Blood Circulation and Blood Vessels

Vocabulary practice flashcards covering the components of the circulatory system, blood vessel types, and blood distribution based on Dr. Mike's lecture.

Systemic circulation

The pathway of circulation originating from the left side of the heart that delivers oxygen, nutrients, and hormones to the tissues of the body and removes metabolic waste.

Pulmonary circulation

The pathway of circulation where blood leaves the right side of the heart and travels to the lungs.

Total blood volume

The total volume of blood in the human body, typically comprising about $7\%$ of body weight, or roughly $5\text{ liters}$.

Arteries

Blood vessels that lead away from the heart ventricles under the highest pressure, possessing extensive elastic tissue to stretch and snap back during heart contractions.

Elastic vessels

A functional classification for arteries characterized by abundant elastic tissue that allows them to stretch under high pressure and snap back.

Arterioles

The smallest terminal branches of arteries that are wrapped in smooth muscle to redirect and deliver blood under various pressures depending on tissue demand.

Resistance vessels

A functional classification for arterioles due to the smooth muscle in their walls, which constricts or dilates to regulate blood pressure and redirect flow.

Capillary beds

Microscopic vessel networks that act as the primary site of exchange between the blood and tissues for oxygen, nutrients, gases, and metabolic waste.

Venules

Vessels situated immediately after the capillary beds that collect deoxygenated, nutrient-depleted, and waste-rich blood before draining into veins.

Veins

Thin-walled vessels containing a small amount of smooth muscle that collect blood returning to the heart and possess a massive capacity to stretch and store blood.

Capacitance vessels

A functional classification for venules and veins because of their thin walls and high capacity to stretch, hold blood, and act as a reservoir.

Blood reservoir

The functional storage role filled primarily by veins and venules, which accommodate approximately $64\%$ of the body's blood volume at any given moment.

Noradrenaline

The chemical messenger delivered by the sympathetic branch of the autonomic nervous system to signal arteriole smooth muscle to constrict.