Midterm C8 learning from my mistakes

Question 1

explain stroke volume (SV) and its role during exercise.”

Answer 1

SV increases with intensity but plateaus at ~40-60% VO2 max. It does not decrease unless fatigue, dehydration, or excessive cardiovascular strain occurs.

Question 2

How does cardiac output (CO) change during prolonged exercise?”

Answer 2

CO remains stable or increases due to rising HR, even if SV declines due to dehydration or cardiovascular drift.

Question 3

What physiological factors contribute to an increase in blood pressure at the start of exercise?”

Answer 3

increased cardiac output and sympathetic vasoconstriction.

Question 4

What is ventilatory drift, and what causes it?”

Answer 4

increased body temperature and catecholamines (EP & NE)

Question 5

What are the main stimuli for increased ventilation during exercise?”

Answer 5

increased CO2, acidosis (H+ buildup), epinephrine/norepinephrine,
and body temperature.

Question 6

Define ventilatory threshold 1 and ventilatory threshold 2.”

Answer 6

VT1 is when ventilation increases disproportionately to oxygen uptake, signaling anaerobic metabolism.

VT2 (respiratory compensation point) occurs when buffering of acid (H+) leads to excessive CO2 production, forcing rapid ventilation.

Question 7

How much can cardiac output increase during maximal exercise?”

Answer 7

CO is measured in L/min. During max exercise, CO can increase to 25-40 L/min.

Question 8

“What are three compensatory methods the cardiovascular system uses to meet increased metabolic demands during exercise?”

Answer 8

1. Increase CO (HR & SV contribute)
2. Redistribute blood flow (vasodilation in muscles, vasoconstriction in inactive tissues)
3. Increase oxygen extraction (more O2 taken from blood per unit volume)