Ischioanal fossa
Last revised by Travis Fahrenhorst-Jones on 2 Jul 2021
Citation, DOI, disclosures and article data
Citation:
Knipe H, Fahrenhorst-Jones T, Worsley C, et al. Ischioanal fossa. Reference article, Radiopaedia.org (Accessed on 04 Dec 2023) https://doi.org/10.53347/rID-26771
rID:
26771
Article created:
Disclosures:
At the time the article was created Henry Knipe had no recorded disclosures.
View Henry Knipe's current disclosuresLast revised:
2 Jul 2021, Travis Fahrenhorst-Jones ◉
Disclosures:
At the time the article was last revised Travis Fahrenhorst-Jones had no recorded disclosures.
View Travis Fahrenhorst-Jones's current disclosuresRevisions:
13 times, by 9 contributors - see full revision history and disclosures
Systems:
Sections:
Tags:
Synonyms:
- Ischiorectal fossa
- Ischiorectal fossae
- Ischioanal fossae
- Ischioanal fat
- Ischiorectal fat
The ischioanal (or ischiorectal) fossa is a fat-filled space of the perineum.
Gross anatomy
The ischioanal fossa is a paired triangular-shaped space lateral to the anal canal with an apex directed anteromedially towards the pubic symphysis. Each ischioanal fossa is separated from the other by the anococcygeal body, but they do still communicate superiorly to this and posterior to the anal canal.
Many textbooks and surgeons use the term ischiorectal fossa, however even a cursory review of the anatomy shows that the region is closely related to the anal canal, and not the rectum.
Boundaries
- roof: levator ani muscle
- floor: deep transverse perineal fascia
- medial wall: external anal sphincters/anal canal; levator ani muscle
- lateral wall: ischial tuberosity; obturator internus muscle; obturator fascia
- apex: intersection of the levator ani and obturator internus muscle
- base
- anteriorly: posterior border of the perineal body, urogenital diaphragm
- posteriorly: sacrotuberous ligament; gluteus maximus muscle
Contents
- ischioanal (or ischiorectal) fat pad
- pudendal canal: lies in a fibrous sheath on the lateral wall and itself contains the pudendal nerve and internal pudendal vessels
- inferior rectal branches of the pudendal nerve
- posterior scrotal/labial nerves and vessels
- perineal branch of S4
- perforating cutaneous nerve
- lymphatic trunks
Related pathology
References
- 1. McMinn. Last's anatomy, regional and applied. Churchill Livingstone. ISBN:044304662X. Read it at Google Books - Find it at Amazon
- 2. Schuenke M, Schulte E, Schumacher U et-al. General Anatomy and Musculoskeletal System. Thieme. (2010) ISBN:1604062924. Read it at Google Books - Find it at Amazon
- 3. Llauger J, Palmer J, Pérez C et-al. The normal and pathologic ischiorectal fossa at CT and MR imaging. Radiographics. 1998;18 (1): 61-82. doi:10.1148/radiographics.18.1.9460109 - Pubmed citation
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Articles:
- Dorsal nerve of penis or clitoris
- Pudendal canal
- Perineal branch of S4
- Perineal hernia
- Pudendal nerve
- Perianal fistula
- Anal triangle
- Inferior rectal artery
- Ischium
- Internal pudendal artery
- Urinary bladder hernia
- Inferior rectal nerve
- Perforating cutaneous nerve
- Urinary bladder
- Perineum
- Nerve to internal obturator and superior gemellus
Related articles: Anatomy: Abdominopelvic
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- spaces of the abdomen and pelvis
- anterior abdominal wall
- posterior abdominal wall
- abdominal cavity
- pelvic cavity
- perineum
- abdominal and pelvic viscera
- gastrointestinal tract
- spleen
- hepatobiliary system
-
endocrine system
-
adrenal gland
- adrenal vessels
- chromaffin cells
- variants
- pancreas
- organs of Zuckerkandl
-
adrenal gland
-
urinary system
-
kidney
- renal pelvis
- renal sinus
- avascular plane of Brodel
-
variants
- number
- fusion
- location
- shape
- ureter
- urinary bladder
- urethra
- embryology
-
kidney
- male reproductive system
-
female reproductive system
- vulva
- vagina
- uterus
- adnexa
- Fallopian tubes
- ovaries
- broad ligament (mnemonic)
- variant anatomy
- embryology
- blood supply of the abdomen and pelvis
- arteries
-
abdominal aorta
- inferior phrenic artery
- celiac artery
- superior mesenteric artery
- middle suprarenal artery
- renal artery (variant anatomy)
- gonadal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
- lumbar arteries
- median sacral artery
-
common iliac artery
- external iliac artery
-
internal iliac artery (mnemonic)
- anterior division
- umbilical artery
- superior vesical artery
- obturator artery
- vaginal artery
- inferior vesical artery
- uterine artery
- middle rectal artery
-
internal pudendal artery
- inferior rectal artery
-
perineal artery
- posterior scrotal artery
- transverse perineal artery
- artery to the bulb
- deep artery of the penis/clitoris
- dorsal artery of the penis/clitoris
- inferior gluteal artery
- posterior division (mnemonic)
- variant anatomy
- anterior division
-
abdominal aorta
- portal venous system
- veins
- anastomoses
- arterioarterial anastomoses
- portal-systemic venous collateral pathways
- watershed areas
- arteries
- lymphatics
- innervation of the abdomen and pelvis
- thoracic splanchnic nerves
- lumbar plexus
-
sacral plexus
- lumbosacral trunk
- sciatic nerve
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- perforating cutaneous nerve
- posterior femoral cutaneous nerve
- parasympathetic pelvic splanchnic nerves
- pudendal nerve
- nerve to quadratus femoris and inferior gemellus muscles
- nerve to internal obturator and superior gemellus muscles
- autonomic ganglia and plexuses
