Anatomy Anal Triangle Flashcards
What does the pelvis refer to?
the region above the pelvic diaphragm
What does the perineum refer to?
the region below the pelvic diaphragm
What is the pelvis made up of?
the ischial spine obturator foramen pubic symphysis ischial tuberosity coccyx greater sciatic notches lesser sciatic nothces
What are the three ligaments that are extremely important for the structural integrity of the pelvis?
SI joint ligament
Sacrospinous ligament
sacrotuberous ligament
What 2 ligaments stabilize the SI joint?
The sacrospinous ligament and the sacrotuberous ligament
What is a combination of numerous named ligaments?
the SI joint
What do the sacrospinous and sacrotuberous ligaments make?
they turn the greater and lesser notches into foramina
The obturator foramen is filled in with (blank)
obturator membrane
What two muscles arise from the obturator membrane and act on the hip joint?
the obturator externus and the obturator internus
two triangles fill in the area of the perineum, what are these 2 triangles?
the anal triangle
the urogenital triangle
The (blank) is defined as the area inferior to the pelvic diaphragm between the coccyx and the pubis and including all the structures in the two triangles.
perineum
The midsaggital point separating the 2 triangles is also known as the perineum by obstetricians but is really the (Blank)
perineal body
What is the pelvic floor made up of?
the levator ani and coccygeus (bowel shaped collection of muscles)
The obturator internus leaves the pelvis to attach to the (blank)
femur
In the female, the anal triangle is identical but the (blank) has an additional opening for the vagina.
UG
How do we get nerves and blood vessels out of the pelvis?
leaves the pelvis via the greater sciatic foramen and then pass into the perineum by running over superfical to the sacrospinous ligament but deep to the sacrotuberous ligament.
Why do the nerves and blood vessels out of the pelvis travel the way that they do?
to allow them to have access to the perineum without compromising the integrity of the pelvic floor
What does the anal triangle contain?
contains the anal canal, the ischioanal fossa, and the pudendal nerves and vessels as they pass through on their way to the UG triangle.
What does the pudendal nerves and vessels give off along their way to the UG triangle?
inferior rectal vessels and nerves
What are the boundaries of the ischio anal fossa?
external anal sphincter andlevator ani medial, obturator muscle and ischium lateral, levator ani superior, sacrotuberous lig. and gluteus maximus posterioly.
What is the medial boundary of the ischio anal fossa?
external anal sphincter and levator ani medial
What is the lateral boundary of the ischio anal fossa?
Obturator muscle and ischium lateral
What is the superior boundary of the ischio anal fossa?
pelvic diaphragm/ levator ani
What is the posterior border of the ischio anal fossa?
sacrotuberous lig. and gluteus maximus
What is the inferior border of the ischio anal fossa?
skin
What is the anterior border of the ischio anal fossa?
anterior border extends all the way forward to the pubis as the anterior recess.
How do you expose deep gluteal muscles and piriformis?
reflect gluteus maximus muscle
What enter superiorly and inferiorly to the piriformis muscle?
gluteal nerves and vessels
Why do pudendal nerves and vessels leave the pelvis?
to gain the perineum
Where does the pudendal nerve exit?
greater sciatic foramen
The pudendal nerve exits the greater sciatic foramen passing (blank) to the sacrospinous lig and gains the perineum passing deep to the sacroptuberous lig.
superificial
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
What does the pudendal nerve innervate?
the external sphincter and the UG trangle muscles and is the sensory nerve of the perineum
the internal pudendal artery and vein follow the pudendal nerve into the pudendal canal giving off (blank)
branches such as the inferior rectal vessels :)
Where will you find the obturator internus?
Goes from obturator membrane through the greater sciatic foramen to the femur
Where do you find the levator ani?
it is the base of the bowl so it goes from anterior to posterior and the 2 halfs of the levator ani meet at the posterior midline.
In the the levator ani, there is a hole in the membrane that makes what?
a urogenital hiatus (females->vagina and urethra go through here, males -> urethra)
THe coccygeous muscle is located where?
more posterior and superior to the levator ani
What all does the pudendal canal have within it?
pudendal nerve, artery and vein
(blank) is approx. 10 cm in length and begins at the S3 vertebra and extends to the rectoanal junction.
rectum
The anal canal begins at the superior limit of the (blank) where the rectal ampulla narrows and ends at the anus.
pelvic diaphragm
What is the superior border of the anal columns?
What is the inferior border of the anal columns?
Superior border->junction b/w rectum and anal canal
inferior border->anus