242-245

Question 1

Define Cardiac Output (equation as well)

Answer 1

• is a measure of the volume of blood the heart pumps per minute
• CO = HR x SV
• CO = Cardiac Output (measured in liters per minute, L/min)
• HR = Heart Rate (the number of beats per minute, bpm)
• SV = Stroke Volume (the amount of blood pumped by the heart with each beat, measured in milliliters, mL)

Question 2

What is stroke volume?

Answer 2

Blood ejected from the left ventricle in one beat (mL)

Question 3

During exercise, venous return increases as a result of what 4 factors?

Answer 3

• Constriction of the veins (vasoconstriction)
• Skeletal muscle pump
• Thoracic pump
• Nervous stimulation of the heart

Question 4

Define Ejection Fraction

Answer 4

• The proportion of blood that is ejected from the left ventricle during a single heartbeat
• Average: At rest, approx. 50-60% and increases during exercise (increases to approx. 85%)

Question 5

Define Heart Rate

Answer 5

• Number of times the heart contracts in 1 min
• Q = SV x HR

Question 6

What is the Cardiac Cycle?

Answer 6

Series of events that occur during one heartbeat (systolic and diastole phase).

Question 7

Differentiate between systolic and diastolic pressure

Answer 7

• Systolic: Refers to the maximum pressure seen in the arteries during the contraction phase of the ventricle (120 mmHg)
• Diastolic: The minimum pressure seen in the arteries during the relaxation phase of the ventricle (80 mmHg)

Question 8

What is hypertension? What blood pressure indicates high blood pressure or above

Answer 8

• Hypertension is a condition in which the force of blood against the walls of the arteries is consistently too high.
• Pressure greater than 140/90 mmHg is high

Question 9

Explain why and how the body changes blood flow distribution based on physical activity

Answer 9

• During exercise, blood flow changes to support active muscles.
• More blood goes to muscles for extra oxygen (O₂) and nutrients.
• Blood flow to the skin increases to help cool the body.
• Less blood goes to non-essential organs, like the digestive system.
• The cardiovascular system widens blood vessels in active areas and narrows them in less active areas.
• This helps keep muscles working well by providing oxygen and removing waste.