It continues its course in a neurovascular bundle through the posterior leg compartment and passes through the tarsal tunnel. More specifically, the tibial nerve passes through the center of the popliteal fossa and runs below the tendinous arch of the soleus muscle. The tibial nerve continues the course of the sciatic nerve and descends down through the posterior aspect of the leg as far as the heel of the foot. On its course through the posterior thigh, the sciatic nerve gives off several small motor muscular branches that innervate the several muscles of the thigh.Īt the apex of the popliteal fossa, the sciatic nerve terminates by dividing into two terminal branches: Try out nervous system quizzes and diagrams and soon you will see there’s nothing to be afraid of! ![]() Learning about the nervous system can be a real challenge. It runs between the long head of the biceps femoris muscle and the adductor magnus muscle, and laterally to the semitendinosus and semimembranosus muscles. The sciatic nerve then continues its course through the posterior thigh. It passes inferior to the piriformis muscle, accompanied by the posterior femoral cutaneous nerve, pudendal nerve, internal pudendal artery and vein, inferior gluteal nerve, inferior gluteal artery and vein. The sciatic nerve then descends posteriorly and leaves the pelvis through the greater sciatic foramen. The anterior branches of these five spinal nerves meet and converge in the posterior pelvic region to form a single large nerve. It is formed from both anterior and posterior divisions of the anterior (ventral) rami of spinal nerves L4 through S3. The sciatic nerve is a terminal branch of the sacral plexus. Sensory: Posterior thigh, lateral and posterior leg, dorsum and sole of the foot. Motor: Muscles of the posterior thigh, ischial portion of adductor magnus, muscles of the posterior, anterior and lateral compartments of the leg, foot muscles. Muscular branches of sciatic nerve, tibial nerve, common fibular (peroneal) nerve This article will discuss the anatomy and function of the sciatic nerve. The main function of the sciatic nerve is to provide sensory and motor supply to the skin and muscles of the thigh, leg and foot. Before entering the popliteal fossa, the nerve terminates by splitting into two large terminal branches: the tibial nerve and common fibular (peroneal) nerve. It descends through the posterior aspect of the thigh. The sciatic nerve arises in the lumbosacral region. It contains fibers from both the posterior and anterior divisions of these spinal nerves. ![]() ![]() It originates from the anterior rami of the lower lumbar (L4-L5) and upper sacral spinal nerves (S1, S2, S3). Atlas of Human Anatomy.The sciatic nerve is the largest nerve in the human body and is derived from the sacral plexus. Tunica vaginalis : serous whose parietal layer represents the deepest layer of the scrotum, while the visceral layer involves the testis, epididymis and beginning of the vas deferens. Internal spermatic fascia: conjunctival lamina that derives from the transversalis fascia. Together, these muscle fibers constitute the cremaster muscle and derive from the fibers of the internal oblique muscle of the abdomen. Subcutaneous tissue : consists of loose connective tissue.Įxternal spermatic fascia: it is a conjunctive layer that comes from the two fasciae that wrap the external oblique muscle of the abdomen, which descends from the superficial inguinal annulus to enter the constitution of the scrotum.Ĭremasteric fascia : this plane is represented by a thin conjunctival lamina that holds numerous bundles of striated muscle fibers in a vertical direction. In the midline we find the raphe of the scrotum.ĭartos tunic: the dartos tunic is a true cutaneous muscle, formed by smooth muscle fibers. The scrotum is made up of different tissue layers that are stratified from the periphery to the depth, in the following seven planes.Ĭutis : is the thin, wrinkled skin that has transverse folds and sparse hairs. Superficially, this septum corresponds to a very evident cutaneous raphe (median rough line). The scrotum is a musculocutaneous pouch that contains the testes, epididymis and the first portion of the vas deferens.Įach set of these organs (right and left) occupies a completely separate compartment, since the scrotum is subdivided into two stores by a median sagittal partition called the scrotal septum.
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