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a plane with more or less definite boundaries; called also regio. adj., adj re´gional.
abdominal r's the areas into which the anterior surface of the abdomen is divided, including the epigastric, hypochondriac (right and left), iliac (right and left), lumbar (right and left), hypogastric, and umbilical.See illustration.
AN region the area of the heart where the atrial fibers merge with the atrioventricular node.
epigastric region the abdominal region that is superior and central in location, above the umbilical region and between the two hypochondriac regions.
facial region that comprising the various anatomical regions of the face, divided into buccal (side of oral cavity), infraorbital (below eye), mental (chin), nasal (nose), oral (lips), orbital (eye), parotid (angle of jaw), and zygomatic (cheek bone) regions.
H region the area of the bundle of His from its connection with the atrioventricular node to its branching portion.
homology r's looped structures, comprising approximately 100 amino acid residues and fastened by disulfide bonds, that show similarities in primary structure from one region to another. They represent the building blocks or units of immunoglobulin molecules.
hypochondriac region either of the abdominal regions that are in superior lateral locations, one on the left (left hypochondriac region) and one on the right (right hypochondriac region) of the epigastric region; called also hypochondrium.
hypogastric region suprapubic region.
I region that part of the major histocompatibility complex where immune response genes are present.
iliac region inguen.
inframammary region the part of the pectoral region inferior to the breast, bordered inferiorly by the hypochondriac region of the abdomen.
inguinal region inguen.
lateral region either of the abdominal regions that are in central lateral locations, one to the left (left lateral region) and one to the right (right lateral region) of the umbilical region; called also flank and lumbar region.
lateral pectoral region the most lateral part of the pectoral region, bounded laterally by the axillary region.
1. the region of the back lying lateral to the lumbar vertebrae. See also loin.
2. lateral region.
N region [nodal region] the region of the atrioventricular node consisting of the body of the node.
NH region [nodal-His region] the area where the atrioventricular node becomes the bundle of His.
pectoral region the aspect of the chest overlying the pectoralis major muscle, subdivided into the lateral pectoral, mammary, and inframammary regions.
pelvic region suprapubic region.
perineal region the region underlying the pelvic outlet, subdivided into the anal and urogenital regions.
precordial region the part of the anterior surface of the body covering the heart and the pit of the stomach.
presternal region the region of the thorax overlying the sternum, bounded laterally by the pectoral regions.
pubic region suprapubic region.
suprapubic region the abdominal region that is inferior and central in location, below the umbilical region and between the two iliac(inguinal) regions; called also hypogastric or pelvic region.
umbilical region the abdominal region that is most central in location, surrounding the umbilicus; it is bounded laterally by the two lateral or lumbar regions, superiorly by the epigastric region, and inferiorly by the suprapubic or hypogastric region.
urogenital region the part of the perineal region that surrounds the external genital organs and the urethral orifice,