has part has part characteristic of inheres in has modifier Abnormal retinal arterial/arteriolar morphology Retinal arterial tortuosity The presence of an increased number of twists and turns of the retinal artery. HP:0000631 SNOMEDCT_US:247123003 Retinal artery tortuousity Normal retinal blood vessels are straight or gently curved. In some diseases, the blood vessels become tortuous, i.e. they become dilated and take on a serpentine path. The dilation is caused by radial stretching of the blood vessel and the serpentine path occurs because of longitudinal stretching. The tortuosity may be focal, occurring only in a small region of retinal blood vessels, or it may involve the entire retinal vascular tree. UMLS:C0423401 Arterial tortuosity Retinal vascular tortuosity abnormal retina