Arteriole

A small branch of an artery (a vessel that carries blood high in oxygen away from the heart to the body) leading to a capillary. The oxygenated hemoglobin (oxyhemoglobin) makes the blood in arteries and arterioles look bright red.

* * *

A minute artery with a tunica media comprising only one or two layers of smooth muscle cells; a terminal artery continuous with the capillary network. SYN: arteriola [TA].

- afferent glomerular a. [TA] a branch of an interlobular artery of the kidney that conveys blood to the glomerulus. SYN: arteriola glomerularis afferens [TA], afferent vessel (2), vas afferens.

- capillary a. a minute artery that terminates in a capillary.

- efferent glomerular a. [TA] the vessel that carries blood from the glomerular capillary network to the capillary bed of the proximal convoluted tubule; collectively, these vessels constitute the renal portal system. SYN: arteriola glomerularis efferens [TA], efferent vessel, vas efferens (2).

- inferior macular a. [TA] origin, central artery of retina; distribution, inferior part of macula. SYN: arteriola macularis inferior [TA].

- inferior nasal a. of retina [TA] the branch of the central artery of the retina that supplies the lower medial, or nasal, part of the retina. SYN: arteriola nasalis retinae inferior [TA].

- inferior temporal retinal a. [TA] the branch of the central artery of the retina that passes laterally below the macula to supply the lower lateral or temporal part of the retina. SYN: arteriola temporalis retinae inferior [TA].

- medial a. of retina SYN: middle macular a..

- middle macular a. [TA] an a. supplying the part of the retina between the optic disk and the macula. SYN: arteriola medialis retinae [TA], medial a. of retina.

- superior macular a. [TA] origin, central artery of retina; distribution, upper part of macula. SYN: arteriola macularis superior [TA].

- superior nasal retinal a. [TA] the branch of the central artery of the retina that passes to the upper medial, or nasal, part of the retina. SYN: arteriola nasalis retinae superior [TA].

- superior temporal retinal a. [TA] the branch of the central artery of the retina that passes laterally above the macula to supply the upper lateral or temporal part of the retina. SYN: arteriola temporalis retinae superior [TA].

* * *

ar·te·ri·ole är-'tir-ē-.ōl n any of the small terminal twigs of an artery that ends in capillaries

ar·te·ri·o·lar -.tir-ē-'ō-.lär, -lər adj

* * *

n.

a small branch of an artery, leading into many smaller vessels - the capillary. By their constriction and dilation, under the regulation of the sympathetic nervous system, arterioles are the principal controllers of blood flow and pressure.

* * *

ar·te·ri·ole (ahr-tērґe-ōl) [L. arteriola] arteriola. arteriolar adj