anatomy of the pelvic floor

Question 1

what muscles make up the superficial layer of the pelvic floor

Answer 1

anteriorly we have; ischiocavernosus, bulbospongiosus, superficial traverse muscles
posteriorly we have the external anal sphincter

Question 2

where is the ischiocavernosus located?

Answer 2

it ranges from the ischial tuberosity and ischiopubic ramus all the way to the crus of the clitoris on either side

Question 3

what is the main function of the ischiocavernosus muscle?

Answer 3

maintains erection of the clitoris

Question 4

what nerve provides innervation to all of the anterior muscles of the perineum?

Answer 4

the perineal branch of pudendal nerve (S2-S4)

Question 5

Where is bulbospongiosus muscle located?

Answer 5

can be found directly on either side of the labia and ranges from the central tensdon of the perineum to the inferior fascia of the uro-genital diaphragm

Question 6

what is the function of bulbospongiosus muscle

Answer 6

it allows to decrease the vaginal opening and contributes to the erection of the clitoris

Question 7

where is the superficial transverse muscle of the perineum found?

Answer 7

found b/w the vaginal and anal opening; it ranges from the ischial tuberosity to the central tendon of the perineum

Question 8

where is the external anal sphincter located?

Answer 8

it ranges from the ano-coccygeal raffee to the central tendon of the perineum

Question 9

what muscles/types of muscles make up the external anal sphincter?

Answer 9

round muscles made up of circular fibers

Question 10

what is the role of the ano-coccygeal rafee for the EAS?

Answer 10

it immobilizes the sphincter front and back

Question 11

what is the role of the EAS?

Answer 11

It maintains the anal canal closed

Question 12

what nerves provide innervation to the EAS?

Answer 12

sacral nerve root 4 and inferior rectal branch of the pudendal nerve (S2-S4)

Question 13

What muscles make up the urgo-genital diaphragm

Answer 13

external urinary sphincter and the deep transverse muscles

Question 14

where is the external urinary sphincter located

Answer 14

its found in the urogential diaphragm and ranges from the inferior pubic ramus all the way to the vaginal wall

Question 15

what is the function of the EUS?

Answer 15

helps to maintain continence and expulses the last few drops of urine in males

Question 16

what provides innervation to the EUS?

Answer 16

perineal branch of the pudendal nerve

Question 17

how is the innervation of the EUS?

Answer 17

Its both somatic and autonomic since its made up of both smooth and striated muscles

Question 18

where is the deep transverse muscles of the pelvic floor located?

Answer 18

located in the urogenital diaphragm and ranges from the ischiopubic ramus near the ischial tuberosity and attaches to the central tendon of the perineum

Question 19

what is the function of the deep transverse muscles of the pelvic floor?

Answer 19

expulses the last few drops of urine and helps to support the neck of the bladder

Question 20

what provides innervation to the deep transverse muscles of the pelvic floor

Answer 20

perineal branch of the pudendal nerve

Question 21

what muscles make up the pelvic diaphragm

Answer 21

the pelvic diaphragm is the deepest layer of the PFM and it is made up of pubovaginalis muscles, puborectalis muscle, pubococcygeus muscle, iliococcygeus muscle

Question 22

what muscles make up the levator ani

Answer 22

pubovaginalis, puborectalis, pubococcygeus

Question 23

where is pubovaginalis located

Answer 23

in the pelvic diaphragm; it ranges from the most medial portion of the posterior surface of the pelvic bone and attaches to the urethra and central canal of the perineum

Question 24

what is the role of the pubovaginalis muscle

Answer 24

supports, elevates the PFM
supports changes of intraabdominal pressure
decreases the diameter of the vaginal hiatus

Question 25

what nerves innervates all of the muscles that make up the pelvic diaphragm

Answer 25

sacral nerve root 3 and 4 and perineal branch of the pudendal nerve

Question 26

where it the puboractalis muscle found

Answer 26

it ranges from the posterior surface of the pubis and lateral to the pubovaginalis muscle and attaches to the lateral portion of the anal canal and rectum junction to insert onto the ano-coccygeal raffee

Question 27

what is the role of the puborectalis muscle

Answer 27

supports and slightly elevates the pelvic floor. allows support to intraabdominal pressure changes
approximates anus to pubis and closes anus

Question 28

what happens when the ano-rectal angle is greater than 90 degrees

Answer 28

generally associtated with constipation

Question 29

what determines the ano-rectal angle

Answer 29

the tone of the puborectalis muscle; high tone generally leads to constipation

Question 30

where is the pubococcygeus muscle located

Answer 30

posterior surface of the pubis and attaches to the posterior surface of the anorectal junction and anococcygeal raffee ranging from the anus to coccyx
its found lateral to puborectalis muscle

Question 31

what is the role of the pubococcygeus muscle

Answer 31

supports and slightly elevated the pelvic floor
resists changes of intraabdominal pressure
approximates anus to pubis and closes anus
will function to pull everything anteriorly

Question 32

where is the iliococcygeus muscle found

Answer 32

ranges from the ischial spine and tendinous arch of levator ani to the distal portion of the coccyx and anococcygeal raffee

Question 33

what is the role of iliococcygeus muscle

Answer 33

supports and elevates the pelvic floor
resists intra-abdominal pressure
approximates anus to pubis and elevates anus

Question 34

where does the pudendal nerve pass

Answer 34

b/w piriformis and coccygeus muscle and will cross over the lateral part of the sacrospinous ligament to then re-enter via the lesser foramen

Question 35

what is the alcox canal

Answer 35

canal made of fascia found in the obterator internus muscle where the pudendal nerve exits

Question 36

how does the pudendal nerve branch out after the alcox canal

Answer 36

inferior rectal nerve
perineal branch
dorsal nerve of the clitoris