Surgery Unit - 2, MMCH: Indoor Medical Officer
Surgery Unit - 2, MMCH: Indoor Medical Officer
Surgery Unit - 2, MMCH: Indoor Medical Officer
Nabarun Biswas
Indoor Medical Officer
Surgery Unit -2, MMCH
Anus & Anal Canal
• It is the
lowest part of
GIT that
begins at the
level where
the rectum
passes
through the
pelvic
diaphragm &
ends at the
anal verge
Embryology
Interior
Interior in detail
Musculature
Pubo-rectalis muscle
Sphincters of anus
Rectum
Location and peritoneal relations of
the rectum
S3
1 inch infront of
coccyx
Shape (flexures) of the rectum
- Antero-posterior curve
- 3 flexures
1. Upper concave to left
2. lower concave to left
3. Middle concave to right
Rectal ampulla
Anterior relations of the rectum
Posterior relations of the rectum
Arterial supply of ano-rectum
Venous
drainage
Hemorrhoids
Internal hemorrhoids
•Tributary of sup rectal
•Above dentet line
•Generally painless
External hemorrhoids
•Tributary of inf rectal
•Below white line
•Generally painful
11 o’clock
3 o’clock
7 o’clock
Lymphatic drainage of anus
Lymphatic drainage of rectum
Nerve supply of the anus
• Sympathetic L1-3
• Parasympathetic S2-4
• The hypogastric plexus
• Pelvic plexus
Nerve supply
Physiology of defecation