Blood Vessels I

Flashcards for key vocabulary related to blood vessels and circulation.

Arteries

Carry blood away from the heart.

Veins

Carry blood back towards the heart.

Capillaries

Major sites of exchange where oxygen and nutrients are dropped off and waste and CO2 are picked up.

Tunica Interna

The inner layer of a blood vessel, lining the lumen and consisting of simple squamous epithelium.

Endothelium

Simple squamous epithelium that lines all blood vessels.

Tunica Media

The middle layer of a blood vessel, composed mostly of smooth muscle to control vessel diameter.

Tunica Externa (Adventitia)

The outer layer of a blood vessel, anchoring it to surrounding tissues and serving as a nutrient layer.

Arterioles

Smallest arteries that feed blood to the capillary networks.

Metarterioles

Vessels capable of bypassing capillary networks.

Venules

Smallest vessels on the venous side that receive blood from capillaries.

Precapillary Sphincters

Rings of smooth muscle that regulate blood flow into capillary beds.

Vascular Shunt

A direct connection between an arteriole and a venule, bypassing the capillary bed.

Anastomosis

An alternative pathway for blood flow.

Continuous Capillaries

Capillaries with intercellular clefts, allowing for standard exchange of small molecules.

Fenestrated Capillaries

Capillaries with fenestrations (windows) that increase permeability for filtration and reabsorption.

Sinusoids

Capillaries with large gaps between endothelial cells, allowing for the passage of large proteins and cells.

Portal System

Specialized blood vessels consisting of two capillary beds in series, connected by a portal vein.

Baroreceptors

Arteries pressure receptors located in the aortic arch and carotid sinus that detect changes in blood pressure.

Hypertension

Sustained resting arterial blood pressure of 140/90 mm Hg or higher.