Large Intestines, Rectum and Anal Canal Flashcards
1
Q
At what level does the Rectum begin?
A
S 3
2
Q
Fill in the blanks. In the rectum , there are three sickle-shaped transverse rectal folds, formerly called _____.
A
Rectal Valves of Houston
3
Q
Which rectal valve is the largest?
A
Middle rectal valve
4
Q
How long is the rectum?
A
12 cm long ( 5 inches)
5
Q
What is the blood supply of the Rectum?
A
Superior rectal artery
Middle rectal artery
Inferior rectal artery
Median sacral artery
6
Q
True or False? All of the rectum is covered in Peritoneum .
A
FALSE!! The Lower 1/3 of the rectum is not covered in Peritoneum
7
Q
Where does the rectum begin and end?
A
1)Commences at Rectosigmoid junction anterior to the body of S3.
2) Ends about 2-3 cm in front and slightly below the tip of the coccyx as it passes through the pelvic diaphragm.
8
Q
What is the name of the lower extent of peritoneum in males and where is it located ?
A
Pouch of Proust - 7.5 cm from the anus
9
Q
What is the name of the lower extent of peritoneum in females and where is it located ?
A
( Rectouterine pouch of Douglas ) is about 5.5 cm above the anus or 7.5 cm above the external orifice of the Vagina.
10
Q
Where does the middle curve of Rectum occur?
A
It occurs at the upper border of the coccyx.
11
Q
What are the HORIZONTAL / TRANSVERSE RECTAL VALVES OF HOUSTON made of?
A
Mucosa, submucosa and a thickening of the inner circular muscle.
12
Q
How long is the anal canal?
A
About 2.5 to 5.0 cm – usually around 3.8 cm in length*.
13
Q
What is the name of the structure at the ends the anal sinuses?
A
Anal glands ( of Ball )
14
Q
What is the name of the structure which the iliocaecal junction is guarded by?
A
Iliocaecal valve - whose almost transverse lips may help to prevent some reflux into the ileum,
15
Q
Where is the caecum normally found?
A
The caecum lies on the peritoneal floor of the right iliac fossa, over the iliacus and psoas fasciae and the femoral and lateral femoral cutaneous nerves. Its lower end lies at the pelvic brim.
16
Q
What is the blood supply of the caecum?
A
Branches of the anterior and posterior caecal arteries which fan out over the respective surfaces of the caecum.
17
Q
What is the anterior and posterior caecal arteries a branch of?
A
Ileocolic artery
18
Q
What is the length of the normal appendix?
A
6–9cm
19
Q
What is the most common position of the appendix?
A
Retrocoecal position- behind the cecum
20
Q
What is the name of the small fold of peritoneum which extends from the terminal ileum to the front of the mesoappendix?
A
Inferior ileocaecal fold (or ‘bloodless fold of Treves’)
21
Q
What is the name of the space between the Ileocaecal fold and the meso appendix?
A
Inferior ileocaecal recess
22
Q
What is the blood supply to the Appendix?
A
The appendicular artery is normally a branch of the inferior division of the ileocolic artery (lodenquai says posterior caecal artery)
23
Q
Fill in the blanks. “Exposure of the appendix during appendicectomy is through a _____________.”
A
McBurney or transverse muscle-splitting incision
24
Q
Which parts of the large intestines are suspended in mesenteries?
A
The transverse colon and sigmoid colon.
25
How long is the Ascending Colon and where does it extend from?
15 cm - It extends upwards from the ileocaecal junction to the right colic (hepatic) flexure.
26
Where is the Caecum developed from?
From the caecal bud arising from the caudal limb of the primitive intestinal loop
27
How long is the Transverse colon?
50 cm long
28
How long is the descending colon?
25cm
29
Where is the splenic flexure located?
The splenic flexure lies on the lateral surface of the left kidney, below and in contact with the tail of the pancreas and the spleen.
30
Where is the phrenicocolic ligament located and what structures does it connect to?
It attaches the splenic flexure to the diaphragm at the level of the tenth and eleventh ribs.
