Morphology and histology - PowerPoint Presentation

Slide1

Morphology and histology of small intestine and pancreas

Dr. Ágota Ádám

Duodenum

and

pancreas

(drawing!)

jejunum

ileum

thicker

wall

wider

mesentery 2 arteries enter the bowel wall

Capsule

endoscopy

Specimens of the jejunum (

A)

and

ileum

(

B)

from a cadaver where the

superior

mesenteric artery was injected with red-coloured gelatin before fixation. The largest vessels present are the jejunal and ileal branches

of the superior mesenteric artery and these are succeeded by

anastomotic

arterial arcades,

which

are relatively few in number (1–3) in the jejunum, becoming more numerous (2–6) in the ileum. From the arcades, straight arteries (arteriae recta) pass towards the gut wall; frequently, successive straight arteries are distributed to opposite sides of the gut. Note the denser vascularity of the jejunal wall.

A

B

Meckel’s

diverticulum

–

remnant

of

the

vitteline

duct (2-3% of the individuals)

Rectus hüvely/M. rectus abdominis

Costa

Lobus sin. hepatis, segmentum med. IV.

Lobus sin. hepatis, segmenta latt. II-III.

Duodenum

Gaster (antrum)

Colon

Art. hepatica

V. portae

Pancreas (collum)

Jejunum

V. lienalis

Cauda pancreatis

Gl. suprarenalis sin.

V. cava inf.Crus diaphragmatis

A. mesenterica sup.

Aorta

Vertebra thorac. XII.

M. erector spinae

Ren sinister

Lien

Abdomen

,

axialis

CT

Histology of the small intestine

–

basic

features

Submucosa

Tunica

muscularis

Tunica

s

erosa

(

adventitia

)

Tunica mucosa (

epitelium

+

propria

+

lamina

muscularis mucosae)INTESTINAL VILLI

– with culticle

Simple columnar

epithelium

+

g

oblet

cells

Lacteal

(

lymph

vessel

)

CRYPTS of LIEBERKÜHN

Cuticule

(

brush

border

)

Goblet

cells

Intestinal

villus

Crypt

of

LieberkühnLamina muscularis

mucosae

propria

Epithelial

cell

types

in

the

small intestineEnterocytes (simple columnar, with

cuticule)Goblet

cells

Enteroendocrine

cells (→ bioactive peptides: gastrointestinal hormones, eg: cholecystokinin, secretin, gastric inhibitory polipeptide, motilin, etc.)Paneth cells

– at the bottom

of

the

crypts

;

large

eosinophilic granules with anti-microbial agents (lysozyme) – Protection

and regulation of the normal

bacterial flora

5.

Stem

cells

(

multipotent

–

they

can

create

all

cell

types

in

the

intestinal

epithelium

)

DuodenumJejunum

Ileum

Brunner’s

glands

in

the

submucosa ! –

mucus-rich

alkaline

secretion to protect the duodenal mucosa (neutralizing the stomach acid)Brunner’s glandsWhich part of the

small intestine? - Check

the

subucosa

!

‘

nothing special

’

Peyer’s patches in the submucosa! - aggregated lyphoid

nodules

;

members

of MALT;

B-dependent

zone

Only

in

the

anti-mesenterial

side!

Peyer’s

patch

Kerckring

valves

(

folds

)

Histology of the pancreas

Exocrine

component

Endocrine

component

Serous

gland

–

pancreatic

acini

(basophilic cytoplasm & zymogen granules – contain digestive enzymes )Centroacinar

cells= intercalated duct

cells

located

in

the acinusIslets of Langerhans

Hormone secretion, regulates

blood sugar level (glucagon: ⇑ ; insulin:

⇓ )

PP

:

self-regulate

pancreatic

secretion

activities

Secretion

⇓

Histology

of

the

pancreas

Paccinian

corpuscles

Islet

of

Langerhans

Serous

acini

Islet

of

Langerhans

Why

am I

studying

this…? I will

be a

dentist

!

There

are several diseases of the GI system that couse signs and symptoms

in the oral cavity

.

Here

are

a few examples: Gastric reflux – chronic reflux couses characteristic enamel erosion Gardner syndrome (genetic disease characterized by intestinal polyposis with a very high risk of malignant transformation into adenocarcinoma):

Enamel

erosion

in

a

bulimic

patientOral

lesion

in ulcerative colitis

-

multiple

enostoses

of the

jaws

-

supernumary

and/or

unerupted

teeth

-

increased

risk of odontomas

Thank

you

for your

attention

!