Download MBBS Rectum and Anal Canal Lecture PPT

RECTUM & ANAL CANAL


Anal triangle(Posterior Perineum)

--- Content provided by FirstRanker.com ---

Posterior part of

perineum

--- Content provided by FirstRanker.com ---

Boundaries:

Anteriorly: imaginary

line joining two ischial

--- Content provided by FirstRanker.com ---

Tuberosities.

POSTEROLATERALLY:

--- Content provided by FirstRanker.com ---

sacrotuberous

ligament

--- Content provided by FirstRanker.com ---

Ischioanal (ischiorectal) fossa:

A perineal space on both side of anal canal.

Wedge shaped with apex directed upwards.

--- Content provided by FirstRanker.com ---

Lateral wall vertical and medial wall sloping downward and medially.

Fat filled: allows expansion of rectum and anal canal during

--- Content provided by FirstRanker.com ---

defecation.


Ischioanal (ischiorectal) fossa:

--- Content provided by FirstRanker.com ---

Measurements:

Vertical- 5cm

Anteroposterior- 5cm

--- Content provided by FirstRanker.com ---

Transverse- 2.5cm


Ischioanal (ischiorectal) fossa:

--- Content provided by FirstRanker.com ---

Boundaries

Laterally : obturator internus

--- Content provided by FirstRanker.com ---

and its fascia & ischial

tuberosity

Medially: levator ani covered by

--- Content provided by FirstRanker.com ---

anal fascia & external anal

sphincter

--- Content provided by FirstRanker.com ---

Anteriorly: superficial and deep

transverse perineal muscles.

Posteriorly: sacrotuberous

--- Content provided by FirstRanker.com ---

ligament covered by Gluteus

Maximus

--- Content provided by FirstRanker.com ---

Apex: fusion of obturator and

anal fascia

Base: skin and superficial fascia

--- Content provided by FirstRanker.com ---

Ischioanal (ischiorectal) fossa:

Lunate fascia:

--- Content provided by FirstRanker.com ---

Arched fascia in ischiorectal

fossa.

--- Content provided by FirstRanker.com ---

Starts from the periosteum

of ischial tuberosity makes

medial wall of pudendal

--- Content provided by FirstRanker.com ---

canal, lines obturator fascia

goes towards apex and

--- Content provided by FirstRanker.com ---

lines anal fascia blends with

it at the level of white line of

Hilton.

--- Content provided by FirstRanker.com ---

Summit of this facia called

tegmentum.

--- Content provided by FirstRanker.com ---

Pudendal or Alcock's canal:

Fascial tunnel in lateral

--- Content provided by FirstRanker.com ---

wall of ischiorectal fossa

2.5cm above ischial

tuberosity.

--- Content provided by FirstRanker.com ---

Formed either by

splitting of obturator

--- Content provided by FirstRanker.com ---

fascia or by separation

between lunate and

obturator fascia or by

--- Content provided by FirstRanker.com ---

splitting of perianal

fascia.

--- Content provided by FirstRanker.com ---

Pudendal or Alcock's canal:

?Extends from lesser sciatic foramen to posterior limit of deep perineal

--- Content provided by FirstRanker.com ---

space.

?contents: internal pudendal vessels & pudendal nerve

and its 2 branches- dorsal nerve of penis/clitoris and

--- Content provided by FirstRanker.com ---

perineal nerve.


Parts of ischiorectal fossa:

--- Content provided by FirstRanker.com ---

Suprategmental:

above lunate fascia

--- Content provided by FirstRanker.com ---

contains loose fat.

Ischiorectal space

proper: between

--- Content provided by FirstRanker.com ---

lunate and perianal

fascia. Contain fat

--- Content provided by FirstRanker.com ---

with fibrous tissue.

Perianal space:

between perianal

--- Content provided by FirstRanker.com ---

fascia and skin.

Contains loculated fat

--- Content provided by FirstRanker.com ---

in tight fibroelastic

compartments.
Contents

--- Content provided by FirstRanker.com ---

?Internal pudendal vessels and pudendal

nerve

?Inferior rectal vessels and nerve

--- Content provided by FirstRanker.com ---

?Posterior scrotal/labial vessels and nerves

?Perineal branch of 4th and perforating

--- Content provided by FirstRanker.com ---

branch of 2nd and 3rd sacral nerve.

?Fat pad.

--- Content provided by FirstRanker.com ---

APPLIED ANATOMY

Ischiorectal abscess:

loose fat so an abscess in

--- Content provided by FirstRanker.com ---

this region may grow to a

large size before

--- Content provided by FirstRanker.com ---

producing pain.