31
Mobilization of the descending colon is conveniently carried out by dividing the peritoneum along what structure?
White line of Toldts
32
Where is the weakest link in marginal chain of vessels?
It is near the left colic flexure, between the middle and left colic branches, i.e. between midgut and hindgut vessels.
33
What is the blood supply to the colon?
The ascending colon and the proximal two-thirds of the transverse colon are supplied by the ileocolic, right colic and middle colic branches of the superior mesenteric artery, and the remainder of the colon by the left colic and sigmoid branches of the inferior mesenteric.
34
What is the nerve supply for the large intestines?
Parasympathetic supply- partly from the vagi and partly from the pelvic splanchnic nerves.
Sympathetic supply - derived from spinal cord segments T10–L2.
35
What are the three components of Tinaei Coli?
Teniae libera - ( Anterior)
Teniae Mesocolica - (Posteromedial)
Teniae Omentalis - (Posterolateral)
36
What is Lemmel's syndrome ?
Lemmel syndrome is a rare clinical entity characterized by the presence of a periampullary duodenal diverticulum resulting in compression and dilatation of the pancreatic and common bile ducts, accompanied by obstructive jaundice.
37
Where does the root of the mesentery (of the small intestine) extend from?
The root of proper mesentery extends 15 cm from duodenojejunal flexure at the level of left side of L2, obliquely (toward inferior right) to the ileocecal junction in the right iliac fossa at the level of right sacroiliac joint.
38
What is the name of the lower dilated portion of the rectum?
Rectal Ampulla
39
What planes are the rectum present in ?
Anteroposterior and lateral planes
40
To what structures does the concavity of the Sacral curvature corresponds to?
The concavity of the sacrum and coccyx.
41
To what structures does the perineal curvature corresponds?
Corresponds to the forward bend of the anorectal junction.
42
Which lateral curvature of the rectum is convex to the left ?
Middle lateral curvature
43
Where is the upper lateral curvature located from?
It is convex to the right at the junction of S3, S4 vertebrae.
44
Where is the middle lateral curvature located?
It is convex to the left at the sacrococcygeal junction. It is the most prominent curvature.
45
Where is the lower lateral curvature located?
It is convex to the right at the level
of tip of the coccyx.
46
What part of the middle one third of the rectum is covered in peritoneum ?
Only the front ( anterior portion)
47
What is the anterior relations for the upper and lower third of the rectum in females?
Upper two third - Rectouterine pouch of Douglas, coils of the small intestine and the sigmoid colon.
Lower one third - Vagina ( lower part )
48
What is the anterior relations of the upper and lower third of the rectum in males?
Upper 2/3 - Rectovesicle pouch of Proust, coils of the small intestine and sigmoid colon.
Lower 1/3 -
* Base of the urinary bladder
* Ureters (terminal parts)
* Seminal vesicles
* Ampullae of vas deferens
* Prostate
49
What is the name of the structure that separates the rectum from the Base of the urinary bladder, Ureters (terminalparts), Seminalvesicles, Ampullae of vas deferens & Prostate
Rectovesical fascia of Denonvilliers
50
What is the name of the structure that separates the rectum from the lower part of the vagina?
Ill-defined rectovaginal fascia
51
Which valve of Houston is the largest?
Third valve
52
What is the arterial supply of the rectum?
Superior rectal artery - continuation of Inferior mesenteric artery
Middle rectal artery - branch of anterior division of internal iliac artery
Inferior rectal artery - branch of pudendal artery.
Median sacral artery - branch of abdominal aorta
53
Where does the superior rectal artery becomes a continuation of the inferior mesenteric artery?
At the pelvic brim
54
Where does the branches of the superior rectal artery anastomose with the branches of the inferior rectal artery?
At the pectinate line
55
What is the venous drainage of the rectum?
Superior rectal vein
Middle rectal veins (two in number)
Inferior rectal veins (two in number)
56
Where do the rectal veins originates from?
Internal and external venous plexuses of the rectum and anal canal.
57
Where is the internal venous plexus located?
