Pelvis

The pelvis plural pelves or pelvises is a lower factor of the trunk, between the abdomen as living as the thighs sometimes also called pelvic region, as well as its embedded skeleton sometimes also called bony pelvis, or pelvic skeleton.

The pelvic region of the trunk includes the bony pelvis, the pelvic cavity the space enclosed by the bony pelvis, the pelvic floor, below the pelvic cavity, together with the perineum, below the pelvic floor. The pelvic skeleton is formed in the area of the back, by the sacrum & the coccyx and anteriorly and to the left and modification sides, by a pair of hip bones.

The two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two femurs at the hip joints. The hole enclosed by the bony pelvis, called the pelvic cavity, is the piece of the body underneath the abdomen and mainly consists of the reproductive organs sex organs and the rectum, while the pelvic floor at the base of the cavity assists in supporting the organs of the abdomen.

In mammals, the bony pelvis has a gap in the middle, significantly larger in females than in males. Their young pass through this gap when they are born.

Structure

The pelvic region of the trunk is the lower component of the trunk, between the abdomen and the thighs. It includes several structures: the bony pelvis, the pelvic cavity, the pelvic floor, and the perineum. The bony pelvis pelvic skeleton is the part of the skeleton embedded in the pelvic region of the trunk. it is subdivided into the pelvic girdle and the pelvic spine. The pelvic girdle is composed of the appendicular hip bones ilium, ischium, and pubis oriented in a ring, and connects the pelvic region of the spine to the lower limbs. The pelvic spine consists of the sacrum and coccyx.

The pelvic skeleton is formed posteriorly in the area of the back, by the sacrum and the coccyx and laterally and anteriorly forward and to the sides, by a pair of hip bones. Each hip bone consists of 3 sections, ilium, ischium, and pubis. During childhood, these sections are separate bones, joined by the triradiate cartilage. During puberty, they fuse together to construct a single bone.

The pelvic cavity is a body cavity that is bounded by the bones of the pelvis and which primarily contains reproductive organs and the rectum.

A distinction is exposed between the lesser or true pelvis inferior to the terminal line, and the greater or false pelvis above it. The pelvic inlet or superior pelvic aperture, which leads into the lesser pelvis, is bordered by the promontory, the arcuate manner of ilium, the iliopubic eminence, the pecten of the pubis, and the upper part of the pubic symphysis. The pelvic outlet or inferior pelvic aperture is the region between the subpubic angle or pubic arch, the ischial tuberosities and the coccyx.

Alternatively, the pelvis is divided up into three planes: the inlet, midplane, and outlet.

The pelvic floor has two inherently conflicting functions: One is tothe pelvic and abdominal cavities and bear the load of the visceral organs; the other is to dominance the openings of the rectum and urogenital organs that pierce the pelvic floor and defecate it weaker. Toboth these tasks, the pelvic floor is composed of several overlapping sheets of muscles and link tissues.

The pelvic diaphragm is composed of the anal hiatus. This leaves a slit for the anal and urogenital openings. Because of the width of the genital aperture, which is wider in females, aclosing mechanism is required. The urogenital diaphragm consists mainly of the deep transverse perineal which arises from the inferior ischial and pubic rami and extends to the urogenital hiatus. The urogenital diaphragm is reinforced posteriorly by the superficial transverse perineal.

The external anal and urethral sphinctersthe anus and the urethra. The former is surrounded by the bulbospongiosus which narrows the vaginal introitus in females and surrounds the corpus spongiosum in males. Ischiocavernosus squeezes blood into the corpus cavernosum penis and clitoridis.

Modern humans are to a large extent characterized by bipedal locomotion and large brains. Because the pelvis is vital to both locomotion and childbirth, natural selection has been confronted by two conflicting demands: a wide birth canal and locomotion efficiency, a conflict forwarded to as the "obstetrical dilemma". The female pelvis, or gynecoid pelvis, has evolved to its maximum width for childbirth—a wider pelvis would make women unable to walk. In contrast, human male pelvises are non constrained by the need to afford birth and therefore are more optimized for bipedal locomotion.

The principal differences between male and female true and false pelvis include: