boundaries of perianal region or perirecatal region, division of perineum, contents of the division, anal region, urogenital region and their contents, perineal body, ischioanal fossa or ischio rectal fossa,boundaries of ischio anal fossa, contents of ischio rectal fossa, dimension of ischio anal fossa, recessess, anterior recesses, posterior recesses, spaces and canals, perianal space, ischioanal spaces, pudendal canal, superficial fascia, deep fascia. cutaneous innervation of urogenital region,

1. PERINEAL
REGION
Dr Sana Yaseen
Anatomy dept.

2. • Is lowest part of trunk.
• Has 2 openings in males:
Gastrointestinal system
Urinary system
• In females 3 openings:
Gastrointestinal
Genital
Urinary system
INTRODUCTION

3. BOUNDARIES
• Superficial boundaries
• Deep boundaries

4. SUPERFICIAL BOUNDARIES
ANTERIORLY
– External part of genitalia
POSTERIORLY
– Superior end intergluteal cleft
ON EACH SIDE:
– Upper part of medial side of thigh

5. DEEP BOUNDARIES
ANTERIORLY
– Pubic arch-upper part
– Arcuate/ inferior pubic ligament
POSTERIORLY:
– Tip of coccyx
EACH SIDE:
– Combine ischipubic rami
– Ischial tuberosity
– Sacrotuberous ligament

8. DIVISION OF PERINEUM
• Perineum is divided into two triangular
areas:
By transverse line joining anterior part of
ischial tuberosities, passing anterior to
anus.
 Anal region: posterior
 Urogenital region: anterior

9. contents
Anal region:
• Termination of anal canal(anus) in
median plan
• External, internal anal sphincters
• Ischio anal fossa on each side
Urogenital region: anterior
• Contains external urogenital organs
• Males: urethra enclosing roof of penis,
scrotum
• Females: genital organs

10. ANAL REGION
CUTANEOUS INNERVATION:
– Inferior rectal nerve S2-S4
– Perineal branch of 4th sacral nerve
SUPERFICIAL FASCIA:
– Ischioanal fossa containing fats and
connective tissue .
– Pudendal nerve
DEEP FASCIA:
Formed by inferior fascia of pelvic diaphragm &
fascia covering obturator internus

11. PERINEAL BODY:
• Is central part of perineum
• Is fibromuscular node situated in
median plane about 1.25cm in front
of anal margin.
• Ten muscles of perineum converge
here.

12. ISCHIOANAL FOSSA
• Is wedge shaped potential space
• Situation: each side of anal canal below
pelvic diaphragm
• Ischianal fossa formely known as
ischiorectal fossa
• Base is directed downward towards
surface, apex pointing upward

14. DIMENSIONS:
• Length (anteroposterior) : 5cm
• Width (side to side): 2.5cm
• Vertical depth: 5-6.2cm

15. BOUNDARIES:
Base: perianal skin
Apex: line where Obturator fascia meets
fascia of pelvic diaphragm / anal fascia
Anteriorly:
posterior border of perineal membrane
Posteriorly:
• Lower border of gluteus maximus
• Sacrotuberous ligament

16. Lateral wall (vertical)
• obturator internus
• Ischial tuberosity medial surface
Medial wall (upward & laterally)
• External anal sphincter ani externus
• Levator ani
• Anal fascia
Superiorly:
• Levator ani

17. Contents of ischioanal fossa
1. ISCHIORECTAL FAT
2. INFERIOR RECTAL NERVE &
VESSELS
3. PUDENDAL CANAL AND ITS
CONTENTS
4. POST. SCROTAL/ POST. LABIAL
NERVES & VESSELS
5. PERINEAL BRANCH OF S4 NERVE
6. CUTANEOUS BRANCHES OF S2, S3
NERVES.

18. RECESSES: extensions of fascia
• Anterior recesses
• Posterior recesses

19. • ANTERIOR RECESSES:
Formed by reflection of the fossa,
anteriorly with the urogenital diaphragm
• This recess is between pelvic diaphragm
(superior border) UG diaphragm (inferior
border)

21. POSTERIOR RECESS
• Is superior to the sacrotuberous
ligament, where it reflects on the
posterior part of the pelvic diaphragm
• It is inferior to the pelvic diaphragm

23. SPACES AND CANALS
Fascia in this regions forms spaces and
canal
• Perineal space:
• Ischioanal space:
• Pudendal canal:

24. Perianal space:
• Extends from white line of Hilton to
pudendal canal.
• Separates perianal space from
deep ischioanal space.
• Infection in this region is very
painful due to tension caused by
tight arangement of fat in this
region.

25. Ischioanal space:
• Is large and deep
• Fat is loosely arrange.
• Lunate fascia arches over
ischioanal fat.dividing it into two
parts
Suprategmental space above fascia
Tegmental space below fascia

28. Urogenital region
• CUTANEOUS INNERVATION:
• Dorsal nerve of penis or of clitoris
• Ilioinguinal nerve & genital branch
of genitofemoral nerve
• Perineal branch of post. Cutaneous
nerve of thigh
• Post. Scrotal / labial nerves
• Perineal branch of pudendal nerve

29. • PUDENDAL CANAL
Fascial canal in lateral wall of ischioanal
fossa enclosing pudendal nerve &
internal pudendal vessels.
The fascia of canal fuses with
Above: lunate fascia
Laterally: lower part of obturator fascia
Medially: perineal fascia
Below: falciform process of
sacrotuberous ligament.

31. SUPERFICIAL FASCIA:
• Made of two layers
• Superficial fatty layer, continuous with
superficial fascia of surrounding regions
• Deep membranous layer colles’ fascia

32. DEEP FASCIA
• Also known as perineal membrane
• Is thick
Urogenital region is divided into two
parts via perineal membrane
Above it: deep perineal space
Below it: superficial perineal space