Histology Of SI And LI

Question 1

Transverse folds of the SI

Answer 1

PLICAE CIRCULARES
within the submucosa
Not that visible in Ileum, very visible in Jejunum

Increase SA (and even more with the villi) and dilation

Question 2

Intestinal Villi

Answer 2

On the plicae circulares
Project into lumen of SI
Simple columnar + goblet cells + enterocytes

Vascularized and CT and LACTEAL inside the villi

Question 3

Lacteals

Answer 3

Inside the SI villi and absorb lipids from the lymph vessels that go through it and carry lipids from lumen

Question 4

Microvilli

Answer 4

Every cell on the villi, except Goblet cells, have microvilli
EVEN MORE INCREASED SA

Question 5

Enterocytes

Answer 5

Decrease enzymes for digestion and absorption

Question 6

Goblet cells

Answer 6

Make mucus coating for protection from abrasion or bacteria

Question 7

Mucosa Layer of SI

Answer 7

Simple columnar (tubular SI glands)
Lamina Propria + Muscularis mucosae

Question 8

Submucosa Layer of the SI

Answer 8

Dense irr CT

Nerves, Vascularized, L, Glands (in some parts)

Question 9

Muscularis Externa of SI

Answer 9

Inner + outer layer

Question 10

Serosa Layer of SI

Answer 10

loose CT covered by visceral peritoneaum (mesothelium)

Question 11

Innervation to SI and LI

Answer 11

ENS from the Gangionic cells
in connection with the ANS
1. Meissenteric plexus = move plicae circulares and mucosa
2. Myenteric plexus = peristalsis and mixing
(Para: vagus and pelvic N,,,, Sympa: postganglionic)

Question 12

SI glands are called

Answer 12

Crypts of Lieberkuhn’s

Question 13

Intestinal Glands 4 types

Answer 13

CRYPRS, Lined by simple columnar

1. Paneth cells
2. M (Microfold) cells
3. Intestinal Stem cells
4. ENTEROENDOCRINE cells

Opens to lumen at the base of the villi

Question 14

Paneth Cells

Answer 14

Pyramidal, at the base of the glands BIG EOSINOPHILIC (Dr. andersons favorite)
= innate immunity - secrete anti microbial substances (Lysosome, a-Defensins)
= Regulate normal bacteria flora by antibacterial and phagocytic activity

Question 15

Intestinal Stem Cells

Answer 15

At the base of the crypt near paneth cells
Regenerate the epithelium
ISC—-> Goblet cell + Enterocytes + ENTEROENDOCRINE cells

Question 16

M (Microfold) Cells

Answer 16

epithelial cells
= transepithelial transport of particles and microorganisms
In ILEUM mucosa, over Peter Pateches
= invaginate membrane and hold macrophages and lymphocytes there
= APICAL: receptors bind to gram - (E-coli), internalize it and transfer to the immune cells
*highly specialized Ag- transporting cells

Question 17

Which part of the SI has submucosal glands

Answer 17

Duodenum

Acinar mucous glands = alkaline for neutralization

Question 18

Which parts of the SI has villi with a lacteal

Answer 18

Jejunum

Question 19

Which part of the SI has intestinal glands (crypts)

Answer 19

in mucosal layer
Jejunum distinct
Only also Ileum and Duodenum

Question 20

Which part of the SI has lymph in lamina Propria

Answer 20

Jejunum

Question 21

Which part of the SI has villi with no lacteal

Answer 21

Ileum, Duodenum ?

Question 22

Which part of the SI has Peyer’s patches and what are they

Answer 22

Lymphoid nodules (MALT) 
Ileum

Question 23

Which part of the SI has Panath Cells

Answer 23

At the base of Crypts

Ileum

Question 24

Gastroduodenal Junction is by Pyloris and Duodenum

Answer 24

Pyloris - thick wall with sphincter
- gastric pits with pyloric glands

Duodenum - Many duodenal glands in submucosa
-ecreatory mucosa with villi

Question 25

Function of the LI

Answer 25

Absorb H2O, NA, VIT, Minerals, anesthesia, steroids, sedatives
NO VILLI
GOBLET CELLS
Tubular intestinal crypts (glands)

Question 26

Mucosa Layer of the LI

Answer 26

Glands, Simple columnar
COLONOCYTES
GC
SC
enteroendocrine cells 
GALT

Question 27

Submucosa Layer of the LI

Answer 27

Dense irr CT VASCULARIZED

Question 28

Muscularis Externa Layer of the LI

Answer 28

Outer layer has TAENIAE COLI that for HAUSTRA *most prominent on transverse colon
Inner layer is normal SM

Question 29

Hirschprung’s Disease

Reason

Answer 29

Aganglionosis in the distal colon 
Mutations of the RET gene : X migration and differentiation of NCC 
= no NCC in plexuses and Bowel
Rectosigmoid (85%)
Rectosigmoid—> Splenic flexure (10%)

Question 30

Hirschprung’s Disease
Sx:
Dx:
Tx:

Answer 30

Constipation, poor feeding, ABD dissension progressive

Delayed Bowel Movement (48hr after birth), Rectal biopsy, Barium Enema

Surgical removal, and pull through ganglionic colon segment and reattaching

Question 31

Rectum Proper

Answer 31

Upper Part of Rectum

Transverse rectal folds, glands, mucosa

Question 32

Anal Canal

Answer 32

Lower Part of Rectum

1. Anal Columns: mucosal folds
2. Anal sinus : Depression between columns
3. Anal Gland : in submucosa and Muscularis Externa

Question 33

Which glands surround the anal Orifice

Answer 33

Circumanal Glands, Large Apical Glands

Question 34

Anal Canal 3 sections

Answer 34

PECTINATE LINE
COLORECTAL ZONE 1/3
-simple columnar epithelium
ANAL TRANSITION ZONE ATZ 1/3
-simple columnar +non-kerit. stratified squamous of perineal skin
SQUAMOUS ZONE 1/3
-stratified squamous continuous with perineal skin (upper is non-ker. And then becomes Ker. By skin

Question 35

What makes the inner Anal Sphincter

Answer 35

The inner layer of Muscularis Externa

Question 36

Bruners Glands are

Answer 36

Submucosal glands