Posterior Division Of The Sacral Plexus

Tensor Fascia Lata Nerve

The posterior division of the sacral plexus consists of ventral rami from L4-S3, which form a network and give rise to the following six nerves Perforating cutaneous nerve (S2-S3). Pierces the sacro-tuberous ligament and travels to the inferior edge of the glu-teus maximus muscle, providing sensory innervation to the skin over the inferior aspect of the gluteus maximus (inferior gluteal fold). Nerve to piriformis muscle (S1-S2). Travels directly from the plexus to the piriformis muscle,...

Innervation Of The Kidneys And The Proximal Part Of The Ureters

Ureter Nerves

The autonomic innervation of the kidneys and proximal ureters is as follows Sympathetic innervation. Preganglionic neurons course through the lesser, least, and lumbar splanchnic nerves.They synapse in the aorticorenal and superior mesenteric ganglia, where postganglionic neurons course in a renal plexus to the kidneys. Parasympathetic innervation. Preganglionic parasympa-thetic neurons originate in the brainstem and course in the vagus nerve to enter the abdomen. The vagus nerve branches to...

Superficial Perineal Space

Perineal Membrane

The superficial perineal space (pouch) is the region inferior to the urogenital diaphragm. It is enclosed by the superficial perineal (Colles') fascia. The superficial perineal space contains (Figure 13-1A-D) Deep (Buck's) fascia of the penis. Continuous with the external spermatic fascia and deep perineal fascia. The deep dorsal vein of the penis is inside this fascial layer. CRURA OF THE PENIS Each crus of the penis is composed of erectile tissue that is continuous with the paired corpus...

Inferior Hypogastric Plexus

Hypogastric

The inferior hypogastric plexus is formed by the union of nerves from the superior hypogastric plexus, sacral splanchnic nerves, and pelvic splanchnic nerves (Figure 12-4A). The inferior hypogastric plexus is located diffusely around the lateral walls of the rectum, bladder, and vagina. The plexus contains ganglia in which both sympathetic and parasympathetic pre-ganglionic fibers synapse. Therefore, the inferior hypogastric plexus consists of preganglionic and postganglionic sympathetic and...

Sternocleidomastoid And Trapezius Muscles

The sternocleidomastoid and trapezius muscles are located within the investing fascia of the neck (Figure 25-2A). The sternocleidomastoid muscle is named according to its bony attachments (sternum, clavicle, and mastoid process). The sternocleidomastoid muscle creates the borders for both the anterior and the posterior triangles of the neck, and is innervated by the spinal accessory nerve (CN XI). This muscle flexes the neck, pulls the chin upward, and assists in elevating the rib cage during...

Boundaries And Divisions Of The Anterior Triangle

Submandibular Lymph Nodes

The borders, or boundaries, of the anterior triangle are as follows (Figure 26-2A) Anteriorly. The midline down the neck. Posteriorly. The sternocleidomastoid muscle. Superiorly. The lower border of the mandible. The anterior triangle is subdivided by three structures the omohyoid muscle, the hyoid bone, and the digastric muscle into submandibular, carotid, submental, and muscular triangles (Figure 26-2B). The submental and muscular triangles have little clinical value and, therefore, will not...

Muscles Of The Posterior Compartment Of The Thigh

Hamstrings Muscles Posterior Thigh

The muscles in the posterior compartment of the thigh are primarily extensors of the hip or flexors of the knee because of their posterior orientation. The tibial nerve (L4-S3) innervates the muscles in the posterior compartment of the thigh, with the exception of the short head of the biceps femoris muscles (common fibular nerve). Muscles in this compartment do not receive all the innervation levels from the tibial nerve rather, they receive innervation from the spinal nerve level between L5...