Histo Gastro Intestinal Tract

Front 1

Structure of tongue

Back 1

-striated muscle
-fat between bundles
-separated into anterior 2/3 and posterior 1/3 by sulcus terminales

Front 2

3 types of tongue papillae

Back 2

1) filiform
2) fungiform
3) circumvallate

Front 3

Filiform Papillae

Back 3

1) conical, numerous, smallest
2) on dorsal anterior portion
3) extensions of connective tissue w/ keratinized tips
4) no taste buds
5) grip food particles

Front 4

Fungiform Papillae

Back 4

1) taste buds
2) more numerous @ tip
3) dorsal surface
4) mushroom shaped

Front 5

Circumvallate Papillae

Back 5

1) large dome-shaped
2) Von Ebner's glands
3) papillae surrounded by moat-like space lined w/ strat. squamous epith.
4) in mucosa just anterior to sulcus terminales
5) lateral epithelium many taste buds

Front 6

4 layers of alimentary canal

Back 6

1) mucosa
2) submucosa
3) muscularis externa
4) serosa

Front 7

3 categories of MUCOSA

Back 7

1) epithelium
2) lamina propria
3) muscularis mucosa

Front 8

Functions of Epithelium Mucosa

Back 8

1) facilitate passage of bolus
2) semi-permeable layer btwn body and external
3) absorb products of digestion
4) transport to vascular sys.

Front 9

Functions of Lamina Propria

Back 9

1) glands
2) immune system
3) fenestrated vessels
-absorb nutrients
-receive lipids/proteins
4) loose CT
5) absorption occurs small/large intestine

Front 10

Functions of Muscularis Mucosa

Back 10

1) boundary btwn mucosa & submucosa
2) deepest mucosa
3) 2 layers
-outer longitudinal
-inner circular
4) produces movement independent of gut wall

Front 11

Submucosa

Back 11

1) glands in esophagus/ duodenum only
2) lymphatics
3) large blood vessels (supplies other layers)
4) moderately dense irreg. CT
5) nerve plexuses (Meissner's)

Front 12

Muscularis Externa

Back 12

1) 2 concentric thick layers of smooth mm.
2) Myenteric plexus

Front 13

Hirschsprung Disease (congenital mega colon)

Back 13

1) mutations in 1-4 genes
2) arrest of neural cells to 1 portion of distal colon
3) absent enternic NS

Front 14

Serosa vs. Adventitia

Back 14

-serosa: simple squamous epithel. membrane/ most superficial
-adventitia:blends w/ CT of surrounding structures

Front 15

Where is serosa absent?

Back 15

Extraperitoneal organs
i.e. espohagus, duodenum, ascending/descending colon

Front 16

esophagus

Back 16

1) longest, most narrow, most muscular of GIT
2) longitudinal fold mucosa
3) non-keratinized strat. squamous
4) esophageal glands & cardiac glands
5) thick muscularis externa (peristalsis)
6) diffuse lymphatics nodules

Front 17

Does the esophagus have adventitia?

Back 17

Yes, until diaphragm which will have serosa (connects to stomach)

Front 18

2 types of esophageal glands

Back 18

1) proper glands
-submucosa
-mostly in upper half
-acidic & lubricant
2) cardiac glands
-lamina propria
-produces neutral mucosa
-prevents regurgitation
-protects lower 1/2

Front 19

Barret's Esophagus

Back 19

-metaplasia lower 1/2
-caused by acidic damage
-now columnar epithel.
-constant regurgitation

Front 20

What will you see in Barret's Esophagus on a slide?

Back 20

-new columnar epithelium w/ old strat. squamous
-lymphocytes due to chronic infection

Front 21

Stomach

Back 21

-inner longitudinal Rugae
-limited absorption (H2O, NaCl, lipid soluble, OH, some drugs)

Front 22

Stomach epithelium

Back 22

-simple columnar surface mucus
-gastric cells/gastric glands
-PAS stained

Front 23

3 Histological regions of stomach

Back 23

1) Cardia
2) Pylorus
3) Fundus

Front 24

What's another name for Fundic Glands?

Back 24

Gastric Glands

Front 25

What are the length differences btwn gastric glands in Pyloric and Fundis?

Back 25

longer in pyloric, shorter in fundis

Front 26

What are the 5 functional cell types of Fundic Glands?

