Inferior pubic ramus
Encyclopedia
The inferior pubic ramus is a part of the pelvis and is thin and flat. It passes laterally and downward from the medial end of the superior ramus
; it becomes narrower as it descends and joins with the inferior ramus of the ischium
below the obturator foramen
.
along its medial border, a portion of the Obturator externus where it enters into the formation of the obturator foramen
, and between these two, the Adductores brevis and magnus, the former being the more medial.
The posterior surface is smooth, and gives origin to the Obturator internus, and, close to the medial margin, to the Constrictor urethrae.
The ridges extend downward, and are continuous with similar ridges on the inferior ramus of the ischium
;
The lateral border is thin and sharp, forms part of the circumference of the obturator foramen
, and gives attachment to the obturator membrane
.
Superior pubic ramus
The superior pubic ramus is a part of the pubic bone which forms a portion of the obturator foramen.It extends from the body to the median plane where it articulates with its fellow of the opposite side...
; it becomes narrower as it descends and joins with the inferior ramus of the ischium
Inferior ramus of the ischium
The Inferior Ramus of the ischium is the thin, flattened part of the ischium, which ascends from the superior ramus, and joins the inferior ramus of the pubis—the junction being indicated in the adult by a raised line....
below the obturator foramen
Obturator foramen
The obturator foramen is the hole created by the ischium and pubis bones of the pelvis through which nerves and muscles pass.- General structure :...
.
Surfaces
Its anterior surface is rough, for the origin of muscles—the GracilisGracilis muscle
The gracilis is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above, narrow and tapering below.-Origin and insertion:...
along its medial border, a portion of the Obturator externus where it enters into the formation of the obturator foramen
Obturator foramen
The obturator foramen is the hole created by the ischium and pubis bones of the pelvis through which nerves and muscles pass.- General structure :...
, and between these two, the Adductores brevis and magnus, the former being the more medial.
The posterior surface is smooth, and gives origin to the Obturator internus, and, close to the medial margin, to the Constrictor urethrae.
Borders
The medial border is thick, rough, and everted, especially in females. It presents two ridges, separated by an intervening space.The ridges extend downward, and are continuous with similar ridges on the inferior ramus of the ischium
Inferior ramus of the ischium
The Inferior Ramus of the ischium is the thin, flattened part of the ischium, which ascends from the superior ramus, and joins the inferior ramus of the pubis—the junction being indicated in the adult by a raised line....
;
- to the external is attached the fascia of CollesFascia of CollesThe deep layer of superficial fascia is thin, aponeurotic in structure, and of considerable strength, serving to bind down the muscles of the root of the penis.It separates the skin from the superficial perineal pouch.-Relations:...
. - to the internal the inferior fascia of the urogenital diaphragmUrogenital diaphragmOlder texts have asserted the existence of an urogenital diaphragm, also called the triangular ligament, which was described as a layer of the pelvis that separates the deep perineal sac from the upper pelvis, lying between the inferior fascia of the urogenital diaphragm and superior fascia of the...
.
The lateral border is thin and sharp, forms part of the circumference of the obturator foramen
Obturator foramen
The obturator foramen is the hole created by the ischium and pubis bones of the pelvis through which nerves and muscles pass.- General structure :...
, and gives attachment to the obturator membrane
Obturator membrane
The obturator membrane is a thin fibrous sheet, which almost completely closes the obturator foramen.Its fibers are arranged in interlacing bundles mainly transverse in direction; the uppermost bundle is attached to the obturator tubercles and completes the obturator canal for the passage of the...
.