Circulatory & Respiration

Question 0

Increase in venous return results in an increase in _____, which lengthens cardiac fibers, which improves the force of contractility, resulting in an increase in _____.

Answer 0

1. End-Diastolic BP

2. Stroke Volume

Question 1

End-Diastolic Volume

Answer 1

(Preload)

How much blood is in the left ventricle before it squeezes

Question 2

Factors of Venous Return

Answer 2

1. Venoconstriction
2. Muscle Pump
3. Respiratory Pump

Question 3

Venoconstriction

Answer 3

Reduces the volume capacity of the veins to store blood –> blood moves toward heart

Question 4

Muscle Pump

Answer 4

When muscles contract during exercise, they compress veins & push blood back toward the heart

Question 5

Respiratory Pump

Answer 5

During inspiration, pressure in the thorax decreases & the abdominal pressure increases. This creates a flow of venous blood from the abdominal region into the thorax = venous return

Predominant factor of venous return.

Question 6

Stroke Volume

Answer 6

Volume per beat

Question 7

Stroke Volume is regulated by?

Answer 7

1. End-Diastolic Volume
2. Afterload (Aortic BP)
3. Strength of ventricular contraction (Contractility)

Question 8

Preload

Answer 8

The pressure on the wall of the heart

**more blood = more pressure

Question 9

Afterload

Answer 9

The pressure on the aortic semilunar valve (Diastolic BP)

Overcoming the pressure to open the semilunar valves

Question 10

Stroke Volume in relation to Afterload

Answer 10

SV is inversely proportional to the Afterload; increase in aortic pressure produces a decrease in SV

Question 11

Contractility

Answer 11

How hard the heart squeezes

Question 12

Mechanisms of Contractility

Answer 12

• the effect of epinephrine & norepinephrine
• direct sympathetic stimulation by cardiac accelerator nerves

Both increase the Calcium available to the myocardial cell

Question 13

Ejection Fraction

Answer 13

The percentage of blood pumped out of a filled ventricle during contraction.

The greater the EF, the greater the Stroke Volume which increases Cardiac Output.

Question 14

Cardiac Output

Answer 14

Volume of blood pumped to the body per minute

Q= HR * SV

Question 15

Heart Rate

Answer 15

Beats per minute

Question 16

Isovolumic Contraction

Answer 16

The pressure increases while volume stays the same

Question 17

Surfactant

Answer 17

Lowers the surface tension of the alveoli & prevents its collapse

Question 18

Purpose of the Cardiovascular System

Answer 18

1. The transport of O2 to the tissues & removal of wastes
2. The transport of nutrients to tissues
3. Regulation of body temperature

Question 19

Myocardium

Answer 19

“Heart Muscle”

-responsible for contracting & forcing blood out of the heart

Question 20

Cardiac Muscle Fiber vs. Skeletal Muscle Fibers

Answer 20

1. They’re shorter & connected in a tight series; branched & contraction is involuntary
2. They’re interconnected via intercalated discs (permit the transmission of electrical impulses from one fiber to another)
3. Fibers cannot be divided into different fiber types (type similar to SO Type I)

Question 21

Systole

Answer 21

Contraction phase of the cardiac cycle

Question 22

Diastole

Answer 22

Relaxation period of the cardiac cycle

Question 23

Heart 2-Step Pumping Action

Answer 23

1. Right & Left Atria contract together, which then empties atrial blood into the ventricles.
2. Then ventricular contraction occurs, delivering blood into systemic & pulmonary circuits.

Question 24

Blood Distribution During Rest

Answer 24

Systole ejects 2/3s of the blood in the ventricles, leaving 1/3 in the ventricles. Ventricles then fill with blood during the next diastole (longer time in diastole)

Question 25

The effects of rising heart rate on Diastole & Systole

Answer 25

Rising heart rate results in a greater time in reductionism diastole, whereas systole is less affected. (Diastole is reduced greatly)

Question 26

Pressure Changes During the Cardiac Cycle

Answer 26

70% of the blood entering the atria during diastole flows directly into the ventricles through the atrioventricular valves before contraction. Contraction then forces the remaining 30% into the ventricles. The rise in pressure closes the AV Valve & prevents backflow.

Question 27

Pressure Changes During the Cardiac Cycle (continued...)

Answer 27

When the ventricular pressure exceeds the pressure of the pulmonary artery & the aorta, the pulmonary & aortic valves open & blood is forced into both pulmonary & systemic circulations.

Question 28

Heart Sounds

Answer 28

1st- closing of the AV valve | 2nd- closing of the aortic & pulmonary valves

Question 29

Systolic BP

Answer 29

Pressure generated as blood is ejected from the heart during ventricular systole

Question 30

Diastolic BP

Answer 30

Time during ventricular relaxation (diastole) & the arterial blood pressure decreases

Question 31

Mean Arterial Blood Pressure (MAP)

Answer 31

Average pressure during the cardiac cycle at REST | -determines the rate of blood through the systemic circuit

Question 32

Pulse Pressure

Answer 32

Difference between systolic & diastolic blood pressure

Question 33

Hypertension

Answer 33

High blood pressure | Rise above 140/90mmHG

Question 34

Mean Arterial BP is determined by:

Answer 34

1. Cardiac Output 2. Total Vascular Resistance Increase in determents = increase of MAP

Question 35

Blood Pressure Factors

Answer 35

- Cardiac Output - Blood Volume - Resistance to Flow - Blood Viscosity

Question 36

What regulates BP?

Answer 36

Acute: sympathetic NS Long-Term: kidneys -kidneys regulate BP by controlling blood volume

Question 37

Total Vascular Resistance

Answer 37

Sum of resistance to blood flow provided by ALL systemic blood vessels

Question 38

Increase in Arterial BP

Answer 38

Baroreceptors send impulses to the cardiovascular control center, which responses by decreasing sympathetic activity

Question 39

Decrease in Arterial BP

Answer 39

Reduction of baroreceptor activity to the brain, resulting in Cardiovascular Control Center increasing sympathetic outflow

Question 40

Sinoatrial Node (SA Node)

Answer 40

Pacemaker of the heart; electrical activity occurs Modified by: - parasympathetic NS - sympathetic NS

Question 41

Heart Rate Breakdown

Answer 41

HR increases at the beginning of exercise due to withdrawal of parasympathetic tone. At higher work rates, the increase in HR is achieved via an increased sympathetic outflow to the SA Nodes.

Question 42

Hemodynamics

Answer 42

The study of pressure, resistance, & flow of blood

Question 43

Blood Flow Resistance Factors

Answer 43

- length of the blood vessel - viscosity of the blood - RADIUS OF THE VESSEL Resistance = (length * viscosity) / Radius^4

Question 44

Greatest vascular resistance to blood flow

Answer 44

Occurs in the arterioles.

Question 45

Increased Oxygen Delivery to Exercising Skeletal Muscles is Accomplished by:

Answer 45

1. Increase in Cardiac Output | 2. Redistribution of blood flow from inactive organs to working muscle