Perianal abscess: fat is in

tight compartments so

--- Content provided by FirstRanker.com ---

the abscess is very

painful due to tension

--- Content provided by FirstRanker.com ---

caused by building pus.

Abscess bursting in the

anal canal may produce

--- Content provided by FirstRanker.com ---

fistula in ano.


APPLIED ANATOMY

--- Content provided by FirstRanker.com ---

Pudendal block: for perineal anesthesia.

Generally done in 2nd stage of labour to perform or repair

--- Content provided by FirstRanker.com ---

episiotomy.

Transvaginal and Transperineal approach.
RECTUM

--- Content provided by FirstRanker.com ---

LARGE INTESTINE
LARGE INTESTINE

3 unique features:

--- Content provided by FirstRanker.com ---

? Teniae coli ? Three bands of longitudinal smooth muscle.

?Haustrations ? Pocket like sacs caused by tone of teniae coli.

--- Content provided by FirstRanker.com ---

?Epiploic appendages ? Fat-filled pouches of visceral

peritoneum.

? Subdivided into Caecum, Appendix, Colon, Rectum &

--- Content provided by FirstRanker.com ---

?Anal canal


Rectum

--- Content provided by FirstRanker.com ---

? Introduction

? Extent

? Course &

--- Content provided by FirstRanker.com ---

directions

? Relations

--- Content provided by FirstRanker.com ---

? Mucosal folds

? Blood & nerve

supply

--- Content provided by FirstRanker.com ---

? Supports

? Applied

--- Content provided by FirstRanker.com ---

anatomy
INTRODUCTION

Terminal part of large intestine before anal canal.

--- Content provided by FirstRanker.com ---

? Cardinal features of large intestine ? absent

?Length ? 12 cm

?Diameter ? upper part 4 cm, lower part dilated as rectal

--- Content provided by FirstRanker.com ---

ampulla

? Curved in both sagittal and coronal planes

--- Content provided by FirstRanker.com ---

? Function ? temporary storage of fecal matter;distension

causes desire to defecate

--- Content provided by FirstRanker.com ---

Extent

?Begins at S3, lower

end of sigmoid

--- Content provided by FirstRanker.com ---

mesocolon ?

recto-sigmoid

--- Content provided by FirstRanker.com ---

junction.

?Ends slightly below

and 2- 3 cm in front

--- Content provided by FirstRanker.com ---

of tip of coccyx ?

anorectal junction.

--- Content provided by FirstRanker.com ---

? Males ? at level of

apex of prostate.

--- Content provided by FirstRanker.com ---

Course and directions

? Beginning and end lie in median plane

? 2 AP curvatures

--- Content provided by FirstRanker.com ---

? Sacral flexure ? follows curvature of sacrum and coccyx

? Perineal flexure ? backward bend in anorectal junction

--- Content provided by FirstRanker.com ---

? 3 lateral curvatures

? Upper ? convex to right

? Middle ? convex to left

--- Content provided by FirstRanker.com ---

? most prominent

? Lower ? convex to right

--- Content provided by FirstRanker.com ---

Peritoneal relations

? Upper 1/3 ? in front and sides

--- Content provided by FirstRanker.com ---

? Middle 1/3 ? only in front

? Lower 1/3 ? devoid of peritoneum

? Dilated to form ampulla

--- Content provided by FirstRanker.com ---

? Below rectovesical pouch in males

? Below recto uterine pouch in females

--- Content provided by FirstRanker.com ---

Visceral relations

? Anteriorly - in males

--- Content provided by FirstRanker.com ---

? Upper 2/3 ?

rectovesical

pouch with coils of

--- Content provided by FirstRanker.com ---

Intestine

? Lower 1/3 ? base of

--- Content provided by FirstRanker.com ---

urinary bladder, ureters,

seminal vesicle, vas and

prostate

--- Content provided by FirstRanker.com ---

Visceral relations

? Anteriorly in females

--- Content provided by FirstRanker.com ---

? Upper 2/3 ? recto- uterine pouch with coils of intestine and sigmoid

colon, pouch separates the rectum from uterus and upper part of vagina

--- Content provided by FirstRanker.com ---

? Lower 1/3 ? lower part of vagina
Visceral relations

? Posterior in both sexes.

