Blood vessel

related topics
{disease, patient, cell}
{math, energy, light}
{island, water, area}
{line, north, south}

The blood vessels are the part of the circulatory system that transport blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.

Contents

Anatomy

The arteries and veins have different structures, veins having two layers and arteries having three.

  • Tunica intima (the thinnest layer): a single layer of simple squamous endothelial cells glued by a polysaccharide intercellular matrix, surrounded by a thin layer of subendothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina.
  • Tunica media (the thickest layer): circularly arranged elastic fiber, connective tissue, polysaccharide substances, the second and third layer are separated by another thick elastic band called external elastic lamina. The tunica media may (especially in arteries) be rich in vascular smooth muscle, which controls the caliber of the vessel.
  • Tunica adventitia: entirely made of connective tissue. It also contains nerves that supply the vessel

as well as nutrient capillaries (vasa vasorum) in the larger blood vessels.

Capillaries consist of little more than a layer of endothelium and occasional connective tissue.

When blood vessels connect to form a region of diffuse vascular supply it is called an anastomosis (pl. anastomoses). Anastomoses provide critical alternative routes for blood to flow in case of blockages.

Types

There are various kinds of blood vessels:

Full article ▸

related documents
Meconium
Trimethoprim
Proteinuria
Angiopathy
Non-Hodgkin lymphoma
Pathogen
Grey matter
Pharynx
Apraxia
Adrenal gland
Cowpox
Ampicillin
Perineum
Adrenocorticotropic hormone
Epidemic
Myalgia
Hemoglobinopathy
Ligament
Ileum
Hematology
Fragile X syndrome
Hirsutism
Fatal familial insomnia
Allergen
Prune belly syndrome
Streptococcus
Urology
Nicotinamide
Hepatology
Autism