Trans - Pelvis Flashcards
What separates the major and minor pelvis?
Superior pelvic aperture / pelvic brim
Major route of communication between pelvic cavity and lower limb
Greater sciatic foramen
Prior to puberty, the ilium, ischium, and pubis are three separate bones connected by:
Triradiate cartilage
T/F: The greater sciatic foramen serves as the entry point of neurovascular structures to the abdominal cavity
F. It serves as the exit. The lesser sciatic foramen is the entry point
In obstetrics, the most important pelvic diameter measured is:
Anteroposterior, because it is the shortest diameter
Most adequate diagonal conjugate for childbirth
Greater than or equal to 11.5 cm
Boundaries of the pelvic outlet
Anterior: pubic symphysis
Posterior: sacrum, coccyx
Lateral: ischial tuberosity
The normal female pelvic type is termed:
Gynecoid – pelvic inlet is rounded, oval shape, transverse diameter is wide
What muscle makes up most of the lateral pelvic wall?
Obturator internus
Largest muscle in the pelvic floor
Levator ani
Part of the levator ani that forms a muscular sling around the anorectal junction
Puborectalis
During childbirth, what is the most likely muscle to be injured? Why?
Pubococcygeus, because of its proximity to the uterus
In females, what are the two potential spaces in the pelvic area?
Vesicouterine: between bladder and uterus
Retrouterine / pouch of Douglas: between rectum and uterus
Serves as a bed for the sacral and coccygeal plexuses
Piriformis
Main nerve of perineum and chief sensory nerve of external genitalia
Pudendal nerve
T/F: The inferior gluteal nerve supplies both the gluteus maximus and the gluteus minimus
F. The superior gluteal nerve innervates both muscles. The inferior gluteal nerve only innervates gluteus maximus
T/F: The superior gluteal artery arises from the posterior division of the internal iliac artery
T
The artery supplying the ductus deferens and prostate originates from where?
inferior vesicular artery
The pelvic girdle is composed of:
- Innominate bones – ilium, ischium, pubis
2. Sacrum and coccyx
Dimples at buttocks are at the level of:
PSIS
When in a sitting position, a person is resting on his/her ________
Ischial tuberosity
Attachment of the inguinal ligament in the pelvis
Pubic tubercle
Sharp oblique ridge at the lateral part of the superior pubic ramus
Pectineal line / pecten pubis
The pubic arch is formed by:
Ischiopubic rami of both sides of the pelvis
How many longitudinal crests are on the dorsal part of the sacrum
5
Median sacral crest is formed from:
Fused spinous processes
Intermediate sacral crest is formed from:
Fused articular processes
Lateral sacral crest is formed from:
Fused transverse processes
`The coccyx is formed from the fusion of how many rudimentary vertebrae
4
Strongest ligament in the body
Sacroiliac ligament
Thickenings on the superior and inferior aspect of the pubic symphysis
Superior: superior pubic ligament
Inferior: arcuate ligament
Narrowest diameter which a baby has to pass through during childbirth
Obstetric conjugate
T/F: The obstetric conjugate is directly measurable
F, because the bladder is in the way
The diagonal conjugate is measured from:
Inferior end/base of the pubic bone to sacral promontory
The pelvic midplane is at the level of the:
Ischial spine
Common pelvic types in males
Android
Anthropoid
Exit of the urethra and vagina through the pelvic diaphragm
Urogenital hiatus
Sacral plexus: components
Lumbosacral trunk (L4, L5), ventral rami of S1-S4
Branches of the sacral plexus
- Sciatic nerve – lower limb
- Pudendal nerve – external genitalia
- Superior gluteal nerve – gluteus medius and minimus
- Inferior gluteal nerve – gluteus maximus
Obturator nerve arises from what plexus
Lumbar plexus
Superior gluteal nerve innervates:
gluteus medius
gluteus minimus
Inferior gluteal nerve innervates:
gluteus maximus
Obturator nerve innervates:
Medial thigh muscles
Coccygeal plexus: components
Ventral rami of S4, S5
Coccygeal nerves
The pudendal nerve splits the fascia of the obturator internus to form _________
Pudendal canal / Alock’s canal
The anterior division of the internal iliac artery mainly supplies ________
Organs and viscera
The posterior division of the internal iliac artery mainly supplies ___________
Muscles
Males: inferior vesical artery :: females:_______________
Vaginal artery
The superior vesical artery originates from ___________
Umbilical artery
Terminal branch of the internal pudendal artery
Dorsal artery of penis or clitoris
Females: uterine artery :: Males: ___________
Artery to the ductus deferens
The uterine artery passes directly ________ to the ureter
Superior
Iliolumbar artery supplies __________
Posterior abdominal muscles (iliacus, psoas major, quadratus lumborum)
Lateral sacral artery supplies __________
Spinal meninges and spinal nerves
In females, what vessels enter the true pelvis
2 Internal iliac
2 ovarian
1 median sacral
1 superior rectal
In males, what vessels enter the true pelvis
2 internal iliac
1 median sacral
1 superior rectal
Main venous drainage of the pelvis
Internal iliac vein
Pelvic venous plexuses are formed by which veins
Rectal
Vesical
Uterine
Prostatic
Obturator foramen is formed by:
ramus of ischium
anterior ramus of pubis
The sacral promontory is the:
body of S1
Inferior borders of pubic arch define the:
subpubic angle
Structure covering the obturator canal
obturator membrane
Anterior sacrococcygeal joint is held together by:
anterior longitudinal ligament
Posterior sacrococcygeal joint is held together by:
posterior longitudinal ligament
the sacroilac ligament is supported by which other ligaments?
