| Pubic arch | |
|---|---|
 Female pelvis (pubic arch labeled at bottom center) | |
 Male pelvis (pubic arch labeled at bottom center) | |
| Details | |
| Identifiers | |
| Latin | arcus pubicus |
| TA98 | A02.5.02.003 |
| TA2 | 1284 |
| FMA | 16951 |
| Anatomical terms of bone | |
The pubic arch, also referred to as the ischiopubic arch, is part of the pelvis. It is formed by the convergence of the inferior rami of the ischium and pubis on either side, below the pubic symphysis. The angle at which they converge is known as the subpubic angle. [1]
The pubic arch is one of three notches (the one in front) that separate the eminences of the lower circumference of the true pelvis.[ citation needed ]
The subpubic angle (or pubic angle) is the angle in the human body as the apex of the pubic arch, formed by the convergence of the inferior rami of the ischium and pubis on either side. The subpubic angle is important in forensic anthropology, in determining the sex of someone from skeletal remains. A subpubic angle of 50–82 degrees indicates a male; an angle of 90 degrees indicates a female. [2] Other sources operate with 50–60 degrees for males and 70–90 degrees in females. [1] Women have wider hips, and thus a greater subpubic angle, in order to allow for child birth.
The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis.
The acetabulum also called the cotyloid cavity, is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.
The pubic symphysis is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attaches to the pubic symphysis. In females, the pubic symphysis is close to the clitoris. In most adults it can be moved roughly 2 mm and with 1 degree rotation. This increases for women at the time of childbirth.
The ischiocavernosus muscle is a muscle just below the surface of the perineum, present in both men and women.
The bulbospongiosus muscle is one of the superficial muscles of the perineum. It has a slightly different origin, insertion and function in males and females. In males, it covers the bulb of the penis. In females, it covers the vestibular bulb.
The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, and the rim of the pubis.
In vertebrate anatomy, hip refers to either an anatomical region or a joint.
The external obturator muscle, obturator externus muscle is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis.
The clitoral crura are two erectile tissue structures, which together form a V-shape. Crus is a Latin word that means "leg". Each "leg" of the V converges on the clitoral body. At each divergent point is a corpus cavernosum of clitoris. The crura are attached to the pubic arch, and are adjacent to the vestibular bulbs. The crura flank the urethra, urethral sponge, and vagina and extend back toward the pubis. Each clitoral crus connects to the rami of the pubis and the ischium.
The obturator foramen is the large, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium. It is mostly closed by the obturator membrane except for a small opening - the obturator canal - through which the obturator nerve and vessels pass.
The ischium forms the lower and back region of the hip bone.
In vertebrates, the pubis or pubic bone forms the lower and anterior part of each side of the hip bone. The pubis is the most forward-facing of the three bones that make up the hip bone. The left and right pubic bones are each made up of three sections, a superior ramus, inferior ramus, and a body.
The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet. Its lower boundary is the pelvic floor.
The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term "inferior fascia of urogenital diaphragm", used in older texts, is considered equivalent to the perineal membrane.
The pelvic fasciae are the fascia of the pelvis and can be divided into:
The ischiopubic ramus is a compound structure consisting of the following two structures:
The lower circumference of the lesser pelvis is very irregular; the space enclosed by it is named the inferior aperture or pelvic outlet. It is an important component of pelvimetry.
The hip bone is a large flat bone, constricted in the center and expanded above and below. In some vertebrates it is composed of three parts: the ilium, ischium, and the pubis.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
The vaginal support structures are those muscles, bones, ligaments, tendons, membranes and fascia, of the pelvic floor that maintain the position of the vagina within the pelvic cavity and allow the normal functioning of the vagina and other reproductive structures in the female. Defects or injuries to these support structures in the pelvic floor leads to pelvic organ prolapse. Anatomical and congenital variations of vaginal support structures can predispose a woman to further dysfunction and prolapse later in life. The urethra is part of the anterior wall of the vagina and damage to the support structures there can lead to incontinence and urinary retention.
This article incorporates text in the public domain from page 240 of the 20th edition of Gray's Anatomy (1918)
