Anatomy of Blood Vessels

These flashcards cover the key concepts related to the anatomy and function of blood vessels, including definitions of various types of blood vessels and their structural components.

Blood Vessels

The vessels that carry blood throughout the body; categorized into arteries, veins, and capillaries.

Arteries

Efferent vessels that carry blood away from the heart; typically have thicker walls and are more muscular than veins.

Veins

Efferent vessels that return blood to the heart; characterized by thinner walls compared to arteries.

Capillaries

Microscopic blood vessels that connect arteries and veins; specialized for exchange of materials with tissues.

Tunica Interna

The innermost layer of a blood vessel, consisting of endothelial cells that provide a smooth lining for blood flow.

Tunica Media

The middle layer of a blood vessel, composed of smooth muscle and elastic tissue, which regulates blood vessel diameter.

Tunica Externa

The outermost layer of a blood vessel, made of connective tissue that anchors the vessel and connects it to surrounding tissues.

Vasa Vasorum

Small vessels that supply blood to the walls of larger blood vessels, providing oxygen and nutrients.

Aneurysm

A weak point in an artery wall causing it to bulge; can be life-threatening if ruptured.

Arterioles

Small branches of arteries that lead to capillaries; major regulators of blood flow and pressure.

Post Capillary Venules

Smallest veins that receive blood from capillaries and are more porous, allowing for fluid exchange with surrounding tissues.

Venous Valves

One-way valves within veins that prevent backflow of blood and assist in venous return to the heart.

Capillary Beds

Networks of capillaries where the exchange of materials occurs between blood and tissues.

Sphincters

Smooth muscle cells that encircle capillary entrances and regulate blood flow into capillaries.

Microvasculature

The network of capillaries and small blood vessels where exchange of nutrients, gases, and wastes occurs.

Continuous Capillaries

Capillaries with uninterrupted endothelial linings, allowing selective passage of small molecules.

Fenestrated Capillaries

Capillaries with pores that increase permeability, allowing faster exchange of substances; found in kidneys and endocrine glands.

Sinusoids

Wider, irregular capillaries found in the liver and spleen, allowing passage of larger molecules and cells.

Anastomosis

Connection between two blood vessels, which can provide alternative pathways for blood flow.

Portal System

A vascular arrangement where blood flows through two consecutive capillary networks before returning to the heart.

Baroreceptors

Sensory receptors located in the walls of arteries that help monitor blood pressure and regulate heart rate.

Chemoreceptors

Sensory receptors that detect changes in blood chemistry, such as pH or gas levels.