Pelvic Walls and Floor Flashcards
What bones make up the pelvis
Sacrum (x1)
Innominate or hip bone (x2)
What is the hole in the inferior section of the pelvis called
Obturator foramen
What part of the pelvis do we sit on
Ischial tuberosity
Name the 3 main joints throughout the pelvis; and what type of joint are they
- Lumbosacral joint (secondary cartilaginous)
- Sacroiliac joint (synovial plane)
- Pubic symphysis (secondary cartilaginous)
What structures make up the anterior wall of the pelvis
Pubic bodies, pubic rami and pubic symphysis
What structures make up the posterior wall of the pelvis
Sacrum, coccyx and piriformis
Describe the floor of the pelvis
The floor is muscular and composes the pelvic diaphragm
Name the 4 ligaments within the pelvis
- Posterior sacroiliac (fibrous)
- Anterior sacroiliac (synovial)
- Sacrospinous
- Sacrotubercle
Name the common pelvic outlets in males and females
Male = Android Female = Gynecoid
Where does the iliacus muscle travel from and to
Iliac fossa, joins the psoas muscle (forming the iliopsoas) and inserts into the lesser trochanter of the femur
What nerve innervates the iliacus muscle
Femoral
What is the function of the iliacus muscle
Hip flexion
Where does the psoas muscle travel from and to
T12-L4 bodies and IV discs (superficial) and L1-L5 (deep), joins the iliacus (forming the iliopsoas) and inserts into the lesser trochanter of the femur
What is the function of the psoas muscle
Hip flexion, bend trunk laterally (one) and raise trunk from supine position (both)
What is the root value of the psoas muscle
Lumbar plexus direct branches L2-L4 anterior rami
Where does the obturator externus muscle pass from and to
Outer surface of the obturator membrane to the trochanteric fossa of femur
Where does the obturator internus muscle pass from and to
Inner surface of the obturator membrane to medial surface of greater trochanter of femur
What is the function of the obturator internus
Lateral rotation of the hip
What is the innervation of the obturator internus
Nerve to obturator internus direct from sacral plexus (L5, S1)
Where does the piriformis muscle pass from and to
Pelvic surface of the sacrum to the greater trochanter of the femur
What is the function of the piriformis
Lateral rotation of the hip joint
What nerve innervates the piriformis
Nerve to piriformis (S1, S2)
What structures pass through the obturator foramen
- Obturator artery
- Obturator vein
- Obturator nerve
What does the pelvic diaphragm prevent
It prevents any prolapse of structures within the pelvic cavity
What muscles form the pelvic diaphragm
- Levator ani (iliococcygeus, pubococcygeus, puborectalis)
2. Coccygeus
Where does the coccygeus muscle pass from and to
Ischial spine and sacrospinous ligament to the coccyx and inferior sacrum
What is the function of the coccyeus
Supports the pelvic viscera and flexes the coccyx
What is the root value of the coccygeus muscle
S4, S5
What are the 3 different subdivisions of pubococcygeus
- Puborectalis (both sexes)
- Levator prostatae (males)
- Pubovaginalis (females)
What happens to levator ani during urination and defecation
It relaxes
Where do the most medial fibres of pubococcygeus insert into
The perineal body
What muscle fibres does the puborectalis muscle mix with
The external anal sphincter
What nerves innervate the puborectalis muscle
Pudendal nerve (S2-S4) and nerve to levator ani (S4)
Where does the iliococcygeus muscle attach to
Attaches to the fascia of obturator internus
What nerves innervate the iliococcygeus muscle
Pudendal nerve (S2-S4) and nerve to levator ani (S4)
What is the perineal body
Fibrous connective tissue located between the vagina/bulb of the penis, and the anus
What muscles attach to the perineal body
- Levator prostatae (males)
- Pubovaginalis (females)
- External anal sphincter
- Perineal muscles
What is the parietal pelvic fascia
Fascia that covers the internal wall and is thickened over the obturator internus to form the tendinous arch of the pelvis
What is the visceral pelvic fascia
Fascia that covers the organs
Where does the parietal and visceral pelvic fascia combine
They blend together as organs pierce the pelvic floor
What does endopelvic fascia acts as
It acts as a packing material around the organs
What are the two types of endopelvic fascia
- Loose
2. Condensed
