6. GI Histology Flashcards Preview

FMS: Pathology > 6. GI Histology > Flashcards

Flashcards in 6. GI Histology Deck (32):
1

1. Correctly identify and describe components of GI tract on histology (objective)

Answer later

2

2. Describe the physiological roles of different parts of the GI tract (objective)

Answer later

3

GI tract common structural features in all regions

1. Mucosa
-Epithelial lining
-Lamina propria (loose connective tissue)
-Muscularis mucosa
2. Submucosa (dense connective tissue)
3. Muscularis Propria
4. Serosa (loose connective tissue)

4

GI Tract Organ List

Esophagus, Stomach, Small Intestine, Large Intestine, Anal Canal

5

Esophagus (Mucosa)

Nonkeratinized stratified squamous epithelium; cardiac glands at lower end

6

Esophagus (Submucosa)

Small esophageal glands (mainly mucous)

7

Esophagus (Muscularis)

Both layers striated muscle in upper region; both layers smooth muscle in lower region; smooth and striated muscle fascicles in middle region

8

Esophagus (Adventitia/Serosa)

Adventitia, except lower end with serosa

9

Stomach (Mucosa)

Surface mucous cells and gastric pits leading to gastric glands with parietal and chief cells (in fundus and body), or to mucous cardiac glands and pyloric glands.

10

Stomach (Submucosa)

No distinguishing features

11

Stomach (Muscularis)

Three indistinct layers of smooth muscle

12

Stomach (Adventitia/Serosa)

Serosa

13

Small Intestine (Mucosa)

Plicae circulares; villi, with enterocytes and goblet cells, and crypts/glands with Paneth cells and stem cells; Peyer patches in ileum

14

Small Intestine (Submucosa)

Duodenal (Brunner) glands (entirely mucous); possible extensions of Peyer patches in ileum

15

Small Intestine (Muscularis)

No distinguishing features

16

Small Intestine (Adventitia/Serosa)

Mainly serosa

17

Large Intestine (Mucosa)

Intestinal glands with goblet cells and absorptive cells

18

Large Intestine (Submucosa)

No distinguishing features

19

Large Intestine (Muscularis)

Outer longitudinal layer separated into three bands, the teniae coli

20

Large Intestine (Adventitia/Serosa)

Mainly serosa, with adventitia at rectum

21

Anal Canal (Mucosa)

Stratified squamous epithelium; longitudinal anal columns

22

Anal Canal (Submucosa)

Venous sinuses

23

Anal Canal (Muscularis)

Inner circular layer thickened as internal sphincter

24

Anal Canal (Adventitia/Serosa)

Adventitia

25

Pancreas

Mixed exocrine and endocrine gland
Produces digestive enzymes and hormones
-Exocrine function: 1.5L of alkaline pancreatic juice per day into the duodenum; proteases, amylase, lipases
-Endocrine function: insulin, glucagon and somatostatin

26

Liver

Main digestive function is bile production
Hepatocytes:Key cells
Functionally diverse: synthesis of plasma proteins, conversion of aa into glucose, produce urea, storage of glucose/vitamin A/iron

27

GI Tract 1/6

Interfaces with outside world to absorb things
-Function: acquire nutrient molecules from food and eliminate indigestible remnants
-Secondary function: maintain barrier between contents of lumen (toxins,bacteria) and rest of body
-Functional tissue is epithelium (varies by location in tract)

28

GI Tract 2/6

Oral cavity, pharynx, esophagus, anal canal: protective mucosa, characterized by abrasion-resistant stratified squamous epithelium

29

GI Tract 3/6

Stomach: secretory mucosa, epithelial glands specialized to secrete acid and digestive enzymes, as well as mucous to protect itself from acid and enzymes

30

GI Tract 4/6

Small intestine: absorptive columnar mucosa interspersed with goblet cells; responsible primarily for absorbing digested nutrients
-Epithelial specializations include folding (plicae and villi) and apical projections (microvilli) to increase surface area for absorption

31

GI Tract 5/6

Large intestine: absorptive/protective mucosa, specializes in water absorption (columnar cells) and mucous secretion (goblet cells)
Especially in large intestine, tight junctions are actually selectively permeable to allow for movement of water and ions

32

GI Tract 6/6

Underlying epithelium: stroma of GI tract includes loose connective tissue (lamina propria), smooth muscle (muscularis mucosa), dense fibroelastic connective tissue (submucosa), more smooth muscle (muscularis externa), and more loose connective tissue (serosa or adventitia)
-Lamina propria+muscularis mucosa: serve as closely related support/localized movement for epithelium and together make up mucosa