Back 26

1) mucous neck
2) chief
3) parietal
4) eneteroendocrine
5) undifferentiated

Front 27

Where are the Cardiac glands in the stomach?

Back 27

limited to narrow region near esophagus

Front 28

Cardiac glands

Back 28

-sometimes branched
-tortuous
-tubular
-predominantly mucus secreting (some enteroendocrine)

Front 29

Fundic glands

Back 29

-produce digestive juice
-simple branched tubular

Front 30

Mucous Neck cell

Back 30

-shorter than surface mucus cell
-spherical nucleus
-secretes soluble membrane

Front 31

Parietal

Back 31

-secretes HCl
-"oxyntic"
-beaded appearance
-numerous in upper/ middle
-large, often binucleate
-lots of mitochondria

Front 32

What is significant about the communication system of Parietal cells?

Back 32

-Intracelllular Canalicular System
-communicates w/ lumen of fundic

Front 33

Pernicious Anemia

Back 33

-absence of parietal cells
-inadequate intrinsic factor production
-B12 not absorbed

Front 34

Chief Cells

Back 34

-intensely basophilic
-secretes pepsinogen & weak lipase
-cuboidal (low columnar)
-deepest part of fundic

Front 35

Enteroendocrines

Back 35

-small, hard to identify
-produce gastric cells
-sits on basal lamina

Front 36

Peptic Ulcers

Back 36

-caused by Helicobacterium pylori
-destroys mucus layer
-imbalance btwn damaging factors & protective factors
-unchecked

Front 37

3 main complications of chronic peptic ulcer

Back 37

a) perforation
b) hemorrhage
c) obstruction

Front 38

If you increase pH, what will happen to gastric cells?

Back 38

They will be stimulated

Front 39

Pyloric Glands

Back 39

-branched tubular (coiled)
-empty into deep gastric puts
-neuroendocrine cells interspersed

Front 40

Small Intestine (main pts)

Back 40

-longest
-duodenum, jejenum, ileum
-hormone production
-principal site of digestion/ absorption

Front 41

Small Intestine Lining (Main pts)

Back 41

-Plicae Circularis
-villi
-simple columnar
-Central Lacteal
-Crypts of Lieberkuhn

Front 42

What is Plicae Circularis?

Back 42

-permanent transverse folds that contain core submucosa
-"valves of Kercking"

Front 43

What is central lacteal?

Back 43

-blind ended lymphatic capillary
-in lamina propria

Front 44

Enterocytes

Back 44

-simple columnar
-microvilli @ apex
-secretes glycoalyx

Front 45

Paneth Cell

Back 45

-Found in bases of mucosal glands
-supranuclear golgi
-large apical secretory granules (lysozomes)

Front 46

What do paneth cells probably do?

Back 46

regulate normal bacteria flora in small intestine

Front 47

Enteroendocrines in small intestine function in...

Back 47

secreting hormones that:
-Increase liver / gall bladder activity
-decrease gastric secretion

Front 48

duodenum

Back 48

-plicae circularis
-long prominent villi
-few goblets
-submucosal duodenal glands (of brunner)

Front 49

jejunum

Back 49

-long prominent villi
-more goblet cells
-no submucosal glands

Front 50

ileum

Back 50

-short villi
-goblet cells increase
-Peyer's patches (GALT)
-M cells

Front 51

M cells

Back 51

microfold cells
-overlie peyer's patches
-take up macromolecules from lumen by endocytosis

Front 52

Celiac disease

Back 52

-autoimmune disease
-hypersensitivity to gluten
-weight loss, anemia, steatorrhea
-no villus

Front 53

large intestine

Back 53

-numerous crypts of liberkuhn
-simple columnar epithelium
-absorption of water/electrolytes
-no villi
-more goblet cells

Front 54

Muscularis externa of large intestine

Back 54

no outer longitudinal layer, only inner circular layer

Front 55

appendix

Back 55

thin finger-like extension behind cecum
-complete layer of longitudinal muscle
-large number of lymphatic nodules

Front 56

acute appendicitis

Back 56

-if food is not washed out
-early increase of lymphocytes
-complaints of epigastric pain
-if left untreated, septicemia, shock, death

Front 57

Rectum

Back 57

no tenia
-transverse rectal folds

Front 58

Anal Canal

Back 58

-longitudinal folds "anal columns"
-simple columnar epithelium

Front 59

3 anal canal zones

Back 59

-colorectal zone
-anal transitional zone
-squamous zone