Blood Pressure and Circulatory Regulation - Vocabulary Flashcards

Vocabulary flashcards covering key terms and definitions from the lecture notes on blood pressure, arterial pressure components, and short-term regulatory mechanisms.

Systolic Pressure

The highest arterial pressure during ventricular systole (example: ~120 mmHg).

Diastolic Pressure

The lowest arterial pressure during ventricular diastole (example: ~80 mmHg).

Pulse Pressure

The difference between systolic and diastolic pressures (e.g., 120 − 80 = 40 mmHg).

Mean Arterial Pressure (MAP)

The average arterial pressure in one cardiac cycle; driving force for tissue perfusion; MAP ≈ CO × TPR and MAP ≈ Diastolic + 1/3 Pulse Pressure.

Cardiac Output (CO)

Volume of blood pumped by the heart per minute; CO = Stroke Volume × Heart Rate.

Stroke Volume

Volume of blood ejected by the ventricle with each beat; influenced by preload, contractility, and afterload.

Heart Rate (HR)

Number of heartbeats per minute; contributes to cardiac output.

Total Peripheral Resistance (TPR)

Resistance to blood flow offered by the systemic circulation, mainly by arterioles; affects MAP.

Blood Volume

Total amount of blood in the circulatory system; changes MAP; regulated by kidneys and fluid balance.

Venous Return

Blood flow back to the heart; increases preload and stroke volume; can be modulated by venoconstriction.

Venous Reservoir

Veins hold about 60% of total blood; can supply blood to the arterial system to aid maintaining MAP.

Preload

Initial ventricular filling/stretch; proportional to venous return and end-diastolic volume; influences stroke volume.

Baroreceptors

Stretch receptors in the aortic arch and carotid sinuses that detect BP and continuously send signals to the brainstem.

Baroreceptor Reflex

Short-term BP regulation pathway: baroreceptors → cardiovascular center → autonomic outputs to heart and vessels to restore BP.

Medullary Cardiovascular Control Center

Brainstem (medulla) center that integrates baroreceptor input and modulates sympathetic and parasympathetic output.

Sympathetic Nervous System Effect on BP

Increases heart rate and contractility; causes vasoconstriction; raises BP; can also cause venoconstriction to boost venous return.

Parasympathetic Nervous System Effect on BP

Decreases heart rate (mainly via the SA node) and can reduce contractility; lowers BP.

Poiseuille’s Law (Flow Relationship)

Blood flow is directly proportional to the pressure difference and inversely proportional to resistance; simplified as ΔP/Resistance.

Pressure Gradient

The pressure difference driving blood flow; blood moves from higher to lower pressure.