The Pelvis as a Region of Anatomy of the Body Flashcards
List the surface areas of the abdomen on the left and right sides from superficial to inferior.
1 - Hypochondriac.
2 - Lumbar.
3 - Iliac.
List the surface areas of the abdomen on the central line from superficial to inferior.
1 - Epigastric.
2 - Umbilical.
3 - Hypogastric.
List the superior, inferior, anterior, posterior and lateral borders of the abdominopelvic cavity.
- Superior:
1 - The inferior border of the diaphragm.
Inferior:
1 - Pelvic floor.
2 - Perineum.
Anterior:
1 - Anterior abdominal muscles (anterosuperior).
2 - Anterior border of bony pelvis (anteroinferior).
Posterior:
1 - Ribs (posterosuperior).
2 - Vertebral column (posterosuperior).
3 - The sacrum (posteroinferior).
Lateral:
1 - Ribs (superolateral).
2 - Thigh (inferolateral).
List the bones of the pelvis.
1 - Sacrum.
2 - Ilium.
3 - Ischium.
4 - Pubis.
5 - Coccyx
What are the superior and inferior apertures of the pelvis otherwise known as?
- The superior aperture is also known as the pelvic inlet.
- The inferior aperture is also known as the pelvic outlet.
List the palpable bony components of the pelvic inlet.
1 - Highest point, known as the supracristal plane.
2 - Middle point, known as the transtubercular plane.
3 - Lowest point known as the pelvic brim.
Which vertebral level corresponds to the highest palpable point of the pelvic inlet / the supracristal plane?
L3/4 intervertebral disc.
List 2 anatomical structures that occur at the level of the supracristal plane.
1 - The bifurcation of the abdominal aorta into the common iliac arteries.
2 - The umbilicus.
Which vertebral level corresponds to the middle palpable point of the pelvic inlet / transtubercular plane?
L5.
Which structures does the transtubercular plane intersect?
The iliac tubercles.
Which bony component of the pelvis forms the pelvic brim?
The pubic crest.
Which structure divides the pelvis into the greater and lesser pelvises?
The pelvic brim.
List the contents of the greater pelvis.
1 - Colon.
2 - Iliacus.
3 - Psoas major and minor.
List the contents of the lesser pelvis.
1 - Reproductive system.
2 - urinary system.
3 - Terminal portion of the digestive system.
Which artery supplies all of the organs of the lesser pelvis?
The internal iliac artery.
What is the rectovesical pouch?
- In the male pelvis, the parietal peritoneum separates the urinary bladder (anteriorly) from the rectum (posteriorly).
- As the parietal peritoneum courses between the two, it forms a pouch known as the rectovesical pouch.
What are the rectouterine and vesicouterine pouches?
- In the female pelvis, the parietal peritoneum separates the urinary bladder (anteriorly) from the uterus (midway) and the rectum (posteriorly).
- As the parietal peritoneum courses between the three, it forms two pouches - the rectouterine and vesicouterine pouches.
What is the rectouterine pouch otherwise known as?
The pouch of Douglas.
What is the space of Retzius?
The potential space between the pubic symphysis and the bladder.
What is the perineal body?
How does it affect the appearance of the region in which it is found?
- A thickening of fascia in the pelvic floor that acts as a point of attachment of muscles.
- It causes the pelvic floor to adopt a hammock-like shape.
List the anterior, posterior and lateral attachments of the pelvic floor.
- Anteriorly, the pubis.
- Posteriorly, the coccyx.
- Laterally, a thickened band of the obturator fascia.
What are the urogenital and anal triangles?
- The pelvic outlet has a diamond shape.
- If a horizontal line is drawn through the perineal body, the diamond is bisected into two triangles.
- The anterior triangle is known as the urogenital triangle.
- The posterior triangle is known as the anal triangle.
Which structure defines the openings of the urethra and vagina?
The perineal membrane.
What structure anchors the perineal membrane at the midline?
The perineal body.
List 5 muscles anchored at the perineal body.
1 - The external anal sphincter.
2 - The external urethral sphincter.
3 - Superficial transverse perineal muscle.
4 - Deep transverse perineal muscle.
5 - Bulbospongiosus.
List the layers of the pelvic floor from superior to inferior.
Which of these layers comprise the pelvic diaphragm?
The pelvic floor consists of the pelvic diaphragm and perineum:
1 - Internal layer of fascia.
2 - Levator ani (anteriorly) and coccygeus muscles (inferiorly).
3 - External layer of fascia.
4 - Perineal membrane.
5 - Perineum.
- Layers 1-3 comprise the pelvic diaphragm.
What is the superficial perineal pouch?
A potential space between the perineal membrane and the perineum.
What is the deep perineal pouch?
A potential space between the external layer of fascia of the pelvic diaphragm and the perineal membrane.
List the muscles comprising the levator ani.
Which muscle forms the main part of levator ani?
1 - Puborectalis.
2 - Pubococcygeus (main muscle).
3 - Iliococcygeus.
Describe the course of the puborectalis muscle.
What is the function of its shape?
- Arises from the pubis.
- Passes posteriorly to unite with the other puborectalis muscle, forming a U shaped sling around the anorectal junction.
- The sling maintains anorectal flexure, contributing to continence.
- Some fibres of puborectalis insert into the deep part of the external anal sphincter.
How does the puborectalis muscle differ between males and females?
- In males, some fibres pass more anteriorly around the prostate, forming the levator prostatae muscle.
- In females, some fibres pass as a sling behind the vagina, inserting into the perineal body and forming the pubovaginalis muscle.
Describe the course of the pubococcygeus muscle.
- It arises from the pubis.
- It runs posteromedially to insert into the coccyx and anococcygeal ligament.
How does the pubococcygeus muscle differ between males and females?
In females, it also encircles the urethra, vagina and anus, merging into the perineal body.
Describe the course of the iliococcygeus muscle.
- It arises from the lateral pubic symphysis.
- It travels laterally over the obturator internus.
- It meets in the midline with the other iliococcygeus muscle and continues to insert at the coccyx.
