GASTROINTESTINAL SYSTEM BLOCK PROBLEM 5

ALMIRA NABILA VALMAI405130193

LO

1. Anatomi dan histologi saluran pencernaan bawah

2. Fisiologi dan biokimia proses defekasi

3. Kelainan saluran pencernaan bawah

ANATOMI DAN HISTOLOGI SALURAN PENCERNAAN BAWAH

LO 1

Small Intestine

• 90% of absorption occurs in the small intestine

Large Intestine

Colon panoramic view, transverse section

Colon transverse section

Appendix panoramic view, transverse section

Rectum panoramic view, transverse section

FISIOLOGI DAN BIOKIMIA PROSES DEFEKASILO 2

Faeces in colon

Rectum stretches

stretch receptor stimulation

Reflex defecation

Relax sfingter ani interna

Rectum, colon sigmoid contraction more harder

defecation Sfingter ani externa

relaxco

ntra

ction

delayed defecation

rectal wall that stretched to relax

defecation desire abate

feces are pushed more into the rectum

defecation

Mecanism of Defecation

1. Haustra contraction.

– Initiated by autonomous rhythmicity of colonic smooth muscle.

– These contraction throw the large intestine into haustra, are similiar to small intestine segmentation but occur much less frequently.

– These movements are nonpropolsive; they slowly shuffle the contents in a back-forth mixing movement that exposes the colonic content to the absorbtive mucosa.

2. Mass movements• It is massive contraction that drive the colonic content into

the distal part of the large intestine, where material stored until defecation.

3. Gastrocolic reflex– Causes of mass movements are triggered in the colon

primarily.– Mediated from the stomach to the colon by gastrin and by

extrinsic autonomic nervous.– This reflex is most evident after the first meals of the day

and is often followed by the urge to defecate.

Reflexes in Colon and Rectum:

KELAINAN SALURAN PENCERNAAN BAWAHLO 3

Inflammatory Bowel Disease

Hirschprung

Anal disorders

Irritable Bowel Syndrome

Diverticulosis

Dysentery (Entamoeba histolytica)

Dysentery (Shigella)

Food intolerance

Colon carcinoma