Cardiovascular System and Blood Vessel Dynamics

Flashcards covering blood vessel structure, circulatory routes, pressure dynamics, viscosity, and neural regulation based on the lecture transcript.

Veins

The only blood vessels in the body that contain valves to prevent the backflow of blood.

Direct path of circulatory blood flow

The sequence of blood flow from the heart: conducting arteries to distributing arteries, resistance arteries, arterioles, capillaries, venules, muscular veins, medium veins, large veins, and back to the heart.

Portal system

A circulatory route containing two capillary beds in series connected by a portal vein before returning blood to the heart.

Hepatic portal vein

A portal vein located between the capillary beds of the intestines and the liver that carries absorbed substances to the liver.

Anastomosis

A converging point or interconnection between two blood vessels.

Arteriovenous anastomosis

A vessel pathway (shunt) that connects an arteriole directly to a venule, bypassing a capillary bed.

Arterial anastomosis

A connection where multiple arteries merge to supply blood to the same region, providing alternative collateral pathways in case of a blockage.

Venous anastomosis

Interconnections between veins that allow blood to take alternative routes out of tissues, commonly found around joints where vessel compression occurs.

Perfusion

The targeted delivery and routing of blood flow to specific functional areas within an organ or tissue based on active demand.

Systolic blood pressure

The upper blood pressure reading, measured as the heart actively contracts and first forces blood past the cuff pressure.

Diastolic blood pressure

The lower blood pressure reading, measured when the heart relaxes between beats and the vessel sounds disappear.

Hypertension

A clinical condition of high blood pressure defined as a reading of $140/90$ or higher.

Hypotension

A clinical condition of low blood pressure defined as dropping below a reading of $90/60$.

Blood viscosity

The thickness or internal friction of blood, determined primarily by the concentrations of albumin and red blood cells.

Polycythemia

An excess of red blood cells in the blood, which increases blood viscosity and raises blood pressure.

Anemia

A deficiency of red blood cells, which decreases blood viscosity and lowers blood pressure.

Vasoreflexes

Changes in vessel diameter caused by the contraction or relaxation of smooth muscle within the tunica media.

Vasodilation

The widening of a blood vessel lumen when its smooth muscle layer relaxes, decreasing resistance to blood flow.

Vasoconstriction

The narrowing of a blood vessel lumen when its smooth muscle layer contracts, increasing resistance to blood flow.

Autoregulation

The localized process where active tissues adjust their own blood supply by releasing chemical factors or reacting to metabolic wastes to dilate or constrict nearby vessels.

Carotid sinuses

Structures in the internal carotid arteries containing stretch receptors that monitor blood pressure going to the brain.

Glossopharyngeal nerve

The sensory nerve wrapped around the carotid sinus that transmits stretch signals and pressure information to the medulla oblongata.