Pelvic Walls and Floor Flashcards
What are the posterior and anterior pelvic boundaries?
Bony walls
What is the lateral pelvic boundary?
Bony and muscular walls
What is the inferior pelvic boundary?
Muscular at the pelvic outlet
What is the superior pelvic boundary?
Is the inlet to the abdominal cavity
What is the function of the greater and lesser sciatic notches?
To allow the passage of nerves, arteries, veins and muscles from the internal surface of the pelvis to the perineum and gluteal region
What turns the sciatic notches into foramen?
The presence of ligaments
What foramen allows the anterior part of the pelvis to be lighter?
Obturator foramen
What structures keep the foramen closed?
- Obturator internis
- Obturator externis
- Obturator membrane
The obturator foramen is pierced by what structures?
Obturator nerve and vessels
What structure is a bony landmark for the pudendal nerve?
Ischial spine
What is the name of the bone at the site of the hip joint where the ball and socket joint forms with the femur?
Acetabulum
What do the iliac blades provide attachment for anteriorly and posteriorly?
Anterior - iliacus
Posterior - gluteus muscles
What structures of the pelvis are attachment sites for the inguinal ligament?
Anterior superior iliac spine
Pubic tubercle
What nerves pass through the sacral foramen to exit the vertebral column and supply the structures within the pelvis and lower limb?
Sacral nerves
What two large ligaments attach to the sacrum?
- Sacrotuberous
- Sacrospinous
What is the distal attachment of the sacrotuberous ligament?
The ischial tuberosity
What is the distal attachment of the sacrospinous ligament?
The ischial spine
Together, the sacrospinous and sacrotuberous form what strcuture?
The greater and lesser sciatic foramen
How is the inguinal ligament formed?
The aponeurosis of external oblique as it rolls over itself to form the anterior wall and floor of the inguinal canal
What type of joint is the anterior sacroiliac joint and what ligament protects it?
Plane synovial joint protected by the anterior sacroiliac ligament
What type of joint is the posterior sacroiliac joint and what ligament protects it?
Fibrous joint supported by the posterior sacroiliac ligament
Whatis the name of the classic female shape of the pelvis inlet?
Gynecoid
What is the name of the classic male shape of the pelvic inlet?
Android
What is the name given to a more flattened pelvic inlet in an anterior posterior direction?
Platypelloid
What is the name given to a wider pelvic inlet in an anterior posterior direction?
Anthropoid
What nerve innervates the iliacus muscles?
Femoral nerve
What is the action of the iliacus muscle?
To flex the hip
What nerve innervates the psoas muscle?
Anterior rami of L2-L4
What is the action of the psoas muscle?
Flex the hip
What is the main action of the obturator externus muscle?
- to abduct the thigh
- to laterally rotate the thigh
What muscle attaches to the membrane and sends its tendons through the the lesser sciatic notch to reach the femur?
Obturator internus
What tendon runs between the two glamelli muscles?
Obturator internus
What muscle is a useful landmark in the pelvis as the sciatic nerve and pudendal nerve form on its superior surface?
Piriformis
What is the main function of the piriformis muscle?
To support the pelvic wall by partially covering the opening of the greater sciatic foramen
What two muscle blocks form the pelvic diaphragm?
- Levator ani (anteriorly)
- Coccygeus (posteriorly)
What is the main function of the coccygeus muscle and what nerve is it innervated by?
- To flex the coccyx
- Direct branches from the sacral plexus (S4-5)
What are the two divisions of the levator ani?
- Pubococcygeus
- Iliococcygeus
What is the main function of the pubococcygeus muscle?
To support the vagina, prostate and rectum
What provides the levator ani with motor innervation?
- Nerve to levator ani
- Pudendal nerve
What two sections of the pubococcygeus muscle are found in males?
- Levator prostatae
- Puborectalis
What two sections of the pubbococcygeus muscle are found in females?
- Pubovaginallis
- Puborectalis
What nerve innervates the pubococcygeus muscle?
- Pudendal nerve
- Nerve to levator ani
What is the main function of the puborectalis muscle?
To maintain continence by bending the rectum
What nerve innervates the puborectalis muscle?
- Pudendal nerve
- Nerve to levator ani
What is the attachment site for the Iliococcygeus muscle?
Tendinous arch of levator ani
What nerve innervates the iliococcygeus muscle?
- Pudendal nerve
- Nerve to levator ani
What muscles from the pelvic region attach to the perineal body?
- Levator prostatae
- Pubovaginalis
- External anal sphincter
What pelvis fascia covers the internal wall?
Parietal pelvic fascia
What pelvis fascia covers the organs?
Visceral pelvic fascia
What pelvis fasica acts as packing material around the organs?
Endopelvic fascia