It is present in the sub mucous coat and surrounds the anal canal above the Hilton's line.
58
Where is the external venous plexus located?
Present between the perianal skin and the subcutaneous part of the external anal sphincter.
59
Fill in the blanks." The lower part of the rectum and the anal canal are surrounded by a venous plexus called __________."
Annulus hemorrhoidalis.
60
Which vein does the Superior rectal vein drain into?
Superior rectal drain will continue as the inferior mesenteric vein and drain into the splenic vein.
61
Which drain will the Middle and Inferior rectal veins drain into?
Middle will drain into Internal iliac vein
Inferior rectal vein will drain into the internal pudendal vein
62
True or False? Lymphatics from the upper half of the rectum drain into the internal iliac nodes while lymphatics from the lower half of the rectum drain into the inferior mesenteric nodes.
FALSE!!! Lymphatics from upper half drain into inferior mesenteric nodes while lymphatics from the lower half drains into internal iliac nodes.
63
What is the innervation of the rectum?
Sympathetic fibres - L1, L2 segments of spinal cord (superior and inferior hypogastric plexuses)
Parasympathetic fibres - S2, S3, S4 segments of spinal cord (Pelvic splanchnic nerve)
64
In the upper part of the Anal Canal, there are about 6-10 permanent longitudinal folds formed by a suplication of mucosa , what is the name of these folds?
Anal Columns of Morgagni
65
What structures are found in the anal columns of Morgagni?
Superior rectal vessels
Internal rectal Venous plexus
AV shunt of Haller
" SIA - I'm gonna swing from the anal columnsss"
66
Fill in the blanks. " In between the columns are the _______ and they contain ________ that end on the floor of this structure.
Anal sinuses and they contain Anal glands of Ball which end on the floor of these sinuse.
67
What type of epithelium is found in the Anal Sinuses?
Simple columnar with Goblet cells.
68
The crescentic mucosal folds connecting the lower ends of the anal columns is called ?
Anal valves
69
Fill in the blanks. "The lower surface of the anal valves is lined by ____________ epithelium.
Stratified Squamous epithelium
70
True or False? In the anal canal , above the pectinate line the nerve supply is Somatic while below the pectinate line is Autonomic .
FALSE!! Above pectinate line is Autonomic ( A for above A for autonomic)
Below pectinate line is Somatic
71
What is the Epithelium in the Lower part of the Anal canal ( below the pectinate line)?
Stratified squamous non keratinised without sebaceous or sweat glands
72
What is the name of the structure that separates the anal canal into a upper and lower region?
Pectinate or Dentate line
73
What is the blood supply to the Lower anal canal?
Inferior rectal artery
74
What is the blood supply to the Upper anal canal?
Superior Rectal Artery
75
What is the lymph drainage of the Upper anal canal vs the lower anal canal?
Upper Anal Canal - Internal Iliac nodes, common iliac & inferior mesenteric lymph nodes .
"Up goes in "
Lower anal canal- Superficial inguinal lymph nodes
76
True or False? The upper anal canal is embryologically derived from endoderm of the hind gut while the lower anal canal is embryologically derived from ectoderm of proctodeum.
TRUE!!
77
What is the nerve supply of the Internal Anal Sphincter?
Automatic nerve supply- inferior hypogastric plexus
78
By what structure is the Internal Anal sphincter formed from?
Thickened circular muscle coat of the anal canal and ends distally at the Intersphincteric groove
79
What are the parts of the External Sphincter of Anal canal?
Deep part
Superficial part
Subcutaneous Part
80
What are the anterior relations in the male for the upper two thirds of the rectum?
Sigmoid colon
Coils of small intestines(ileum)
Retrovesical Pouch of Prousts
81
What are the anterior relations in the male for the Lower one thirds of the rectum?
- Base of the urinary bladder
- Ampulla of Vas deferens
- Denonviller's fascia
- Prostate
- Ureter
- Seminal vesicles
82
What is the anterior relation of the Anal Canal in Males?
Perioneal body
Bulb of the penis + spongy urethra
83
What are the Posterior relations for the Rectum in Male & Females?
