The trabecular arteries are the name of the branches of the

splenic artery In human anatomy, the splenic artery or lienal artery is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. It is known for its tortuous path to the s ...

after it passes into the

trabeculae A trabecula (plural trabeculae, from Latin for "small beam") is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has ...

of the

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

, where it branches. When these arteries then reach the

white pulp White pulp is a histological designation for regions of the spleen (named because it appears whiter than the surrounding red pulp on gross section), that encompasses approximately 25% of splenic tissue. White pulp consists entirely of lymphoid ti ...

, and become covered with

periarteriolar lymphoid sheaths Periarteriolar lymphoid sheaths (or periarterial lymphatic sheaths, or PALS) are a portion of the white pulp of the spleen. They are populated largely by T cells and surround central arteries within the spleen; the PALS T-cells are presented with bl ...

, the name changes again to ''central arteries'' (or ''central arterioles''). Branches of the central arteries are given to the

red pulp The red pulp of the spleen is composed of connective tissue known also as the cords of Billroth and many splenic sinusoids that are engorged with blood, giving it a red color. Its primary function is to filter the blood of antigens, microorgani ...

, and these are called ''penicillar arteries'').

Details

The lienal artery is remarkable for its large size in proportion to the size of the organ, and also for its tortuous course. It divides into six or more branches, which enter the hilum of the spleen and ramify throughout its substance, receiving sheaths from an involution of the external fibrous tissue. Similar sheaths also invest the nerves and veins. Each branch runs in the transverse axis of the organ, from within outward, diminishing in size during its transit, and giving off in its passage smaller branches, some of which pass to the anterior, others to the posterior part. These ultimately leave the trabecular sheaths, and terminate in the proper substance of the spleen in small tufts or pencils of minute arterioles, which open into the interstices of the reticulum formed by the branched

sustentacular cell A sustentacular cell is a type of cell primarily associated with structural support, they can be found in various tissues. * Sustentacular cells of the olfactory epithelium (also called supporting cells) have been shown to be involved in the phag ...

s. Each of the larger branches of the artery supplies chiefly that region of the organ in which the branch ramifies, having no anastomosis with the majority of the other branches. The arterioles, supported by the minute trabeculae, traverse the pulp in all directions in bundles (penicilli) of straight vessels. Their trabecular sheaths gradually undergo a transformation, become much thickened, and converted into adenoid tissue; the bundles of connective tissue becoming looser and their fibrils more delicate, and containing in their interstices an abundance of lymph corpuscles. The altered coat of the arterioles, consisting of adenoid tissue, presents here and there thickenings of a spheroidal shape, the

. The arterioles end by opening freely into the splenic pulp; their walls become much attenuated, they lose their tubular character, and the endothelial cells become altered, presenting a branched appearance, and acquiring processes which are directly connected with the processes of the reticular cells of the pulp. In this manner the vessels end, and the blood flowing through them finds its way into the interstices of the reticulated tissue of the splenic pulp.

References

External links

*
Slide at tufts.edu
Arteries {{Portal bar, Anatomy