Biomaterial Database

On the fine structure of arc-capillaries: true a.v. anastomoses or sphincter capillaries? 1990

R Leiderer, and F Hammersen

Department of Anatomy, Technical University of Munich, Federal Republic of Germany.

The arc-capillaries represent vessels of the terminal bed: they are not true arterio-venous anastomoses. They exhibit a typical capillary structure of their wall. The existence of smooth muscle cells and modified smooth muscle cells, such as epithelioid cells, cannot be demonstrated. Likewise, a specific activation by nerves does not exist. The arc-capillaries differ from the net-capillaries neither in the structure of their wall nor in diameter. At the origin of the arc-capillaries from the final arteriole there are no smooth muscle cells, only pericytes (adventitial cells). The arc-capillaries branch off where the final arteriole no longer possesses smooth muscle cells. The electron microscopic studies showed that arc-capillaries do not represent sphincter capillaries.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002196	Capillaries	The minute vessels that connect arterioles and venules.	Capillary Beds,Sinusoidal Beds,Sinusoids,Bed, Sinusoidal,Beds, Sinusoidal,Capillary,Capillary Bed,Sinusoid,Sinusoidal Bed
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004388	Dura Mater	The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.	Falx Cerebelli,Falx Cerebri,Pachymeninx,Tentorium Cerebelli
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001163	Arteriovenous Anastomosis	A vessel that directly interconnects an artery and a vein, and that acts as a shunt to bypass the CAPILLARY BEDS. Not to be confused with SURGICAL ANASTOMOSIS or ARTERIOVENOUS FISTULA.	Arteriovenous Anastomoses,Anastomose, Arteriovenous,Anastomoses, Arteriovenous,Anastomosis, Arteriovenous,Arteriovenous Anastomose