Vasculogenesis is the process of

blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide awa ...

formation, occurring by a '' de novo'' production of

endothelial cell The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...

s. It is sometimes paired with

angiogenesis Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting ...

, as the first stage of the formation of the vascular network, closely followed by angiogenesis.

Process

In the

sense A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of Stimulus (physiology), stimuli. (For example, in the human body, the brain which is part of the cen ...

distinguished from

, vasculogenesis is different in one aspect: whereas angiogenesis is the formation of new blood vessels from pre-existing ones, vasculogenesis is the formation of new blood vessels, in

blood islands Blood islands are structures around the developing embryo which lead to many different parts of the circulatory system. Blood islands arise external to the developing embryo on the umbilical vesicle, allantois, connecting stalk and chorion. Th ...

, when there are no pre-existing ones. For example, if a

monolayer A monolayer is a single, closely packed layer of atoms, molecules, or cells. In some cases it is referred to as a self-assembled monolayer. Monolayers of layered crystals like graphene and molybdenum disulfide are generally called 2D materials. ...

endothelial cells The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...

begins sprouting to form

capillaries A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...

, angiogenesis is occurring. Vasculogenesis, in contrast, is when endothelial precursor cells (

angioblast Angioblasts (or vasoformative cells) are embryonic cells from which the endothelium of blood vessels arises. They are derived from embryonic mesoderm. Blood vessels first make their appearance in several scattered vascular areas that are develope ...

s) migrate and differentiate in response to local cues (such as growth factors and extracellular matrices) to form new blood vessels. These vascular trees are then pruned and extended through angiogenesis.

Occurrences

Vasculogenesis occurs during embryologic

development of the circulatory system The blood circulatory system is a organ system, system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascula ...

. Specifically, around blood islands, which first arise in the

mesoderm The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical E ...

of the yolk sac at 3 weeks of development. Vasculogenesis can also occur in the adult organism from circulating

endothelial progenitor cell Endothelial progenitor cell (or EPC) is a term that has been applied to multiple different cell types that play roles in the regeneration of the endothelial lining of blood vessels. Outgrowth endothelial cells are an EPC subtype committed to endot ...

s (derivatives of stem cells) able to contribute, albeit to varying degrees, to neovascularization. Examples of where vasculogenesis can occur in adults are: *

Tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

growth (see

HP59 HP59 is a pathologic angiogenesis capillary endothelial marker protein (7 or 12 transmembrane domains) which has been identified as the receptor for the Group B Streptococcal Toxin (GBS Toxin) molecule known as CM101, the etiologic agent for ear ...

) *

Revascularization In medical and surgical therapy, revascularization is the restoration of perfusion to a body part or organ that has had ischemia. It is typically accomplished by surgical means. Vascular bypass and angioplasty are the two primary means of reva ...

neovascularization Neovascularization is the natural formation of new blood vessels ('' neo-'' + '' vascular'' + '' -ization''), usually in the form of functional microvascular networks, capable of perfusion by red blood cells, that form to serve as collateral circu ...

after

trauma Trauma most often refers to: * Major trauma, in physical medicine, severe physical injury caused by an external source * Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event *Traumatic i ...

, for example, after

cardiac ischemia Coronary ischemia, myocardial ischemia, or cardiac ischemia,Potochny, Evy. "Cardiac Ischemia Symptoms." LiveStrong. Demand Media, 9 March 2010. Web. 6 Nov. 2010. is a medical term for a reduced blood flow in the coronary circulation through the ...

or retinal ischemia *

Endometriosis Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, f ...

- It appears that up to 37% of the microvascular endothelium of the ectopic endometrial tissue originates from

References

Embryology of cardiovascular system Cardiovascular physiology {{Circulatory-stub

Process

Occurrences

See also

References