Great - Ganglion Impar
Cool - Coccyx & Coccygeus
Wet - Waldyer's fascia + lymphatics + fat
P - Pelvic Splanchnic nerves
P- Piriformis
A - Anterior Primary Rami of S2 to Co1
A- Anococcygeal raphe (distally)
L- Lower 3 pieces of sacrum
L- Lateral Sacral vessels
L- Levator Ani
M - Median sacral artery
S- Superior rectal artery
S- Sympathetic trunk
"Posterior rectum has Great Cool Wet Ppaalllmss"
84
What is the anatomical composition of Demonvillier's fascia ?
Retroprostatic fascia + Prerectal fascia
85
What is the space between Denonvillier's fascia and what is located inside of it?
Denonvillier's space - loose connective tissue is located in it
86
Fill in the blanks. " Denonvillier's fascia is developed from ______."
Urorectal septum
87
What are the anterior relations for the upper two thirds of rectum in females?
Rectouterine Pouch of Douglas
Sigmoid colon
Coils of intestines( ileum)
88
What are the anterior relations for the lower 1/3 of the rectum in females?
Posterior wall of vagina
Perineal Body
89
What are the three sites of Primary piles (haemorrhoids?
AV shunts from in the Anal columns drain into radicles of the superior rectal veins at position 3, 7 & 11.
90
What is the Parasympathetic innervation of the rectum and anal canal?
Pelvic splanchnic nerves S2 - S4
91
What is the Sympathetic innervation of the rectum and anal canal ?
Superior and Inferior Hypogastric Plexuses ( inferior goes to lower part of reactum and internal anal sphincter)
92
What is the sensory nerve supply to the lower part of the rectum ( below the pectinate line)?
Inferior Rectal Nerve - A branch of the Pudendal nerve
93
What are the structures that support the rectum?
* Puborectal sling of the Levator Ani muscle
* Pelvic floor
* Pelvi-rectal and ischiorectal fat
* Fascia of Waldeyer
* Fascia of Denonvilliers
94
Fill in the blank. " The fascia of Waldeyer attaches the rectum to ________."
The Sacrum
95
Which rule is applied to the examination of anal fistula?
Goodsall's rule .
96
What does Goodwill's rule state?
It states that of the external opening of the fistula lies POSTERIOR to a line drawn from 9 o'clock to 3 o'clock then it tracks AROUND the anus laterally and opens into the midline posteriorly.
But if the external opening of the fistula is ANTERIOR to this line then it opens directly into the anal canal.
97
What is the name of the structure which separates the upper right lateral curvature of the rectum from the from the lower right lateral curvature (LRC)?
Middle valve of Houston
98
Which valve of Houston is located on the right side of rectum?
Middle Valve
( Upper and Lower are to the left to the left)
99
What are the structures contained in the Posterior Anal Triangle?
Anal canal
Ischiorectal (ischioanal) fossa
Pudendal canal.
100
What is the name of the raphe that runs from coccyx to junction of rectum and anus at perineal flexure?
Annococcygeal raphe ( aka levator plate or postanal plate).
101
Where does the Pubococcygeus and Iliococcygeus arise from?
Pubococcygeus arises from posterior pubic bone.
Illiococcygeus arises from a tendinous arch in superior fascia of obturator internus.
102
Where does the annococcygeal ligament run from?
This runs from tip of coccyx to the middle third of external anal sphincter.
103
What is the name given to the thickening at the end of anal columns of Morgagni?
Papilla
104
The gastrocolic trunk of Henle is a large vein formed from which other veins?
It is formed from middle colic vein, right gastro epiploic vein and inferior anterior pancreaticoduodenal vein.
105
What is the attachment of the transverse mesocolon?
Tt runs from inferior pole of right kidney across anterior aspect of 2nd part of duodenum, head and body of pancreas then to inferior pole of left kidney.
106
What is the sequential order of lymphatic spread in gastrointestinal malignancy?
First to epicolic nodes, then to paracolic nodes, then mesocolic nodes then mesenteric nodes along SMA and IMA.
107
