Inferior ramus of the ischium
Encyclopedia
The Inferior Ramus of the ischium (ascending ramus) 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.
The outer surface is uneven for the origin of the obturator externus and some of the fibers of the adductor magnus; its inner surface forms part of the anterior wall of the pelvis.
Its medial border is thick, rough, slightly everted, forms part of the outlet of the pelvis, and presents two ridges and an intervening space.
The ridges are continuous with similar ones on the inferior ramus of the pubis: to the outer is attached the deep layer of the superficial perineal fascia (fascia of Colles), and to the inner the inferior fascia of the urogenital diaphragm.
If these two ridges be traced downward, they will be found to join with each other just behind the point of origin of the transversus perinæi; here the two layers of fascia are continuous behind the posterior border of the muscle.
To the intervening space, just in front of the point of junction of the ridges, the transversus perinæi is attached, and in front of this a portion of the crus penis vel clitoridis and the ischiocavernosus.
Its lateral border is thin and sharp, and forms part of the medial margin of the obturator foramen
.
Superior ramus
Superior ramus can refer to:* Superior ramus of the ischium* Superior pubic ramus...
, and joins the inferior ramus of the pubis
Pubis (bone)
In vertebrates, the pubic bone is the ventral and anterior of the three principal bones composing either half of the pelvis.It is covered by a layer of fat, which is covered by the mons pubis....
—the junction being indicated in the adult by a raised line.
The outer surface is uneven for the origin of the obturator externus and some of the fibers of the adductor magnus; its inner surface forms part of the anterior wall of the pelvis.
Its medial border is thick, rough, slightly everted, forms part of the outlet of the pelvis, and presents two ridges and an intervening space.
The ridges are continuous with similar ones on the inferior ramus of the pubis: to the outer is attached the deep layer of the superficial perineal fascia (fascia of Colles), and to the inner the inferior fascia of the urogenital diaphragm.
If these two ridges be traced downward, they will be found to join with each other just behind the point of origin of the transversus perinæi; here the two layers of fascia are continuous behind the posterior border of the muscle.
To the intervening space, just in front of the point of junction of the ridges, the transversus perinæi is attached, and in front of this a portion of the crus penis vel clitoridis and the ischiocavernosus.
Its lateral border is thin and sharp, and forms part of the medial margin 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 :...
.