Anatomycolorectumappendix2 11-3

•

vermiform [ L. vermis, wormlike]

•

blind intestinal diverticlum

•

6 - 10 cm long

•

arises from posteromedial aspect of cecum below ileocecal junction

•

mesoappendix triangular mesentery



retrocecal most common

 pelvic  pre-ileal  sub-cecal  post-ileal

•

Arterial supply - appendicular artery

•

Venous drainage - appendicular vein

•

Lymphatic drainage - ileocolic lymph nodes

•

Nerve supply - superior mesenteric plexus - vagus nerve

Acute Appendicitis Symptoms: right lower quadrant pain McBurney’s point maximal pt of tenderness oblique line from R ASIS to umbilicus distal end of outer third approximates location of appendix approximates placement of incision

Mc Burney’s Point

PHYSICAL FINDINGS: 1. RLQ tenderness = visceral referred pain, T10 s.g. 2. Psoas sign = stretching of psoas by R thigh extension causes pain 3. Obturator sign = stretching of obt. internus by internal rotation causes pain

Cause: ✶ enlarged lymph node ✶ fecalith

Treatment: ✶ Appendectomy

Incision : McBurney’s / Rocky-Davies Locate appendix: trace taenia coli towards posteromedial area of cecum w/c ends as appendix Ligate appendicular a/v = branch of ILEOCOLIC a/v

Complication:

PERFORATION > at midportion [ least blood

supply ] > spreads infection to parietal

peritoneum > greater omentum adheres to

appendix to infection

restrict spread of

•

Consists of: • cecum • ascending colon • transverse colon • descending colon • sigmoid colon

Taenia coli  - 3 thickened band of muscle • Haustra - sacculations between taenia • Appendices - fatty projections of omentum • Internal diameter - larger •

• • •

 • •

comprise longitudinal muscle of LI 3 taenia: 1] omental 2] free 3] mesocolic none in appendix - rectum begins at base of appendix ends at rectosigmoid junction

• • • • •

•

• •

1st part of LI continuous w/ ascending colon about 7.5 cm at right lower quadrant lies in iliac fossa inferior to terminal ileum palpable at abd wall if distended w/ gas or feces enveloped by peritoneum can be lifted freely

• • • •

•

has no mesentery attached to lateral abdominal wall by cecal folds receives the terminal ileum obliquely folds at ileocecal orifice form the ileocecal valve - 2 forms 1. Papillary - common 2. Labial folds meet laterally to form ridges frenulum

CECUM 1. Arterial supply - ileocolic art [ br of SMA] 2. Venous drainage - ileocolic vein 3. Lymphatic drainage - ileocolic lymph nodes Note: same for appendix & cecum 4. Nerve supply - sup. mesenteric plexus - vagus nerve

•

• -



circular muscle poorly developed around orifice not a true sphincter ICV does not control passage of intestinal contents from ileum into the cecum - ICV does not prevent reflux of intestinal contents from cecum back to ileum

4 parts forms an arch 1] Ascending 2] Transverse 3] Descending 4] Sigmoid

- passes superiorly on right side - turns to left below liver as R colic flexure or hepatic flexure -

narrower than cecum

lies retroperitoneally on the R side of posterior abdominal wall -

covered by peritoneum anteriorly and on its sides -

- 45 cm long - largest, most mobile - crosses abdomen from R colic flexure to L colic flexure - L colic flexure [splenic flexure]= more superior, more acute, less mobile compared to R, below spleen - transverse mesocolon [mesentery]= loops down to pelvis - variable in position

- from left colic flexure to

sigmoid - on left side - retroperitoneal - has a short mesentery - has a paracolic gutter on its side

- S shaped loop - 40 cm - connects desc colon and rectum - has long mesentery - thus, has considerable degree of freedom - termination of taenia coli = indicates rectosigmoid jxn - omental appendices = long

- root of sigmoid mesocolon = inverted V shaped attachment - various positions - twisting of root = cause obstruction -Structures near sigmoid > may be injured during surgery on sigmoid > commonly involved by diseases from sigmoid > structures: uterus [female]

1] Ur. Bladder [male] /

1. Arterial supply

Ileocolic art and R colic art [ br of SMA] -

2. Venous drainage

Ileocolic v and R colic v [ trib of SMV] -

3. Lymphatic drainage - Superior mesenteric LN 4. Nerve supply - Superior mesenteric nerve plexus

1. Arterial supply - Middle colic art [ fr SMA] - R and L colic art 2. Venous drainage - SMV 3. Lymphatic drainage - Sup. Mesenteric LN 4. Innervation - Sup mesenteric nerve plexus

1. Arterial supply - Left colic and sigmoid art [ br of IMA] 2. Venous drainage - Left colic and sigmoid vein [ trib of IMV] 3. Lymphatic drainage - Inferior mesenteric LN 4. Nerve supply = a.Sympathetic - Sup.hypogastric pl. b. Parasym = Pelvic splanchnic n.

1. Blood supply and venous drainage: R sided colon, appendix and transverse colon - SMA L sided colon and sigmoid colon - IMA 2. Ileocecal valve permits 2-way passage 3. 3 taenia coli : none in appendix and rectum 4. Lymph nodes grouping follow blood vessels 5. McBurney’s pt is very useful for clinicians

COLON CANCER - may involve any segment Diagnostic tests: 1] Barium enema = xray of colon 2] Colonoscopy = direct visualization 3] CT Scan with Oral and IV contrast

COLON CANCER Symptoms: 1] decreased size of stools 2] constipation 3] blood in stools Treatment: - colon containing the cancerous mass is resected including its arterial and venous drainage - lymph nodes dissected also

Ascending colon cancer = R hemicolectomy - ligate ileocolic, R colic and middle colic vessels Transverse colon cancer = Transverse colectomy - ligate middle colic, R and L colic vessels Descending colon cancer = L hemicolectomy - ligate left colic vessels Sigmoid colon cancer = Sigmoidectomy

- long mesentery - very mobile - can be visualized w/ sigmoidoscope - 25 cm from anus - common site of large intestinal obstruction as: 1] Volvulus twisting of mesosigmoid 2] Cancer - most common site 3] Diverticulitis- connects to UB form fistula

Familial Adenomatous Polyposis Coli

Familial Adenomatous Polyposis Coli

Carcinoma of the Colon (annular type)

Crohn’s Colitis

Perforated Diverticle

Tuberculosis

Pseudomembranous Colitis