Abdominal Reflexes

Abdominal Reflexes (Rosenbach), are elicited by stroking irritation of the abdominal wall. On each side, three abdominal reflexes are distinguished: 1) the upper abdominal, or epigastric reflex, is elicited by stroking irritation conducted along the upper part of the abdominal wall in an oblique direction, parallel to the edge of the costal arch; 2) the middle abdominal, or mesogastric reflex, by stroking irritation conducted at the level of the navel horizontally; 3) the lower abdominal, or hypogastric reflex, by stroking irritation conducted along the lower part of the abdominal wall parallel to the inguinal fold. Bekhterev also distinguishes a fourth abdominal reflex, the so-called suprapubic, elicited by stroking irritation of the inner surface of the thigh. Effect of abdominal reflexes: contraction of the rectus abdominis muscles, external and internal oblique muscles, transverse abdominal muscle (contraction of the abdominal wall at the corresponding level). The upper reflex corresponds to the VI-VII thoracic segments, the middle to VIII-IX, and the lower to X-XI-XII. In normal conditions, the reflexes are characterized by great constancy, unless the abdominal wall appears excessively flaccid. They disappear with lesions of the aforementioned segments of the spinal cord, as well as the anterior or posterior roots or the corresponding peripheral nerves. They also disappear with lesions of the pyramidal pathways. This leads many to assume that the reflex arc of abdominal and other skin reflexes is closed in the cerebral cortex.