204: DR 1 Pelvic Region

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What forms the pelvic floor?

Coccygeus + Levator ani (correct)

Iliococcygeus + Pubococcygeus

Levator ani + Puborectalis

Coccygeus + Levator ani + Puborectalis

Which joint is classified as a secondary cartilaginous joint?

Lumbosacral joint

Iliolumbar joint

Sacroiliac joint

Pubic symphysis (correct)

Which nerve supplies the Coccygeus and Levator ani?

Obturator nerve

Femoral nerve

Nerve to Levator ani (S4) (correct)

Pudendal nerve (S2,3,4)

What structures form the pelvic inlet?

Promontory, Ala of sacrum, Terminal line Signup and view all the answers

What is the classification of the Sacroiliac joint?

Synovial and fibrous joint Signup and view all the answers

At which vertebral level does the aorta bifurcate to form the common iliac arteries?

L4 Signup and view all the answers

What is the main component of the lesser pelvis?

Viscera of pelvic cavity, sacral plexus, branches of internal iliac artery Signup and view all the answers

What is the name of the artery formed after the internal iliac artery passes inferior to the inguinal ligament?

Femoral artery Signup and view all the answers

Which layer is not part of the lateral region of the abdominal wall?

Rectus abdominis muscle Signup and view all the answers

What muscles form the Levator ani?

Puborectalis + Pubococcygeus + Iliococcygeus Signup and view all the answers

What is the main component of the greater pelvis?

Small intestines, sigmoid colon, cecum, appendix Signup and view all the answers

What is the additional layer needed to pass through to reach the uterus?

Visceral peritoneum Signup and view all the answers

What is the Sacrotuberous ligament part of?

Pelvic outlet Signup and view all the answers

What is the sympathetic outflow from the spinal cord?

T1-L2 Signup and view all the answers

What three bones form the innominate?

Ilium, Ischium, Pubis Signup and view all the answers

What is the main nerve supplying the Coccygeus and Levator ani muscles?

Nerve to Levator ani (S4) Signup and view all the answers

What is the level of bifurcation of the aorta?

L3-L4 intervertebral disc Signup and view all the answers

Which artery is formed after the internal iliac artery passes inferior to the inguinal ligament?

Femoral artery Signup and view all the answers

Study Notes

Innervation and Blood Supply

Coccygeus and Levator ani muscles primarily supplied by nerve to levator ani (S4).
Levator ani also receives inferior contributions from the Pudendal nerve (S2,3,4).

Aortic Bifurcation

Common iliac arteries formed by the bifurcation of the aorta.
Typically occurs at the L4 vertebral level.
Internal iliac artery becomes the femoral artery upon passing inferior to the inguinal ligament.

Layers of the Abdominal Wall

Lateral Region (Superficial to Deep):
- Skin
- Camper’s fascia
- Scarpa fascia (inferiorly)
- External oblique muscle/aponeurosis
- Internal oblique muscle/aponeurosis
- Transversus abdominis muscle/aponeurosis
- Transversalis fascia
- Parietal peritoneum
- Peritoneal cavity
Anterior Paramedian Position (Above Arcuate Line):
- Skin
- Camper's fascia
- Scarpa’s fascia (inferiorly)
- Anterior rectus sheath
- Rectus abdominis muscle
- Posterior rectus sheath
- Transversalis fascia
- Parietal peritoneum
- Peritoneal cavity
Anterior Paramedian Position (Below Arcuate Line):
- Skin
- Camper's fascia
- Scarpa’s fascia (inferiorly)
- Anterior rectus sheath
- Rectus abdominis muscle
- Transversalis fascia
- Parietal peritoneum
- Peritoneal cavity
Additional layer to reach the uterus: Visceral peritoneum.

Sympathetic Outflow

Sympathetic outflow from the spinal cord originates from specific vertebral levels (not explicitly detailed in the content).

Pelvic Anatomy

Innominate Bones: Identify three bones forming the innominate and their boundaries.
Pelvic Joints:
- Sacroiliac joints: Synovial and fibrous joint.
- Pubic symphysis: Secondary cartilaginous joint.

Pelvic Apertures

Pelvic Inlet Components:
- Promontory
- Ala of sacrum
- Terminal line (includes arcuate line, lectin pubis, pubic crest).
Pelvic Outlet Components:
- Coccyx
- Sacrotuberous ligament
- Ischiopubic ramus
- Pubic symphysis.

Pelvis Regions

Greater Pelvis: Above pelvic inlet contains small intestines, sigmoid colon, cecum, appendix.
Lesser Pelvis: Below pelvic inlet contains pelvic viscera, sacral plexus, branches of internal iliac artery, sacral sympathetic chain, hypogastric nerve, inferior hypogastric plexus, pelvic and sacral splanchnics.

Pelvic Floor Musculature

Pelvic floor consists of Coccygeus (ischiococcygeus) and Levator ani.
Levator ani is composed of Puborectalis, Pubococcygeus, and Iliococcygeus.
Review of motor innervation to these pelvic floor muscles is essential for understanding their function.