2. • Small intestine measurements taken at
autopsy ( cadaver examination ), because of
endoscope and coloscope cant reach small
intestine (iluem) so its suggests that adult
lengths of small intestine between 3 & 9
meters.
3. Histology of small intestine
• Once we have a duodenal biopsy we have to count
lymphocyte, if they are more than 20 mean
inflammation
4.
5. Why ?because the presence of goblet cells ( which secretes
mucus along the whole intestines ) is not sufficient to protect
the duodenum from the gastric acids .
6. Brunner’s glands
• tuboalveolar( or tubule-acinar ) glands .
• have ducts that open directly into the crypts
of lieberkuhn .
• Has Urogastrone : an enzyme that is secreted
to the blood ,it goes to the parietal cells and
inhibits their acid secretion .
7. folding of lamina propria and epithelium
Goblet cells : (uni-cellular ) that
secrete mucinogen (
mucus precursor ) to lubricate
the small intestine
I , S cells
Paneth cells (defense
cell) :Apical eosinophilic
granules: secrete
lysozymes
enterocyte
Intestinal gland
12. • As we going from duodenum to ileum number
of lymphocytes are increased
• why ?
• Coz the food will converted to fecal material
>> that’s increase number of bacteria>> and
should be balance between bacteria and
inflammatory cells .
13. • Atresia : absence of canalization where as
stenosis is narrowing of lumen >
• Duodenal Atresia is associated with Down syndrome
failure to recanalize
(trisomy 21).
14. there is a reminant of the yolk sac
“persistence”
15.
16. • Located in distal ileum usually within (2 feet )
• the blend segment or pouch is about (2inch)
long.
• most common malformation of GIT (2% of
population ).
• true diverticulum its mean that bulging part
have 3 layers not 2(false)” more common”.
The complication of this disease are pain and bleeding which may mimic
appendicitis therefor , during appendectomy , ileum should be checked for
presence of meckel's diverticulum , if it is found to be present it
should be removed with appendix
its role of 2
17. • Heterotopic rests of gastric mucosa and
pancreatic tissue (rare ) .
• heterotopic means displacement of an organ
from its normal location
infracolic compartment.
supracolic compartment.
18. Meckel diverticula may contain ectopic gastric mucosa (which can
ulcerate surrounding mucosa with pain and bleeding) or ectopic
pancreas (which is of no consequence unless it forms a mass large
enough to predispose to intussusception).
20. Volvulus
• Mostly in small intestine; large intestine
especially sigmoid and cecum.
• Rare.but
Most common
In adults.
21. The nervous system in GI has 2 networks
(plexuses) of nerves :(Enteric Nervous System):
• 1.Meissener’s submucosal plexus:-
- related to the secretory function.
- it Stimulates the contraction of muscularis
mucosa and the contraction of the endothelial
and other cells in ( glands and blood vessels )
- Neurotransmitter Vasoactive Intestinal
Peptides (VIP) and Nitric Oxide (NO) cause the
smooth muscle contraction and thus increase
blood flow to intestinal epithelium.
22. • 2. Auerbach’s myenteric plexus أورباخ=قوي
-within the muscularis externa > (between the
inner circular and the outer longitudinal
>movement.
-They are excitatory , but some are inhibitatory
(They secrete (VIP) which inhibit intestinal
sphinctre muscles like: pyloric sphinctre &
ileocecal valve .
32. • Classification of diarrheal disorders :-
• 1- Secretory diarrhea :-
-Secretory diarrhea means that there is an increase in the
active secretion, or there is an inhibition of absorption.
-There is little to no structural damage
-The most common cause of this type of diarrhea is a
cholera toxin that stimulates the secretion of anions,
especially chloride ions. Therefore, to maintain a charge
balance in the lumen, sodium is
carried with it, along with water
33. • 2- Osmotic diarrhea
• occurs when too much water is drawn into the
bowels. If a person drinks solutions with
excessive sugar or excessive salt, these can
draw water from the body into the bowel and
cause osmotic diarrhea.
• Osmotic diarrhea can also be the result of
maldigestion :(e.g., pancreatic disease or
Coeliac disease), in which the nutrients are
left in the lumen to pull in water.
• Or it can be caused by osmotic laxatives
(which work to alleviate constipation by
drawing water into the bowels)
34. • 3- Exudative diarrhea:-
• Exudative diarrhea occurs with the presence
of blood and pus in the stool. This occurs with
inflammatory bowel diseases,( bacterial).
• 4- Malabsorption diarrhea :-
• unabsorbed nutrients & fat.
• 5- Deranged motility diarrhea :-
• decreased intestinal retention time; decreased
motility. WHY??
• Because it leads to bacterial overgrowth
infection diarrhea
