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Q 1-5

Q6-10

Q11-15

Q16-20

Q21. Which of the following is false about the physiology of colon

a) Colectomy increases Na requirement by 80-100 meq/day
b) Short chain fatty acids (SCFA) are produced by bacteria from sugar
c) SCFA have nutrient  value for colonocytes
d) Motility of colon is 8-12 cm/hour
e) Colon absorbs Na and water

Q22) Which is false about hepatic metastasis in colorectal cancers
a) 15-20%  are synchronous with the primary tumor
b) Nodal metastasis is  contraindication for liver resection
c) Lymph nodes at porta  hepatis are contraindication for liver resection
d) Survival is equal whether simultaneous or subsequent resection is done
 

Q23) Which is true? In contrast to ulcerative colitis, Crohn's disease of the colon:

A. Is not associated with increased risk of colon cancer.
B. Seldom presents with daily hematochezia.
C. Has a lower incidence of perianal fistulas.
d Never develops toxic megacolon.


Q24) False regarding Anal sphincter is
       a)Resting pressure is 40mmhg
      b) Squeeze pressure is 50 mmhg
       c) Sympathetic nerves motor to sphincter
       d) External anal sphincter supplied by S2,3,4

25) Which is  false Options to consider when operating for Crohn's disease of the large intestine include:

A. Colectomy and ileorectostomy.
B. Colectomy, closure of the rectal stump, and ileostomy.
C. Colectomy and continent ileostomy (Kock pouch).
D. Proctocolectomy and ileostomy.

Answers
21) d
    In the proximal colon bacteria ferments organic carbohydrates to SCFA acetate, propionate, butyrate. These SCFA augment Na, Cl, water absorbtion and is the fuel for colonocytes
Also they regulate proliferation, differentiation gene expression and immune function in colon.
 

Peristalsis
 

Three types of electrical activity in colonic circular smooth muscle
 

i slow wave- 2-4/min
ii Membranous potential oscillations (MPO) 18/min
iii Action potential superimposed on slow waves and MPO
In humans colonic motor activity varies from quiescence to isolated contractions , bursts of contractions and propagated contractions
The predominant is irregular contractions
Propagated contractions are low (5-40mmhg) and high (75mmhg)
High propagated contractions occur 6 times /day originating in caecum responsible for mass movement occur more while awake and after meals
Schakelford 33

22) b
      25% of the lesions are synchronous, 45% are metachronous
       Before liver resections any primary should  be fully controlled
       although N2 colorectal tumors are met with unfavourable outcome n1 hepatic resections can be done
for other  adverse prognostic factors read maingot 10th edition 1595

23) b

Crohn's disease of the colon is a patchy, segmental, chronic, transmural inflammatory process that penetrates the bowel wall to form fistulas but seldom causes rectal bleeding.

In contrast, ulcerative colitis is a mucosal ulcerating process that extends continuously from the rectum to the more proximal colon and frequently bleeds. Both diseases can develop toxic megacolon, and both predispose the patient to increased risk of malignancy of the large intestine over the long term.

24) b 

Mean resting pressure 40mmhg or 90cm water

 Internal Anal Sphincter contributes 75% of that pressure
Squeeze pressure double of resting pressure. it lasts less than 1 min.

Schakelford 346

25)c
Patients with colonic Crohn's disease who have minimal or mild rectal involvement can be treated by colectomy and ileorectostomy or by colectomy, closure of the rectal stump, and ileostomy. When severe rectal involvement is also present, proctocolectomy with permanent ileostomy is required. The Kock pouch (continent ileostomy) and the ileal pouch;anal canal operation are not performed for Crohn's disease because of the risk of recurrence of Crohn's disease in the ileal pouch in the postoperative period.ose in tropical ones.