Histology of Circulatory System

Flashcards about the histology of the circulatory system.

Cardiovascular System

Two-way transport system.

Lymphatic Vascular System

One-way transport system.

Lymph Vascular System

Network of drainage vessels returning excess extravascular fluid to the blood circulatory system.

Arterial System

Distribution network to the tiny peripheral microcirculation.

Venous System

Carries blood from the capillary system back to the heart.

Tunica Intima

Inner lining of the circulatory system with endothelium, basement membrane, and collagenous tissue.

Tunica Media

Intermediate, predominantly muscular layer of the circulatory system.

Tunica Adventitia

Outer, principally supporting tissue layer of the circulatory system.

Arteries

Carry blood away from the heart.

Elastic Arteries

Major distribution vessels with concentric layers of elastic membranes.

Muscular Arteries

Main distributing branches of the arterial tree.

Arterioles

Terminal branches of the arterial tree supplying capillary beds.

Vasa Vasorum

Arterioles, capillaries, and venules in the adventitia and outer part of the media.

Aneurysm

Sac-like dilation of the wall of an artery resulting from weakness.

Atherosclerosis

Disease in which lipid material infiltrates the tunica intima.

Carotid Sinus

Baroreceptor in the internal carotid artery perceiving changes in blood pressure.

Carotid Body

Chemoreceptor monitoring changes in oxygen and carbon dioxide levels.

Aortic Bodies

Located on the arch of the aorta, similar in structure and function to carotid bodies.

Microcirculation

Part of the circulatory system for exchange of gases, fluids, nutrients, and waste products.

Capillaries

Extremely thin-walled vessels forming an interconnected network.

Pericytes

Located along the outside of capillaries and small venules, regulating blood flow

Continuous Capillaries

Capillaries with no pores or fenestrae in their walls.

Fenestrated Capillaries

Capillaries possessing pores (fenestrae) in their walls covered by pore diaphragms.

Sinusoidal Capillaries

Capillaries with discontinuous endothelial cells and basal lamina, and many large fenestrae.

Veins

Vessels that return blood to the heart.

Valves of Veins

Prevent the backflow of blood, abundant in the veins of the legs.

Varicose Veins

Abnormally enlarged tortuous veins, usually in the legs.

Endocardium

Simple squamous epithelium lining the lumen of the heart.

Myocardium

Thick middle layer of the heart composed of cardiac muscle cells.

Sinoatrial Node (Pacemaker)

Specialized nodal cardiac muscle cells that can spontaneously depolarize, creating an impulse.

Purkinje Fibers

Large, modified cardiac muscle cells that transmit impulses to the cardiac muscle cells.

Atrial Wall Cells

Specialized cardiac muscle cells producing peptides for fluid maintenance and electrolyte balance.

Epicardium

Outermost layer of the heart wall, also called the visceral layer of the pericardium

Pericarditis

Infection in the pericardial cavity restricting the heart from beating properly.

Cardiac Skeleton

Structural framework for the heart, providing attachment sites for cardiac muscle.

Lymphatic Vascular System

Vessels that collect the excess interstitial fluid and return it to the cardiovascular system.