Alterations in Blood Pressure - Key Vocabulary

Vocabulary flashcards covering fundamental terms and concepts involved in blood pressure regulation, hypertension, and hypotension as presented in the lecture notes.

Arterial Blood Pressure

Pressure exerted by circulating blood upon the walls of arteries, generated primarily by left ventricular contraction overcoming aortic resistance.

Cardiac Output (CO)

The volume of blood the heart pumps per minute; calculated as stroke volume (SV) multiplied by heart rate (HR).

Stroke Volume (SV)

The amount of blood ejected by the ventricle with each heartbeat; major determinant of systolic pressure.

Heart Rate (HR)

Number of heartbeats per minute; when multiplied by stroke volume gives cardiac output.

Systemic Vascular Resistance (SVR)

The resistance the left ventricle must overcome to eject blood, determined by arterial radius and vessel compliance; major determinant of diastolic pressure.

Blood Pressure (BP) Equation

BP = CO × SVR, showing that arterial pressure results from cardiac output and systemic vascular resistance.

Preload

End-diastolic volume—the volume of blood in ventricles at the end of diastole; influenced by venous return.

Afterload

The pressure or resistance the ventricle must overcome to circulate blood; increases with hypertension and vasoconstriction.

Systolic Blood Pressure

Peak arterial pressure during cardiac systole; influenced mainly by stroke volume.

Diastolic Blood Pressure

Lowest arterial pressure during cardiac diastole; influenced mainly by systemic vascular resistance.

Pulse Pressure

Difference between systolic and diastolic pressures (SBP − DBP).

Mean Arterial Pressure (MAP)

Average pressure in the arteries during one cardiac cycle; approximated by [(2 × DBP) + SBP] ÷ 3.

Korotkoff Sounds

Auditory sounds heard via stethoscope during BP measurement; onset marks systolic pressure and disappearance marks diastolic pressure.

Direct BP Measurement

Invasive technique using an intra-arterial catheter, often in the radial artery, providing the most accurate blood pressure readings.

Baroreceptors

Stretch receptors in carotid sinus and aortic arch that sense pressure changes and trigger reflexes to adjust BP via autonomic pathways.

Baroreflex

Rapid, short-term reflex that alters heart rate and vascular tone through sympathetic and parasympathetic activity to stabilize blood pressure.

Short-Term BP Regulation

Seconds-to-minutes control mediated by baroreceptors, vasomotor center, and autonomic nervous system adjusting HR and SVR.

Long-Term BP Regulation

Hours-to-days control involving kidneys, hormonal systems (RAAS, ADH, natriuretic peptides) and vascular remodeling to manage blood volume and SVR.

Renin–Angiotensin–Aldosterone System (RAAS)

Hormonal cascade beginning with renin release, producing angiotensin II (vasoconstriction) and aldosterone (sodium/water retention), raising BP.

Angiotensin II

Potent vasoconstrictor produced in RAAS; increases SVR, stimulates aldosterone and vasopressin release, and promotes vascular hypertrophy.

Antidiuretic Hormone (ADH)

Pituitary hormone that increases water reabsorption in kidneys, expanding blood volume and raising blood pressure.

Nitric Oxide

Endothelial-derived relaxing factor that causes vasodilation and thus lowers systemic vascular resistance.

Primary (Essential) Hypertension

Most common form of high blood pressure with no identifiable cause; associated with modifiable and non-modifiable risk factors.

Secondary Hypertension

Elevated blood pressure caused by an identifiable condition, drug, or pathology; more common in children.

Isolated Systolic Hypertension

Subtype where only systolic BP is elevated while diastolic remains normal; common in older adults.

Hypertensive Crisis

Severe BP elevation (often DBP >120 mm Hg) with symptoms of end-organ damage; requires immediate parenteral therapy.

Hypertensive Urgency

Severe BP elevation without end-organ damage; managed with oral agents over 24–48 hours.

Orthostatic (Postural) Hypotension

Drop in SBP ≥20 mm Hg or DBP ≥10 mm Hg within 3 minutes of standing, often with dizziness or syncope.

DASH Diet

Dietary Approaches to Stop Hypertension; emphasizes fruits, vegetables, low-fat dairy, and reduced sodium to lower BP.

Atherosclerosis

Arterial disease characterized by plaque buildup; risk is increased by hypertension and high LDL cholesterol.

Modifiable Hypertension Risk Factors

Lifestyle elements such as obesity, high sodium intake, alcohol use, inactivity, and obstructive sleep apnea that can be altered to lower BP.

Natriuretic Peptides

Hormones (e.g., ANP, BNP) released by heart that promote sodium excretion and vasodilation, aiding long-term BP control.

Left Ventricular Hypertrophy

Thickening of the left ventricular muscle due to chronic high workload, a common consequence of longstanding hypertension.