- sacrotuberous ligament
2. sacrospinous ligament
3 planes through which the head of the baby must exit in childbirth
- Superior pelvic aperture
- Pelvic midplane
- Inferior pelvic aperture
the pelvic brim is formed by:
1, promontory and ala of sacrum
2. right and left linea terminalis - arcuate line, pecten pubis, pubic crest
continuation of pecten pubis in ilium
arcuate line
elevations and depressions on surfaces of ilium and sacrum produce:
interlocking of bones, giving the sacroiliac joint more strength and stability
Sacroiliac joint: type of joint
synovial
most uncommon pelvic type
platypelloid
Components of lateral pelvic wall
- ilium and ramus of ischium
2. obturator internus muscle
Components of posterior pelvic wall
- sacrum
- ilium
- sacroiliac joint
- piriformis muscle
The piriformis exits at the
greater sciatic foramen
The obturator internus exits at the
lesser sciatic foramen
Piriformis: action
laterally rotate thigh
Components of the pelvic floor
- levator ani
2. coccygeus
Membrane that closes the urogenital hiatus
perineal membrane
Shape of pelvic diaphragm
hammock-shaped - deeper at the central part, shallower at the end
T/F: the pelvic diaphragm is relaxed during forced expiration, coughing, and strong movements of the upper limbs
F, the pelvic diaphragm contracts/tightens during these actions to increase support to the viscera and increase abdominal pressure
Major consequence of denervation of levator ani
Fecal and urinary incontinence
Likely consequences of pubococcygeal injury
- uterine prolapse
- cystocoele
- rectocoele
Cystocoele: definition
bladder wall prolapse
Rectocoele: definition
rectal wall prolapse
T/F: the entire rectum is covered by peritoneum
F, the inferior third of the rectum does not have a peritoneal covering
T/F: the Fallopian tube is not entirely covered by the peritoneum on its posterior aspect
F, the Fallopian tube is entirely enclosed by peritoneum
The pelvic peritoneum covers what surfaces of the pelvic viscera?
Superior and lateral surfaces
The space between the peritoneum and the pelvic muscles/pelvic floor is covered by
Pelvic fascia
Pelvic fascia is a continuation of:
endoabdominal fascia
T/F: the entire uterus is mobile to allow for enlargement during pregnancy
F, the cervix of the uterus is an immobile structure
Visceral pelvic fascia: type of connective tissue
Loose connective tissue
The parietal pelvic fascia covers what structures
Obturator internus
Levator ani
Coccygeus
Piriformis
T/F: neurovascular structures in the pelvis lie intraperitoneally
F
T/F: in the pelvis, nerves are generally more lateral to the vessels
T
T/F: in the pelvis, the veins are generally more medial to the arteries
F
T/F: all branches of the sacral plexus exit through the greater sciatic foramen
F, the nerve to the piriformis does not exit the greater sciatic foramen
T/F: the pudendal nerve returns to the pelvis via the lesser sciatic foramen
T. It leaves the greater sciatic foramen, hooks around the ischial tuberosity, and reenters the pelvis through the lesser sciatic foramen
Obturator nerve exits the pelvis via:
obturator foramen
The coccygeal plexus innervates:
coccygeus
The birfurcation of the common iliac arteries into the internal and external iliac arteries occurs at what level
L5-S1
Main artery of pelvis
Internal iliac artery
The internal iliac artery divides into anterior and posterior divisions near the __________
obturator foramen
T/F: the inferior vesicular artery may be found in both sexes
F, it is only found in males. its counterpart in females is the vaginal artery
The artery to the ductus deferens and the artery to the prostate are branches of:
inferior vesicular artery
Inferior vesicular artery: structures supplied
bladder, seminal vesicle, prostate
At the junction of the uterus and the vagina, the uterine artery passes over what structure
Ureter
junction of vagina and uterus
vaginal fornix
Critical areas of possible ureter ligation
- When ligating the uterine arteries near the lateral vaginal fornix
- When ligating ovarian vessels near the pelvic brim
Only branch in the anterior division of the internal iliac that supplies muscles
Inferior gluteal artery
Unpaired artery arising from the posterior surface of aorta near the pelvis
Median sacral artery
T/F: the ovarian artery lies anterior to the ureter as it enters the pelvic brim
F. The artery lies adjacent to the ureter as it enters the pelvic brim
The ovarian artery runs within what structure
suspensory ligament of ovary
Largest tributary of internal iliac vein
Superior gluteal vein
Lateral sacral veins drain into
internal vertebral venous plexus
