Blood flow & Pressure

Question 1

What is blood flow?

Answer 1

The volume of blood flowing through a vessel or organ in a given period, measured in mL/min.

Question 2

What factors influence blood flow and pressure?

Answer 2

Cardiac output, compliance, blood volume, viscosity, and vessel length/diameter.

Question 3

What is circulation time?

Answer 3

The time it takes a drop of blood to travel through pulmonary and systemic circuits (about 1 minute).

Question 4

What is laminar flow?

Answer 4

Smooth, orderly flow of blood along the vessel walls.

Question 5

What is turbulent flow?

Answer 5

Irregular flow with disruption, often at vessel branches; can be heard as murmurs or bruits.

Question 6

Where is blood flow velocity slowest?

Answer 6

In capillaries, to allow for exchange of gases, nutrients, and wastes.

Question 7

What is systolic pressure?

Answer 7

The peak arterial pressure during ventricular contraction.

Question 8

What is diastolic pressure?

Answer 8

The lowest arterial pressure during ventricular relaxation.

Question 9

What is pulse pressure?

Answer 9

Difference between systolic and diastolic pressures.

Question 10

What is MAP (mean arterial pressure)?

Answer 10

Diastolic pressure + 1/3(pulse pressure); average pressure in arteries.

Question 11

What factors affect MAP?

Answer 11

Cardiac output, resistance, and blood volume.

Question 12

What is vascular resistance?

Answer 12

Opposition to blood flow due to friction between blood and vessel walls.

Question 13

How does vessel diameter affect resistance?

Answer 13

Resistance is inversely proportional to the fourth power of diameter.

Question 14

What increases blood viscosity?

Answer 14

Higher hematocrit or plasma protein levels.

Question 15

How does blood vessel length affect resistance?

Answer 15

Longer vessels increase resistance and blood pressure.

Question 16

What is the role of the autonomic nervous system (ANS) in cardiovascular control?

Answer 16

It adjusts heart rate, contractility, and vessel diameter.

Question 17

What are the three cardiovascular reflexes?

Answer 17

Baroreceptor, proprioceptor, and chemoreceptor reflexes.

Question 18

Where are baroreceptors located?

Answer 18

Carotid sinus and aortic arch.

Question 19

What do baroreceptors respond to?

Answer 19

Changes in stretch due to blood pressure.

Question 20

What do proprioceptors detect?

Answer 20

Joint angle and muscle stretch, signaling the onset of movement.

Question 21

What do chemoreceptors detect?

Answer 21

Changes in blood oxygen, CO₂, and pH.

Question 22

How does the cardiovascular center respond to low BP?

Answer 22

Increases sympathetic output, decreases parasympathetic stimulation.

Question 23

What is the role of renin-angiotensin-aldosterone (RAA) system?

Answer 23

Raises BP via vasoconstriction and increased blood volume.

Question 24

What does aldosterone do?

Answer 24

Increases sodium and water reabsorption by the kidneys.

Question 25

What do epinephrine and norepinephrine do?

Answer 25

Increase heart rate and contractility, vasoconstrict most vessels.

Question 26

What does ADH (vasopressin) do?

Answer 26

Promotes water reabsorption and vasoconstriction, raising BP.

Question 27

What does atrial natriuretic peptide (ANP) do?

Answer 27

Lowers BP by promoting sodium/water excretion and vasodilation.

Question 28

What does erythropoietin (EPO) do?

Answer 28

Stimulates RBC production in response to low oxygen.

Question 29

What is shock?

Answer 29

A failure of the cardiovascular system to deliver enough oxygen and nutrients to meet tissue needs.

Question 30

What are the signs of shock?

Answer 30

Low BP, rapid pulse, pale/cool skin, low urine output, thirst, confusion.

Question 31

What are the four types of shock?

Answer 31

Hypovolemic, cardiogenic, vascular, and obstructive.

Question 32

What is hypovolemic shock?

Answer 32

Caused by loss of blood or fluid volume.

Question 33

What is cardiogenic shock?

Answer 33

Caused by heart failure to pump effectively.

Question 34

What is vascular shock?

Answer 34

Due to excessive vasodilation and drop in resistance.

Question 35

What is obstructive shock?

Answer 35

Caused by a physical blockage to blood flow (e.g., pulmonary embolism).

Question 36

How does the RAA system respond to shock?

Answer 36

Raises BP through vasoconstriction and water retention.

Question 37

How does sympathetic stimulation help in shock?

Answer 37

Increases HR, contractility, and vasoconstriction.

Question 38

What role do local vasodilators play in shock?

Answer 38

Increase flow to hypoxic tissues but may worsen hypotension systemically.