Anatomy
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is the Pelvis?

H. Colledge
H. Colledge

The word pelvis is generally used to refer to that part of the body just below the abdomen, which is the area where the trunk joins the legs. More specifically, the term refers to the part of the skeleton, also known as the bony pelvis or pelvic girdle, which encloses and supports that area of the body. The word means "basin" in Latin, which is what the shape of the bony structure resembles. Another use of the term refers to structures found in the kidneys, which have funnel-shaped renal pelvises formed from the top of the urine collecting tubes, or ureters, that carry urine to the bladder.

Four bones make up the bony pelvis, with two hip bones, called the inominate bones, forming the front and sides, while two bones at the bottom of the spine, known as the sacrum and coccyx, complete the rear wall. Around the inside of the pelvic bones is a ridge called the iliopectineal line which runs around the central opening to meet a joint at the front, known as the symphysis pubis. This ridge represents the pelvic brim, also called the inlet. While the area above the inlet is known as the false pelvis, the region below is referred to as the true pelvis.

Motorcycle and car accidents commonly cause pelvis fractures.
Motorcycle and car accidents commonly cause pelvis fractures.

The false pelvis flares out and supports the contents of the abdomen, and is continuous with the abdominal cavity. By contrast, the true one has more of a bowl shape and it encloses the reproductive organs, the lower gut and parts of the urinary tract. It has an inlet formed by the pelvic brim, and an outlet made from the structures at the bottom of the pelvic bone, which include the end of the spine, the arched lower edge of the symphysis pubis, and the lower parts of the hip bones. What is known as the pelvic cavity lies between the inlet and the outlet.

An X-ray of the pelvis.
An X-ray of the pelvis.

In women, the inlet, the pelvic cavity and the outlet form the canal through which a baby passes. Pelvises vary in shape between men and women, with female ones being adapted to cope with giving birth. For this reason, pelvises are shallower in women, with smoother bony surfaces and the pelvic cavity and outlet are roomier than in men.

Fractures of the pelvic region can occur, usually due to a severe, direct blow or crushing injury, or occasionally the thighbone may be pushed right through the hip socket as the result of a fall. Motor vehicle or motorcycle accidents are common causes of fractures. If the true pelvis is fractured there is usually also damage to the organs contained inside. Treatment of pelvic fractures involves fixing the fragments together with metal screws, wires and plates to allow the bones to heal.

Discussion Comments

anon310658

Does the pelvis have anything to do with the nervous system besides for the fact that the spinal cord ends there?

rosoph

Having a fractured pelvis sounds like it would be extremely painful! How would you sit down with this kind of injury? I'll bet people that have this happen to them are required to lay in bed for a very long time while it heals.

Could this type of injury result in someone never being able to walk again?

geronimo8

It always amazes me that a baby can pass through the bones of the pelvis! How is this possible? Do the bones actually move when giving birth? And if so, do they go back afterward?

The workings of the body are absolutely amazing!

upnorth31

My mom was in a horrible car accident before I was born, and she broke her pelvis. I'm not sure if it was the true pelvis or the false pelvis, but I don't think it was fixed with screw or plates or anything like that.

She did say that it was incredibly painful.

If this is the area that a baby passes through, I imagine that breaking it could result in trouble giving birth. Maybe this is why I was born by cesarean section.

Post your comments
Login:
Forgot password?
Register:
    • Motorcycle and car accidents commonly cause pelvis fractures.
      By: oscar williams
      Motorcycle and car accidents commonly cause pelvis fractures.
    • An X-ray of the pelvis.
      By: Allen Penton
      An X-ray of the pelvis.
    • The pelvis is comprised of three bones: the ilium, the ischium, and the pubis.
      By: James Steidl
      The pelvis is comprised of three bones: the ilium, the ischium, and the pubis.
    • The shape of the pelvis varies in size between women and men.
      By: WavebreakmediaMicro
      The shape of the pelvis varies in size between women and men.
    • Pelvises are shallower in women to help cope with giving birth.
      By: olly
      Pelvises are shallower in women to help cope with giving birth.