Sievert: Anal Triangle Flashcards
What does the sacrospinous ligament connect?
the sacrum to the ischial spine
What does the sacrotuberous ligament connect?
the sacrum to the ischial tuberosity
Above the ischial spine is a large notch, the (blank), which is converted into a foramen by the sacrospinous ligament
greater sciatic notch
Final segment of vertebral column
coccyx
Why are the greater and lesser sciatic foramen important?
They allow for nerves and vessels to leave the pelvis and enter the perineum without puncturing the pelvic floor.
The obturator foramen is filled with the (blank)
obturator membrane
What two muscles arise from the obturator membrane and act on the hip joint?
the obturator externus and the obturator internus
How does the obturator internus leave the pelvis to attach to the femur?
It passes through the lesser sciatic foramen
The area inferior to the pelvic diaphragm between the coccyx and the pubis and including all the structures in the two triangles
perineum
Pyramidal fibromuscular mass in the middle line of the perineum at the junction between the urogenital triangle and the anal triangle
perineal body
Perineal body is found in both males and females. In males, it is found between the (blank) and the anus; in females, is found between the (blank) and anus
bulb of the penis; vagina
Two muscles that make up the pelvic floor
levator ani and coccygeus
T/F: There is a dense connective tissue membrane over the obturator internus that forms a tendinous arch
True
The anal triangle in the female is identical to that of the male, but the UG triangle in the female has an additional opening for the (blank)
vagina
How do you get nerves and blood vessels out of the pelvis?
Through the greater sciatic foramen
Vessels and nerves can leave the pelvis through the greater sciatic foramen and then pass into the perineum by running superficial to the (blank) lig. but deep to the (blank) lig
sacrospinous; sacrotuberous
What is the purpose of the vessels leaving the pelvis through the greater sciatic foramen to enter the perineum?
Does not compromise the integrity of the pelvic floor
Boundaries of the ischio anal fossa
Medial: external anal sphincter and Pelvic diaphragm
Lateral: obturator muscle and ischium
Superior: pelvic diaphragm
Posterior: sacrotuberous lig. and gluteus maximus Inferior: Skin
Anterior boundary extends all the way forward to the pubis as the anterior recess
3 things in the anal triangle
- anal canal
- ischioanal fossa
- pudendal nerves and vessels as they pass thru on their way to the UG triangle
As the pudendal nerves pass through the anal triangle toward the UG triangle, what is the first branch they give off?
inferior rectal vessels and nerves
THis muscle is key, because superior gluteal nerves and vessels enter the gluteal region superior to the muscle, while inferior gluteal nerves and vessels enter inferior to this muscle
piriformis muscle
The pudendal nerve exits the pelvis via the greater sciatic foramen, passes superficial to the (blank) ligament, and enters the perineum passing deep to the (blank) ligament
sacrospinous; sacrotuberous
Once in the ischioanal fossa, the pudendal nerve gives off the (blank) and then enters the pudendal canal to travel anteriorly towards the UG triangle.
inferior rectals
The pudendal nerve supplies (blank) innervation to the external sphincter and UG triangle muscles, and (blank) innervation to the perineum.
motor; sensory
The internal pudendal artery and vein follow the (blank) into the canal giving off similar branches.
pudendal nerve
Rectum is approximately 10 cm in length and begins at the (blank) vertebra and extends to the (blank).
S3; rectoanal junction
Where does the anal canal begin? Where does it end?
At the superior limit of the pelvic diaphragm-where the rectal ampulla narrows; anus
The pectinate line marks the point where (blank) motor and sensory above give way to (blank) motor and sensory below
viscero; somatic
The pectinate line is also the point of junction between the embryonic (blank) and the proctodeum.
hindgut
Three blood supplies to the anal canal Which vessel(s) are a branch of the IMA? Which vessel(s) are a branch of the common iliacs?
superior, middle, and inferior rectals
Superior rectal from the IMA
Middle and inferior from the pectinate, which comes off of the common iliacs