The amount of blood ejected by each ventricular contraction is called the?

Appeared in: JODHPUR AIIMS SNO-2018

Explanation

Stroke volume is the precise term for the volume of blood ejected from a ventricle during one contraction (systole).
In a healthy adult, the normal stroke volume is approximately 50 to 75 mL per contraction.
This is a measure of volume per beat, which distinguishes it from cardiac output, a measure of volume per minute.

Option A: Cardiac output represents the total volume of blood pumped by the heart over one minute, not during a single contraction.
Option C: Tidal volume is a respiratory term, referring to the amount of air that moves in and out of the lungs during a normal, quiet breath.
Option D: Expiratory reserve volume is a respiratory term for the additional amount of air that can be forcefully exhaled after a normal exhalation.

Clinical Relevance

Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Definition of Stroke Volume in acute care settings.
Nurses indirectly assess stroke volume by monitoring a patient's pulse quality (strong vs. weak), blood pressure, urine output, and mental status. A weak, thready pulse can indicate a low stroke volume.
Conditions like heart failure, hypovolemia (low blood volume), and myocardial infarction can significantly decrease stroke volume, leading to compromised organ perfusion.
What if? A patient has a normal heart rate but is showing signs of poor perfusion (e.g., confusion, low urine output). This could indicate a critically low stroke volume. The nurse's priority is to assess for causes like dehydration or bleeding and report findings urgently, as the body may not be able to compensate for long.

How to Approach the Question

First, analyze the keywords in the question: 'amount of blood' and 'each ventricular contraction'. This specifies a single heartbeat event.
Next, evaluate the options. Identify that 'Tidal volume' and 'Expiratory reserve' are related to the respiratory system and can be eliminated as they deal with air, not blood.
Differentiate between the two remaining cardiovascular terms. 'Cardiac output' is a measure of flow over time (per minute).
'Stroke volume' is a measure of volume per event (per 'stroke' or beat).
Match the question's focus on a single 'contraction' with the definition of 'Stroke volume' to select the correct answer.

Concept Tested & Keywords

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E6 Nursing Fundamentals Potter Perry 12e Part 4 p. 231-233

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 683-685

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