PE flashcards

Typical resting heart rate ($HR$) for an untrained adult

$$70-72\,\text{bpm}$$

Typical resting stroke volume ($SV$) for an untrained adult

$$70\,\text{mL}$$

Formula and typical resting value for cardiac output ($Q$)

$Q = HR \times SV$, approximately $5.0\,\text{L\,min}^{-1}$

Autonomic branch controlling the heart at rest

Parasympathetic nervous system via the vagus nerve

Neurotransmitter that decreases resting heart rate

Acetylcholine ($\text{ACh}$)

Order of the cardiac conduction pathway

$$\text{SAN} \rightarrow \text{AVN} \rightarrow \text{Bundle of His} \rightarrow \text{Bundle branches} \rightarrow \text{Purkinje fibres}$$

Reason for the delay at the atrioventricular node ($\text{AVN}$)

Allows the atria to fully empty into the ventricles before ventricular contraction begins

Resting bradycardia

A resting heart rate below $60\,\text{bpm}$

Why trained endurance athletes maintain normal resting cardiac output despite a lower heart rate

They possess a larger stroke volume ($SV$) due to cardiac hypertrophy

Cardiac diastole

The relaxation phase of the heart chambers where passive blood filling occurs

what is the definition of stroke volume?

the volume of blood pumped by the left ventricle per contraction(beat)

what is the definition of cardiac output?

Cardiac output is the total volume of blood pumped by the heart per minute

what is the definition of heart rate

number of times the heart beats in a minute

what is cardiac systole?

Cardiac output is the total volume of blood pumped by the heart per minute, typically

what is myogenic

the hearts capacity to generate its own electrical impulse to trigger cardiac contraction.

what is atrial systole?

Atrial systole is the brief period of the cardiac cycle when the upper chambers of the heart (the atria) contract to force the remaining blood down into the lower chambers (the ventricles).