
Benefits- enhances maximum strength, speed and power

Question 6

SUBMAXIMAL EXERCISE IS …

Answer 6

Physical activity performed at an intensity level that is below the maximum capacity of an individual. It doesn’t push the body to its utmost limit.
Intensity- typically, less than 70-85%
Duration- sustained for longer periods of time as its not demanding
Benefits- improves cadiovascular health, endurance

Question 7

CARDIO VASCULAR SYSTEM COMPOSED OF THREE MAIN PARTS:

Answer 7

1) The heart
2) The blood vessels
3) The blood

Question 8

CARDIOVASCULAR SYSTEMS FUNCTION IS…

Answer 8

To deliver oxygen and nutrients and excrete waste products from all cells of the body - as well as regulating body temperature (thermoregulation)

Question 9

DOUBLE PUMP CIRCUIT :
- PULMONARY CIRCUIT
- SYSTEMIC CIRCUIT

Answer 9

PC- Carries deoxygenated blood to the lungs and oxygenated blood back to the heart

SC- Carries oxygenated blood to the body tissues and deoxygenated blood back to the heart.

Question 10

SA NODE

Answer 10

This is the hearts natural pacemaker, it sends an electrical signal that tells the heart to beat. This signal starts in the upper right part of the heart (right atrium). This causes the filling of the two atriums.

Question 11

AV NODE (ATRIOVENTRICULAR NODE)

Answer 11

After the signal from the SA node causes the atria (upper chambers) to contract, the AV node slows the signal down slightly before sending it to the ventricles (lower chambers). This delay allows the atria to empty fully before the ventricles contract.

Question 12

BUNDLE OF HIS

Answer 12

The electrical signal travels from the AV node to the bundle of His, which splits into two branches, one for each ventricle.

Question 13

PURKINJE FIBERS

Answer 13

These fibers spread the electrical signal through the ventricles, causing them to contract and pump blood out of the heart.

Question 14

MYOGENIC

Answer 14

The heart can make its own heart beat.

Question 15

SYSTOLE

Answer 15

Contraction of the heart

Question 16

DIASTOLE

Answer 16

Relaxation of heart

Question 17

HEART RATE

Answer 17

The number of times the heart beats, per minute (bpm)
Average resting heart rate
Males= 70bpm
Females= 72bpm

Question 18

BRADYCARDIA

Answer 18

A decrease in resting heart rate to below 60bpm

Question 19

STROKE VOLUME

Answer 19

The amount/ volume of blood pumped out of the left ventricle, per beat/ contraction.

Question 20

HOW IS STROKE VOLUME DETERMINED

Answer 20

• Determined by venous return

Question 21

VENOUS RETURN

Answer 21

The volume of blood returning to the heart via the veins

Question 22

FRANK STARLING’S LAW

Answer 22

The elasticity of the cardiac fibers - concerned with the degree of stretch during the diastole phase. Greater cardiac fibers stretch - greater contraction - greater SV
greater stretch = greater contraction force

Question 23

EJECTION FRACTION

Answer 23

The percentage % of blood pumped out of the left ventricle, per beat.

EJ = SV / EDV X 100

Question 24

POCKET VALVES

Answer 24

If there is a sufficient pressure the blood will sit in the pocket valves of the veins. Prevent backflow - pooling.

Question 25

MUSCLE PUMP

Answer 25

Veins situated between skeletal muscles which help squeeze blood back to the heart when they contract and relax

Question 26

RESPIRATORY PUMP

Answer 26

Aids blood flow through the veins of the thorax and abdomen. Breathing deeper increases pressure in the thorax and abdomen

Question 27

SMOOTH MUSCLE

Answer 27

Thin layer of smooth muscle helps squeeze blood back towards the heart

Question 28

GRAVITY

Answer 28

An ever-present force against which the limbs venous system is designed to compete in the upright position. Blood from upper body id aided in its return by gravity.

Question 29

VASODILATION

Answer 29

Vessels expanding

Question 30

VASOCONSTRICTION

Answer 30

Vessels constricting

Question 31

PART OF HEART THAT UNDERGOES HYPERTROPHY

Answer 31

Myocardium

Question 32

CARDIAC OUTPUT (Q)

Answer 32

The amount/ volume of blood pumped out by the left ventricle, per minute HR X SV = Q If HR or SV increases, then cardiac output increases also.

Question 33

RESPONSE TO EXERCISE: CHANGES IN HEART RATE

Answer 33

-Heart rate increases with exercise - But how much it increases depends on the intensity of the exercise - Heart rate increases in direct proportion to exercise intensity - The greater the exercise intensity, the greater the heart rate.

Question 34

RESPONSE TO EXERCISE: STROKE VOLUME

Answer 34

- SV increases as exercise increases - But only increases up to 40-60% of maximum effort/ intensity - After this point, SV starts to level out/ drop slightly.

Question 35

RESPONSE TO EXERCISE: CARDIAC OUTPUT

Answer 35

- Q increases during exercise - The heart (myocardium) gets physically bigger and stronger (hypertrophy) - A bigger heart means more blood can be pumped out by the left ventricle, per beat SV, however due to this RHR will decrease - So at rest, increased SV X decreased HR = Q remaining unchanged - But, during exercise HR increases SV - So during exercise, increased SV X increased HR = INCREASED Q