What Is the Pelvis Definition Structure Functions and Diagram
The pelvis is also known as the bony pelvis or pelvic girdle. It is a complex bone which is basin-shaped that connects the trunk and the legs. It provides balance and support to the trunk and also supports the intestine, intestinal organ and internals sex organs. In simple words, the pelvis is the part between the abdomen and thigh bone (femur). If we speak about pelvis anatomy, the pelvis is made of three bones ilium (which accounts for the width of the hips), The ischium (behind and below on which weight falls during sitting), and pubis in the front. All these unite to form triangular structures in the acetabulum. The cup-shaped socket formed by the hip joint helps to attach femur the thigh bones.
Pelvis Diagram
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Parts of the Pelvis
Let us discuss some of the important parts of the pelvis are :
Sacrum: It is also known as sacral vertebra. It is a shield-shaped bone located at the base of the vertebrae. Sacrum imparts strength and stability to the pelvis and also forms the posterior wall.
Tail bone: It is also known as the coccyx. The tail bone is the small triangular shape which hardly looks like a tail. The coccyx is the last segment of the vertebral column and it also provides support for weight and helps in the movement.
Hip bones: It consists of three parts- Pubis, ilium, and ischium. All these three bones are separated by triradiate cartilage before puberty. These three bones start to fuse with each other at the age of 15-16.
Structure of Female Pelvis:
There are some of the structural differences between male and female pelvis anatomy. The female pelvis is designed in such a way that it provides enough space for the baby to develop. And pass through the birth canal of the female pelvis. Due to this reason, the female pelvis is generally broader and wider than the male pelvis. The majority of women have gynaecoid pelvis and male have an android pelvis. Rather than bony differences, the sacrotuberous and sacrospinous ligaments can stretch the size under the influence of progesterone.
Types of Pelvis
Pelvis shape widely varies in females. The shape of the pelvis decides whether a person can give birth vaginally or not. The four general types of pelvis are:
Gynecoid: It is the most common pelvis shape found in females and it favours for the vaginal birth. Other shapes like android and platypelloid face more difficulty in vaginal birth. It is also known as the genuine female pelvis.
Android: android pelvis have heart-shaped brim with narrow shape in the front. This type of pelvis is found in tall women with narrow hips and also in African women.
Anthropoid: Anthropoid pelvis has an oval-shaped brim with a slightly narrow pelvic cavity. In this the outlet is large but some of the diameters are reduced.
Platypelloid: The platypelloid pelvis has a kidney-shaped brim and it may be tapered in diameter from front to back. In this, there's only a problem for the baby while entering the pelvis.
Functions of the Pelvis
Pelvis plays a number of roles in the human body. Some of the important functions are discussed below-
To transfer the weight from the upper skeleton to the lower component of the skeleton mainly during movement.
It helps to join the number of muscles and ligaments used during locomotion.
It protects the abdominopelvic and pelvic viscera.
FAQs on Pelvis Structure and Functions in Human Body
1. What is the pelvis in human anatomy?
The pelvis is a bony ring-like structure at the base of the spine that connects the trunk to the lower limbs and supports pelvic organs. It is formed by:
- Two hip bones (coxal bones)
- The sacrum
- The coccyx
2. What bones make up the pelvis?
The human pelvis is made up of two hip bones, the sacrum, and the coccyx. Each hip bone is formed by the fusion of three bones:
- Ilium
- Ischium
- Pubis
3. What is the function of the pelvis?
The main function of the pelvis is to support body weight and protect pelvic organs. Its key functions include:
- Transmitting body weight from the spine to the lower limbs
- Protecting organs such as the urinary bladder, rectum, and reproductive organs
- Providing attachment sites for major muscles of the lower limb and trunk
- Forming the birth canal in females
4. What is the difference between the male and female pelvis?
The female pelvis is wider and shallower than the male pelvis to facilitate childbirth. Key differences include:
- Female pelvis has a wider pelvic inlet and outlet
- Male pelvis is narrower and heavier
- The subpubic angle is larger in females (usually >80°)
- The female sacrum is shorter and less curved
5. What is the pelvic girdle?
The pelvic girdle is the part of the skeleton that attaches the lower limbs to the axial skeleton. It consists of:
- Two hip (coxal) bones
6. What is the acetabulum?
The acetabulum is a cup-shaped socket in the hip bone that forms the hip joint by articulating with the head of the femur. It is formed by the fusion of the:
- Ilium
- Ischium
- Pubis
7. What organs are protected by the pelvis?
The pelvis protects major organs of the urinary, digestive, and reproductive systems. These include:
- Urinary bladder
- Part of the large intestine (rectum)
- Uterus and ovaries in females
- Prostate gland in males
8. What is the pelvic cavity?
The pelvic cavity is the space enclosed by the pelvic bones that contains pelvic organs. It is located below the abdominal cavity and is divided into:
- The false (greater) pelvis, which supports abdominal organs
- The true (lesser) pelvis, which encloses the pelvic organs
9. How does the pelvis support movement?
The pelvis supports movement by transferring body weight to the lower limbs and serving as a muscle attachment site. It enables locomotion through:
- Articulation at the hip joints
- Attachment of strong muscles such as the gluteal muscles
- Stabilization via the sacroiliac joints
10. Why is the female pelvis important in childbirth?
The female pelvis is important in childbirth because it forms the bony birth canal through which the baby passes during delivery. Important features include:
- A wider pelvic inlet and outlet
- A larger subpubic angle
- A broader and less curved sacrum
