inferior posterior serratus muscle inferior posterior ser·ra·tus muscle (sə-rā’təs)
A muscle with origin from the two lower thoracic and two upper lumbar vertebrae, with insertion into the last four ribs, whose action draws the lower ribs backward and downward, with nerve supply from the ninth to the twelfth intercostal nerves.
- Inferior pulmonary vein
inferior pulmonary vein n.
- Inferior rectal nerve
inferior rectal nerve n. Any of several branches of the pudendal nerve that pass to the external sphincter muscle of the anus and that supply the skin of the anal region.
- Inferior rectal vein
inferior rectal vein n. Any of the veins that pass to the internal pudendal vein from the venous plexus around the anal canal.
- Inferior rectus muscle
inferior rectus muscle n. A muscle with origin from the inferior part of the tendinous ring, with insertion into the sclera of the eye, with nerve supply from the oculomotor nerve, and whose action directs the pupil downward and medialward.