--- Content provided by FirstRanker.com ---

? Lower 3 sacrum, coccyx and anococcygeal ligament

? Piriformis, coccugeus and levator ani

? Median sacral, sup rectal and lower lat sacral vessels

--- Content provided by FirstRanker.com ---

? Sympathetic chain with ganglion impar, ant primary rami of S3-5, Co1,

and pelvic splanchnic nerves

--- Content provided by FirstRanker.com ---

? Lymph nodes, lymphatics and fat


POST. RELATIONS

--- Content provided by FirstRanker.com ---

Mucosal folds

? 2 types of folds

--- Content provided by FirstRanker.com ---

? Longitudinal ? temporary, in lower part, disappear on distension

? Transverse / Houston's valves ? permanent

--- Content provided by FirstRanker.com ---

INTERIOR OF RECTUM: MUCOSAL

FOLDS

--- Content provided by FirstRanker.com ---

TRANSVERSE MUCOSAL FOLDS


Blood supply

--- Content provided by FirstRanker.com ---

Venous drainage


Lymphatic drainage

--- Content provided by FirstRanker.com ---

? Upper ? - sup

rectal vessels ->

--- Content provided by FirstRanker.com ---

para rectal &

sigmoid nodes ->

inf mesenteric

--- Content provided by FirstRanker.com ---

nodes

? Lower ? - middle

--- Content provided by FirstRanker.com ---

rectal vessels ->

internal iliac nodes
Nerve supply

--- Content provided by FirstRanker.com ---

? Sympathetic ? L 1-2

? Parasympathetic ? S 2-4

? Distension ? Parasympathetic

--- Content provided by FirstRanker.com ---

? Pain - both
Supports

? Pelvic floor by levator ani

--- Content provided by FirstRanker.com ---

? Waldeyer's fascia ? lower part of rectal ampulla to sacrum,

contain sup rectal vessels and Lymphatics

--- Content provided by FirstRanker.com ---

? Lateral ligaments ? contain middle rectal vessels, nerves

? Rectovesical pouch

? Pelvic peritoneum

--- Content provided by FirstRanker.com ---

? Perineal body
APPLIED ANATOMY

?PR EXAM

--- Content provided by FirstRanker.com ---

? PROCTOSCOPY

? RADIOLOGICAL STUDIES

--- Content provided by FirstRanker.com ---

? PROLAPSE AND

INTUSUCEPTION

? POLYP

--- Content provided by FirstRanker.com ---

? CARCINOMA

--- Content provided by FirstRanker.com ---

ANAL CANAL


INTRODUCTION

--- Content provided by FirstRanker.com ---

?Terminal part of alimentary

tract,begins at ano-rectal junction.

--- Content provided by FirstRanker.com ---

?Rectal ampulla suddenly narrows at

ano-rectal junction 2-3 cms infront

and slightly below tip of coccyx.

--- Content provided by FirstRanker.com ---

?From ano-rectal junction canal

passes downwards & backwards

--- Content provided by FirstRanker.com ---

through Pelvic diaphragm.

?Opens at anal orifice situated in the

cleft between buttocks 4 cms below

--- Content provided by FirstRanker.com ---

& in front of tip of coccyx.

--- Content provided by FirstRanker.com ---

Ano-rectal junction in male

corresponds to apex of prostate

4 cms in front of tip of coccyx

--- Content provided by FirstRanker.com ---

Features

Anterior wall shorter than posterior wall

--- Content provided by FirstRanker.com ---

Surrounded by sphincter ani muscles

Canal closed except during defaecation

--- Content provided by FirstRanker.com ---

Measurements

Length (adult) 3.8 cms

Breadth when empty

--- Content provided by FirstRanker.com ---

lateral walls approximated

(antero-posterior slit)

--- Content provided by FirstRanker.com ---

RELATIONS

In front:

--- Content provided by FirstRanker.com ---

1. Perineal body

2. In male ? bulb of penis & spongy

urethra

--- Content provided by FirstRanker.com ---

In female ? Lower part of post. wall

of vagina

--- Content provided by FirstRanker.com ---

Behind:

Ano-coccygeal raphe

Fibro-fatty tissue bet' peri-anal skin

--- Content provided by FirstRanker.com ---

& raphe

On each side:

--- Content provided by FirstRanker.com ---

Ischio-rectal fossa and

its contents

--- Content provided by FirstRanker.com ---

INTERIOR OF ANAL CANAL

Divided by pectineal line &

Hilton's line into 3 areas

--- Content provided by FirstRanker.com ---

1. Upper (15 mm)

2. Intermediate (15 mm)

--- Content provided by FirstRanker.com ---

3. Lower (8 mm)

(Anal verge)

--- Content provided by FirstRanker.com ---

FEATURES IN THE UPPER PART OF ANAL CANAL

1. Anal columns (columns of Morgagni):

These are permanent longitudinal mucous

--- Content provided by FirstRanker.com ---

folds numbering 6 to 10. They contain

radicles of the superior rectal vein.

--- Content provided by FirstRanker.com ---

2. Anal valves (valves of Morgagni): These

are crescentic folds ofmucousmembrane

which connect the lower

--- Content provided by FirstRanker.com ---

ends of adjacent anal columns. The free

margins of thesevalves are directed upward.

