Regulation of Blood Pressure & Blood Flow – Key Vocabulary

These vocabulary flashcards cover the neural, hormonal, and renal mechanisms of blood-pressure regulation, as well as related clinical conditions and blood-flow concepts discussed in the lecture notes.

Blood Pressure (BP)

The force that blood exerts on the arterial walls, measured in millimeters of mercury (mm Hg).

Short-Term Neural Control

Rapid regulation of BP through nervous system reflexes that alter vessel diameter and cardiac output.

Vasoconstriction

Narrowing of blood vessels that increases peripheral resistance and raises blood pressure.

Vasodilation

Widening of blood vessels that decreases peripheral resistance and lowers blood pressure.

Medulla Oblongata

Brainstem region housing cardiovascular centers that integrate baroreceptor and chemoreceptor input.

Vasomotor Center

Portion of the medulla that controls blood vessel diameter via sympathetic efferent fibers.

Cardioacceleratory Center

Medullary center that increases heart rate and contractility, boosting cardiac output.

Cardioinhibitory Center

Medullary center that decreases heart rate, reducing cardiac output.

Baroreceptors

Stretch‐sensitive pressure receptors in the carotid sinuses and aortic arch that detect changes in arterial BP.

Chemoreceptors

Receptors in the aortic arch and large neck arteries that respond to high CO₂, low pH, or low O₂.

Higher Brain Centers

Hypothalamic regions that modify cardiovascular activity during exercise, temperature change, and emotions.

Peripheral Resistance (TPR)

Opposition to blood flow in the systemic circulation, chiefly influenced by arteriolar diameter.

Cardiac Output (CO)

Volume of blood the heart pumps per minute; product of heart rate × stroke volume.

Short-Term Hormonal Control

Endocrine mechanisms that quickly adjust BP by altering CO or TPR.

Adrenal Medulla Hormones

Epinephrine and norepinephrine released during stress that increase CO and produce vasoconstriction.

Epinephrine

Adrenal hormone that acts on β₁ receptors of the heart to raise heart rate and contractility.

Norepinephrine

Adrenal hormone that primarily causes α-mediated vasoconstriction of arterioles.

Angiotensin II

Potent vasoconstrictor formed in the renin-angiotensin pathway; raises BP and stimulates aldosterone.

Antidiuretic Hormone (ADH)

Posterior pituitary hormone that promotes water reabsorption; at high levels it also causes vasoconstriction.

Atrial Natriuretic Peptide (ANP)

Atrial hormone that lowers BP by promoting salt and water loss and causing vasodilation.

Long-Term Renal Regulation

Slow BP control via the kidneys by adjusting blood volume through direct and indirect mechanisms.

Direct Renal Mechanism

Kidney response that alters urine output directly to influence blood volume and BP.

Renin-Angiotensin-Aldosterone System (RAAS)

Indirect renal pathway that increases blood volume and vasoconstriction to elevate BP.

Hypertension

Chronic resting BP ≥ 140/90 mm Hg; major risk factor for cardiovascular and renal disease.

Primary Hypertension

High BP with no identifiable cause; accounts for about 90 % of cases.

Secondary Hypertension

Elevated BP due to identifiable disorders such as renal artery obstruction or endocrine disease.

Hypotension

Resting BP below 90/60 mm Hg; problematic if it leads to inadequate tissue perfusion.

Orthostatic Hypotension

Temporary BP drop and dizziness upon standing due to delayed vascular adjustment.

Circulatory Shock

Condition in which blood vessels are inadequately filled, compromising tissue perfusion.

Hypovolemic Shock

Shock resulting from large-scale blood or fluid loss.

Vascular Shock

Shock caused by extreme vasodilation and a sharp fall in peripheral resistance.

Cardiogenic Shock

Shock occurring when the heart cannot sustain adequate circulation.

Tissue Perfusion

Blood flow through body tissues, delivering oxygen/nutrients and removing wastes.

Intrinsic (Autoregulation) Control

Local adjustment of blood flow to match a tissue’s immediate metabolic needs.

Extrinsic Control

Systemic regulation of blood flow via sympathetic nerves and circulating hormones.