Exam #4: Pelvis I Flashcards
Where is the arcuate line? How is the arcuate line related to the pectineal line?
Arcuate line= medial aspect of the ilium
Pectineal line= continuation of the arcuate line on the pubis
What forms the obtruator foramen?
Ramii of the pubis & ischium
What defines the pelvic brim?
1) Pectinal line of pubis
2) Arcuate line of ilium
3) Sacral promontory
*Also known as pelvic inlet
Greater pelvis vs. lesser pelvis
Lesser pelvis= inferior to true pelvis defined by the pelvic brim & superior to pelvic outlet
Greater pelvis= lower part of the abdominal cavity, superior to pelvic inlet
What is the sacrospinous ligament?
Ligament connecting sacrum to iliac spine
- Forms the greater sciatic foramen
What is the sacrotuberous ligament?
Ligament connecting sacrum to ischial tuberosity
- Forms the lesser sciatic foramen
What are the sex differences between the male & female pelvis? Specifically address: Ileum, pelvic inlet, pelvic canal, ischial tuberosity & spine, greater sciatic notch, subpubic angle, & coccyx.
Ileum - Male= elongated - Female= flared & lateral Pelvic inlet - Male= heart-shaped - Female= oval/ round Ischial tuberosity & spine - Male= not everted & partially obstructs pelvic outlet - Female= everted Greater sciatic notch - Male= narrow - Female= broader Subpubic angle Coccyx - Male= anterior; partially obstructs like IT & spine - Female= more posterior
What muscle forms the lateral muscular wall of the pelvis?
Obtruator internus (overlies the obtruator foramen)
Where does the obtruator internus attach?
Femur’s greater trochanter
What muscle forms the posterior muscular wall of the pelvis?
Piriformis muscle
What is the clinical relevance of the piriformis muscle?
“Bed” for the sacral nerve plexus
What is the important anatomical landmark of the pelvic floor?
Ischial spine
What overlies the ischial spine?
Tendinous arch where the muscles of the pelvic floor attach
What two groups of muscles form the pelvic floor i.e. pelvic diaphragm?
- Levator ani
- Coccygeus
What is the function of the pelvic diaphragm?
1) Support of abdominal viscera in times of increased intra-abdominal pressure
2) Aid in voluntary control of urination & defecation
What muscles form the levator ani?
1) Puborectalis- forms muscular sling arising from pubis that wraps around rectum
2) Pubococcygeus- pubis & tendinous arch–>coccyx
3) Iliococcygeus- tendinous arch & ischial spine–> blend w/ pubococcygeus
What is the function of the puborectalis?
Maintain fecal continence
Clinically, & esp. when performing a hysterectomy, what is important to remember about the ureters?
In females, ureters pass medial to the uterine arteries
What structure criss-crosses the ureters in males?
Ductus Deferens
What spinal levels provide sympathetic innervation to the ureters? How is this important clinically?
- T11-L2
- Responsible for waves of descending referred pain w/ renal stones
What provides parasympathetic innervation to the ureters?
S2-4 & some vagus
What are the four different parts of the bladder?
Apex= anterosuperior aspect near pubic symphysis Fundus= posterior wall Body= between apex & fundus Neck= Inferior constriction of bladder
What is the trigone?
Triangle between ureteric orifices (posterior) & internal ureteric meatus (neck of bladder)
What muscle forms the walls of the bladder?
Detrusor muscle
