Blood Flow, Pressure & Resistance

These flashcards cover key concepts related to blood flow, pressure, resistance, and the composition of blood, providing important terminology and definitions relevant to the lecture on the cardiovascular system.

Blood Flow

Volume of blood flowing through a vessel, organ, or entire circulation in a given time (ml/min).

Blood Pressure

Force per unit area exerted on vessel wall by contained blood (mmHg).

Mean Arterial Pressure (MAP)

Overall blood pressure measured in a large distributing artery of the systemic circuit; influenced by cardiac output and vascular resistance.

Vasoconstriction

Narrowing of blood vessels, which increases resistance and Mean Arterial Pressure (MAP).

Vasodilation

Widening of blood vessels, which decreases resistance and can increase local blood flow.

Resistance

Opposition to blood flow due to friction against blood vessel walls, influenced by vessel length, viscosity, and diameter.

Hemoglobin

Protein in red blood cells that carries oxygen; composed of four polypeptide chains.

Erythropoiesis

Production of red blood cells, stimulated by erythropoietin in response to low oxygen levels.

Hematocrit

Percentage of blood volume occupied by red blood cells; useful for diagnosing conditions like anemia and polycythemia.

Baroreceptors

Mechanoreceptors that detect changes in blood pressure, located in carotid sinus and aortic arch.

Chemoreceptors

Sensors that monitor blood levels of oxygen, carbon dioxide, and pH; involved in respiratory regulation.

Plasma

Fluid portion of blood, making up 55-58% of blood volume, containing water, electrolytes, and proteins.

Auto regulation

Intrinsic mechanisms by which blood flow to specific tissues is regulated based on local conditions.

ABO blood group

Classification of blood based on the presence of antigens on the surface of red blood cells.

Rh factor

Protein on the surface of red blood cells that determines whether blood type is classified as positive or negative.

Myogenic (Intrinsic auto regulation)

direct response of vascular smooth muscle to changes in pressure. used to keep blood flow fairly constant in a particular tissue/organ during normal conditions.

Metabolic control

localized vasodilation or vasoconstriction due to metabolic activity of target tissue/organ/region. used to change blood flow in a particular tissue/organ/region to match altered metabolic activity