Ischioanal Fossa and Pelvic Diaphragm Flashcards Preview

SF3-EXAM 4 (CAMELITA) > Ischioanal Fossa and Pelvic Diaphragm > Flashcards

Flashcards in Ischioanal Fossa and Pelvic Diaphragm Deck (51)
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What are the borders of the perineum?

Anteriorly- Pubic symphysis

Posteriorly- Coccyx

Laterally- Ischial tuberosity


The diamond shape of the perineum is best appreciated when the patient is in the _________ position.



What two structures separate the pelvic cavity from the perineum?

  • Urogenital diaphragm
    • Found in the urogenital triangle
  • Pelvic diaphragm
    • Found in the anal triangle 

NOTE: These two diaphragms are muscles and henceforth can be exercised and strengthened.


Between the 2 diaphragms is a fibrous block of tissue that serves as an attachment of the muscle found in the urogenital and pelvic diaphragm called the __________.

Perineal body

NOTE: In females it can be palpated between the vaginal orifice and the anus.


Function of the thoracoabdominal diaphragm

  • Support pelvic organs
  • Increase intra-abdominal/pelvic pressures upon contraction.

NOTE: The volume will decrease but the pressure will increase.


What are the two muscles of the pelvic diaphragm?

  • Levator ani
    • Pubococcygeus
    • Iliococcygeus
    • Puborectalis.
  • Coccygeus


What are the origins of the iliococcygeus muscle?

  • Tendinous arch of the obturator internus muscle
  • Inner part of the ischium


What two muscles originate from the tendinous arch?




The anorectal junction is kinked 80 degrees by the ________.

Puborectal sling

NOTE: The puborectal ring has a certain muscle tone and pulls the rectal-anal junction anteriorly producing a kink which helps to control defecation


Which two muscles make up the puborectal ring?


External anal sphincter

NOTE: Relaxation of the puborectal sling allows the rectum to straighten and the feces to drop down for defecation


Which muscle is most often town during childbirth?


NOTE: Tearing of the pubococcygeus results in fecal incontinence


What are the two types of episiotomy?

  • Median episiotomy
    • Take a scapel and run it from the vagina to about halfway to the anus.
  • Mediolateral episotomy
    • Run the scapel posteriorly and then move laterally to avoid the perineal body

NOTE: The purpose of an episiotomy is to make the opening of the birth canal larger. If this procedure is performed it is important to avoid cutting the levator ani. Cutting the levator ani will weaken the pelvic floor and make the woman more prone to fecal incontinence. 


What is the function of the broad ligament?

Serves as mesentery for the uterus, ovaries, and uterine tube


The ________ is subserous connective tissue that becomes thickened as the blood vessels come into the uterus and vagina. As it develops, it forms the cardinal ligament.

Endopelvic fascia

NOTE: The endopelvic fascia provides passive support but if this connective tissue becomes stretched becuase of childbith or lack of well developed pelvic muscles then you can't restore it.


What is the most important ligament of the uterus?

Transverse cervical fascia (cardinal ligament)

NOTE: This ligament comes infrom laterally around the blood vessels going to the uterus and vagina and it provides passive support that can be surgically tightened to raise the contents of the pelvic cavity.


The sigmoid colon enters the pelvic cavity and terminates as the _________.


NOTE: The rectum passes through the pelvic diaphragm and becomes the anal canal.


In a digital examination of the rectum of a male, doctor can palpate which three structures?

  • Prostate 
  • Seminal vesicle 
  • Bladder

NOTE:  The prostate is exam is to assess whether the prostate is hard or soft. It should be soft and smooth; if it is hard or lumpy that can be an indication of a tumor.


Only the (lower/upper) part of the rectum is covered by peritoneum.


NOTE: This part of the rectum is consider intraperitoneal. The terminal part of the rectum is extra-peritoneal and has no peritoneum and is beyond the serous membrane.


The ____________ is the lowest spot in the female's body where seroud fluid may be drained. 


The space between cervix and the posterior wall of the vagina is the _____________.

Posterior fornix

NOTE: The space betweeen the fornix and the pouch of Douglas is very thin. It is only peritoneum and the vaginal wall separating these two spaces so this a way a surgeon can gain access to the pelvic cavity either to drain fluid from ascites or infection or to inspect the ovaries.


What is one major physical differences between the sigmoid colon and rectum?

  • Teniae coli terminate at the rectum
  • The rectum has a complete outer coat of longitudinal muscle.



Tool used to inspect the pelvic cavity. The vaginal opening has to be widened and the scope goes through the posterior fornix so that the clinician can examine the ovaries and oviduct.


Which structure is most at risk for divertuclosis?

Sigmoid colon

NOTE: Diverticula do not form in the rectum. this is because the outer layer of the rectum is completely smooth muscle.


Where is the most common place for diverticula in the sigmoid colon?

Near the tenae coli, at locations where blood vessels enter the wall of the gut.

NOTE: One of the main reasons for divrticula is because as food passes through the large bowel, water is extracted and the feces become progressively harder. There are ridges in the feces that can punch holes into the mucosa



NOTE: The purpose of the semicircular folds is during the final stages of digestion the shelf-like folds help support the feces in the rectum and prevent them from falling out until the appropriate time. 


The ______ is very sensitive to stretch, so when feces enters, it initiates the feelings of defecation.



What are the boundaries of the ischioanal fossa?

  • Superiorly: Levator ani
  • Inferiorly: Skin
  • Laterally: Obturator internus and its fascia and the ischial tuberosity

NOTE: The center part of the ischioanal fossa is the rectum and anal canal


What are the contents of the ischioanal fossa?

  • Anus
  • Pudenal canal
    • Pudendal nerve
    • Internal pudenal artery and vein
  • Fat
    • Supports anus and allows the canal to expand during defecation
  • Iliococcygeus muscle

NOTE: The pudendal nerve has a branch coming off called the inferior rectal nerve that is going to go through the fat and innervate the external anal sphincter


How do the two anal sphincters differ?

  • Internal anal sphincter
    • Smooth muscle
    • Innervation: Pelvic splanchnic nerves
  • External anal spincter
    • Skeletal muscle
    • Innervation: Inferior rectal nerve of the pudendal nerve

NOTE: The function of the spinal cord in an unconscious person can be assessed by inserting a finger into the anus and testing the muscle tone of the sphincters


The pelvic splanchic nerves come off the sacral plexus at S2,3,4 because that is where the parasympathetic nervous system originates. These nerves join the ____________ and form the rectal plexus.

Inferior hypogastric plexus