Pelvis

Question 1

Bones of the Pelvis

Answer 1

The primary bones of the pelvis include:

1. Ilium: The largest part of the pelvis, contributing to the superior aspect.
2. Ischium: Forms the lower and back part of the pelvis.
3. Pubis: The front portion of the pelvis, which meets at the pubic symphysis.
4. Sacrum: A triangular bone at the base of the spine, formed by the fusion of five vertebrae.
5. Coccyx: Also known as the tailbone, it is formed by the fusion of three to five rudimentary vertebrae.

Question 2

Joints of the Pelvis

Answer 2

The pelvis contains several important joints that allow for movement and stability:

1. Sacroiliac Joints: These are synovial joints between the sacrum and the ilium, allowing for limited movement and providing stability to the pelvis.
2. Pubic Symphysis: A cartilaginous joint that connects the two pubic bones at the front of the pelvis, allowing for slight movement.
3. Lumbosacral Joint: The joint between the last lumbar vertebra and the sacrum, which is a plane type joint that allows for limited movement

Question 3

Muscles of the Pelvis

Answer 3

The pelvic region houses several muscle groups that play crucial roles in movement and stability:

1. Pelvic Floor Muscles: These include the levator ani and coccygeus muscles, which support pelvic organs and contribute to urinary and fecal continence.
2. Gluteal Muscles: The gluteus maximus, medius, and minimus are important for hip movement and stability.
3. Hip Flexors: Including the iliopsoas muscle, which is crucial for flexing the hip joint.
4. Adductor Muscles: These muscles are located on the inner thigh and are responsible for adducting the hip.

Question 4

Ligaments of the Pelvis

Answer 4

Several ligaments provide stability to the pelvic structure:

1. Sacroiliac Ligaments: These include the anterior and posterior sacroiliac ligaments, which stabilize the sacroiliac joints.
2. Pubic Ligaments: These ligaments support the pubic symphysis.
3. Sacrotuberous Ligament: Extends from the sacrum to the ischial tuberosity, providing stability.
4. Sacrospinous Ligament: Connects the sacrum to the ischial spine, contributing to pelvic stability

Question 5

Blood Vessels of the Pelvis

Answer 5

The pelvic region is supplied by several important blood vessels:

1. Internal Iliac Artery: This artery branches from the common iliac artery and supplies blood to the pelvic organs, gluteal region, and perineum.
2. External Iliac Artery: This artery continues into the lower limb as the femoral artery.
3. Veins: Corresponding veins accompany the arteries and drain blood from the pelvic region, ultimately leading to the inferior vena cava.

Question 6

Nerves of the Pelvis

Answer 6

The pelvis is innervated by several key nerves:

1. Sacral Plexus: Formed by the ventral rami of the sacral spinal nerves (S1-S4), it gives rise to several important nerves, including the sciatic nerve, which innervates the lower limb.
2. Pudendal Nerve: This nerve is responsible for sensory and motor innervation to the perineum and pelvic floor muscles.
3. Pelvic Splanchnic Nerves: These provide autonomic innervation to pelvic organs