The position of these valves is indicated by

--- Content provided by FirstRanker.com ---

the wavy pectinate line (also calleddentate

line).

--- Content provided by FirstRanker.com ---

3. Anal sinuses: These are vertical recesses

between the anal columns and above the anal

valves. The ducts of tubularanal glands

--- Content provided by FirstRanker.com ---

present in the submucosa open in the floor

of anal sinuses.
FEATURES IN THE LOWER PART OF ANAL CANAL

--- Content provided by FirstRanker.com ---

(a) Upper region (often called pecten): It is

15 mm long and extends from the pectinate

--- Content provided by FirstRanker.com ---

line to Hilton's line. It is lined by the non-

keratinized stratified squamous epithelium.

The mucous lining in this region appears

--- Content provided by FirstRanker.com ---

bluish in colour due to underlying dense

venous plexus and is adherent to the

--- Content provided by FirstRanker.com ---

underlying structures.

(b) Lower region of lower anal canal: It is

about 8 mm in extent and lined by the true

--- Content provided by FirstRanker.com ---

skin containing sweat and sebaceous gland.

It shows pigmentation. In adult males,

--- Content provided by FirstRanker.com ---

coarse hairs are often found around the anal

orifice.

--- Content provided by FirstRanker.com ---

PECTINATE LINE
?Muco-cutaneous junction of

anal canal

--- Content provided by FirstRanker.com ---

?Corresponds with position of

anal valves

--- Content provided by FirstRanker.com ---

?Situated at the middle of

internal sphincter

?Divides anal canal into upper

--- Content provided by FirstRanker.com ---

and lower areas (proctodeum)

which are different in

--- Content provided by FirstRanker.com ---

development, blood supply,

lymphdrainage and in nerve

supply

--- Content provided by FirstRanker.com ---

HILTON'S LINE

It is a color contrast bet'

--- Content provided by FirstRanker.com ---

bluish pink area above and

black skin below

The line is represented by

--- Content provided by FirstRanker.com ---

inter-sphincteric groove at

the lower end of the internal

--- Content provided by FirstRanker.com ---

sphincter

Indicates lower end of

internal sphincter

--- Content provided by FirstRanker.com ---

SPHINCTERS OF THE ANAL CANAL

Two ? Internal & external, surround the anal canal.

--- Content provided by FirstRanker.com ---

SPHINCTER ANI INTERNUS

Involuntary sphincter,Thickening of circular muscle of lower part of rectum

--- Content provided by FirstRanker.com ---

Surrounds upper 3/4th of anal canal

Lower end corresponds with Hilton's line

Middle corresponds with pectinate line

--- Content provided by FirstRanker.com ---

Internally the sphin. Is separated from mucous membrane by internal venous plexus

Externally separated from ext. sphin.Muscle by Conjoint sheath derived from levator

--- Content provided by FirstRanker.com ---

ani and longitudinal muscles of rectum


SPHINCTER ANI EXTERNUS

--- Content provided by FirstRanker.com ---

Voluntary sphincter

Surrounds entire length of anal canal

Consists of 3 parts ? Subcuatneous,Superficial & Deep

--- Content provided by FirstRanker.com ---

Nerve Supply of Sphincter

1. The internal sphincter is made up of smooth muscle and

supplied by the autonomic nerve fibres (sympathetic and

--- Content provided by FirstRanker.com ---

parasympathetic), hence it is involuntary.

2. The external anal sphincter is made up of striated muscle

--- Content provided by FirstRanker.com ---

and hence, supplied by the somatic nerve--inferior rectal

nerve and perineal branch of 4th sacral nerve. It is

therefore under voluntary control.

--- Content provided by FirstRanker.com ---

CONJOINT FIBRO ? ELASTIC SHEATH

Formed by longitudinal muscle of rectum blending at ano-

--- Content provided by FirstRanker.com ---

rectal Junction with puborectalis part of leavtor ani


BLOOD SUPPLY

--- Content provided by FirstRanker.com ---

VENOUS DRAINAGE

--- Content provided by FirstRanker.com ---

LYMPHATIC DRAINAGE


APPLIED ANATOMY

--- Content provided by FirstRanker.com ---

Fibrous tracts communicating with two

surfaces Ano-rectal mucosa and skin

--- Content provided by FirstRanker.com ---

Normal Veins Internal & external haemorrhoids



Sentinal pile is a tag formed

--- Content provided by FirstRanker.com ---

by a ruptured anal valve


PR - Per rectal examination

--- Content provided by FirstRanker.com ---

THANK U