30- Anatomy of the Pelvis Flashcards
Define Pelvic Diaphragm
Partition between the pelvic cavity and the
perineum.
What muscles make up the pelvic diaphragm?
Levator ani
Coccygeus
What provides support for pelvic organs?
Condensation of the pelvic diaphragm that form ligaments surrounding the following structure:
Neck of uterus
Cervix of Uterus
Are there any openings in the pelvic diaphragm?
Yes, 2 midline apertures in males and 3 in females [urethra, vagina, and rectum]
Which part of the pelvic diaphragm is covered by pelvic fascia?
Upper surface
what muscles compose the Levator ani muscle?
3 paired muscles [M → L]
Puborectalis
Pubococcygeus
Iliococcygeus
What is the nerve supply of Levator ani muscle?
4th sacral nerve
Perineal branch of pudendal nerve [S2-S4]
Define Anatomical conjugate
Distance between the upper margin of the pubic symphysis to promontory and is about 12-cm.
Define Obstetrical conjugate
Distance between the posterior surface of the symphysis to promontory
What is the length of Obstetrical conjugate [OC]?
11.5-cm.
Define Diagonal conjugate
Distance between the inferior pubic ligament to promontory
What is the length of Diagonal Conjugate?
13-cm
Which Anterioposterior measurement can be measured by digital examination in females?
diagonal Conjugate
What is the length of the Pelvic outlet in females?
12.5 cm
What is the length of transverse diameter of pelvic inlet?
13.5 cm
What is the sacral promontory?
Most superior surface on the body of the first sacral vertebrae
What are the boundaries of the Pelvic outlet?
Anterior: Lower margin of pubic symphysis with arcuate pubic ligament Posterior: tip of coccyx Laterally: Conjoint ischiopubic rami [AL] Ischial Tuberosity [L] Sacrotuberous Ligaments [PL]
What are the anterioposterior and transverse diameters of the pelvic outlet?
AP diameter: 12.5
Transverse diameter: 10 cm
What measurements of the pelvis may cause difficulties during deliveries?
OC < 10 cm
Transverse diameter < 8.5 cm
What are the four type of Females Pelvises?
Gynecoid
Android
Anthropoid
Platypelloid
Which female pelvis is most suitable for normal vaginal delivery?
Gynecoid
Describe Gynecoid pelvis
Circular inlet
Describe Android pelvis
Triangular inlet Prominent ischial spine More angulated Pubic arch [< 90°] Heart shaped pelvis resembles male pelvis
Describe Anthropoid pelvis
AP diameter is longer than transverse diameter
Descrive Platypelloid Pelvis
Flat pelvis with kidney shaped brim
AP diameter is reduced
Transverse diameter is increased
What condition causes Platypelloid pelvis?
Vitamin D deficiency [osteomalacia]
List the type of female pelvises and if each are suitable for normal vaginal delivery
Gynecoid → best chance for normal delivery
Android → least suitable for normal delivery
Anthropoid → Difficulty in delivery
Platypelloid → normal delivery not possible
What is the function of the Puborectalis?
maintains forward angulation between rectum and anal canal
Maintains fecal continence