Composition
The sacral plexus is formed by:
- the lumbosacral trunk
- the anterior division of the first sacral nerve
- portions of the anterior divisions of the second and third sacral nerves
The nerves forming the sacral plexus converge toward the lower part of the greater sciatic foramen, and unite to form a flattened band, from the anterior and posterior surfaces of which several branches arise.
The band itself is continued as the sciatic nerve, which splits on the back of the thigh into the tibial nerve and common fibular nerve; these two nerves sometimes arise separately from the plexus, and in all cases their independence can be shown by dissection.
Often, the sacral plexus and the lumbar plexus are considered to be one large nerve plexus, the lumbosacral plexus. The lumbosacral trunk connects the two plexuses.
Read more about this topic: Sacral Plexus
Famous quotes containing the word composition:
“There is singularly nothing that makes a difference a difference in beginning and in the middle and in ending except that each generation has something different at which they are all looking. By this I mean so simply that anybody knows it that composition is the difference which makes each and all of them then different from other generations and this is what makes everything different otherwise they are all alike and everybody knows it because everybody says it.”
—Gertrude Stein (1874–1946)
“Vices enter into the composition of virtues as poisons into the composition of certain medicines. Prudence and common sense mix them together, and make excellent use of them against the misfortunes that attend human life.”
—François, Duc De La Rochefoucauld (1613–1680)
“I live in the angle of a leaden wall, into whose composition was poured a little alloy of bell-metal. Often, in the repose of my mid-day, there reaches my ears a confused tintinnabulum from without. It is the noise of my contemporaries.”
—Henry David Thoreau (1817–1862)