3. Rectum
• Rectum = ?
• Straight in quadrupeds
• Not straight in man
• But curved in A-P & Side
to side.
• Misnomer
Straight
4. Rectum
• Lower dilated part of large
gut lies in pelvis
• B/w Sigmoid colon and Anal
canal
• Devoid of taenia coli,
sacculations, appendices
epiploicae and mesentery
5. Ano-rectal Junction
Rectum – Extent & Course
Begins as continuation of
sigmoid colon
Opposite S3
Ends at a point: 2-3cm in
front & little below tip of
coccyx
Lies at level of apex of
prostate
23. 3rd Valve
Most important &
constant
Anterior & Right wall
Along concavity of
middle lateral curve
Nelaton’s Sphincter
S5, 5cm above Anus
Divide rectum in to
upper & lower part
24. Upper Chamber
Pre-allantoic hind gut
May contain faeces
without reflex act of
defaecation
Lower Chamber
Endodermal Cloaca
Entry of faeces – Start
defaecation
27. • Support weight of faeces
• Prevent passage of
instrument
• Rectal washing should be
done in left lateral
position
• To prevent injury to
3rd valve
Importance of Valves
29. Arterial Supply Superior rectal artery
Posterior View
Continuation of IMA
Principal artery of
rectum
Entire mucosa and
upper musculature
Straight vessels arise
from plexus –
anastomose with
inferior rectal artery
30. Arterial Supply Middle rectal artery
Posterior View
Branch of Anterior
division of Internal
Iliac Artery
Supply lower part
31. Arterial Supply Inferior rectal artery
Posterior View
Branch of Internal
Pudendal Artery
Supply peri-anal skin
& Sphincter ani
32. Arterial Supply Median Sacral artery
Posterior View
Branch of Aorta
Supply posterior wall
of Ano-rectal
Junction
37. • Pelvic floor by Levator ani muscles
• Fascia of Waldeyer
• Lateral ligaments of the Rectum
• Rectovesical fascia of Denonvillers
• Pelvic peritoneum
• Perineal body with its muscles
• Pelvi-rectal & Ischio-rectal fat
Support of Rectum
39. Downwards & Backwards
Anal Canal – Extent & Course
Begins at ano-rectal jn
At a point 2-3cm in front &
little below tip of coccyx
Opens at anal orifice –
4cm below & in front of tip
of coccyx
Terminal part of Large Intestine
40. Anal Canal – Pecularities
• Ant wall shorter
• Surrounded by Sphincter
Ani
• Tone of it close the anal
canal
• Opens only during
defaecation
42. Relations
• Anteriorly: Perineal body
Males: membranous urethra
bulb of penis
Females: lower end of vagina
• Posteriorly: Anococcygeal ligament
Tip of coccyx
• Laterally: Ischiorectal fossae
• All round: Sphincteric muscles, tone of which keeps
the anal closed...
46. Interior of Anal Canal
Divided in to 3 parts
Pectinate Line
Hilton’s White Line
Upper area
Intermediate area / Pecten
Lower area / Anal Verge
47. Upper Muscular
part
• 15 mm
• Endodermal origin
• Lined by semitransparent
mucous membrane
– Simple columnar /
Stratified columnar or
squamous
• Plum red due to?
48. Upper Muscular
part - Features
Anal Columns /
Columns of Morgagni
Permanent longitudinal
mucosal folds
Contains Radicals of
Sup rectal veins
Reduplication of mucous
membrane
49. Upper Muscular
part - Features
Anal Valves / Valves of Ball
Crescentic mucosal folds
Connect lower ends of
anal columns
Pectinate Line / Dentate Line
Upper surface
Lower surface
Injury – Anal Fissure
50. Importance of Pectinate Line
Divide canal in to Upper &
Lower Areas
Development
Arterial Supply
Pectinate Line / Dentate Line
Venous Drainage
Lymphatic Drainage
Nerve Supply
85% diseases starts here
51. Upper Muscular
part - Features
Anal Papillae
Epithelial processes
Remnant of anal
membrane
52. Upper Muscular
part - Features
Anal Sinuses
Recesses above valves
between anal columns
Foreign body
53. Upper Muscular
part - Features
Anal Glands
Open in floor of sinuses
Infection - Fistula
54. Intermediate area /
Area of Pectane
• 15 mm
• Ectodermal origin
• Anal column: Absent
• Bluish pink appearance
of mucosa
• St sq epithelium
• No sweat / Sebaceous
gland
55. Lower area / Anal Verge
• 8 mm
• Ectodermal origin
• True skin with
pigmentation
• Corrugation due to
corrugator cutis ani
• Course hairs
56. Intermediate area /
Area of Pectane
• Color contrast between
Bluish pink mucosa above
& black skin below
• Lies at lower end of
internal anal sphincter
White line of Hilton
66. Clinical Anatomy
• Digital Per Rectal Examination
• Proctoscopy/Sigmoidoscopy
• Prolapse of Rectum
• Neurological disturbances of Rectum
• Rectal incontinence
• Carcinoma of Rectum
• Piles/Haemorrhoids
• Anal Fissure/Fissure in ano
• Fistula in ano
69. Internal hemorrhoids:
• Tributary of sup rectal
• Above white line
• Generally painless
External hemorrhoids:
• Tributary of inf rectal
• Below white line
• Generally painful
Hemorrhoids / Piles
78. Fistula in Ano
A fistula-in-ano is a hollow tract lined with granulation tissue
connecting a primary opening inside the anal canal to a
secondary opening in the perianal skin.
Secondary tracts may be multiple and from the same primary
opening.