Histology of the GI Tract Flashcards Preview

Gastro > Histology of the GI Tract > Flashcards

Flashcards in Histology of the GI Tract Deck (41):
1

What covers the oral cavity, oropharynx and laryngopharynx

Stratified squamous epithelium

2

What covers the nasal cavity and the nasopharynx

Respiratory epithelium

3

What covers the anterior 2/3rd of the tongue

Stratified squamous epithelium

4

What covers the posterior 1/3rd of the tongue

Smooth stratified squamous epithelium

5

Name the 4 types of papillae on the tongue

Fungiform
Circumvallate
Foliate
Filiform

6

Describe the filiform

They have no taste buds

7

Describe the fungiform

Strawberry pips - lots of taste buds

8

Describe the foliate

Little slits, lined by taste buds- largest surface area due to the presence of slits

9

Describe the circumvallate

Obvious growth structures - serous glands

10

What 4 major layers compose the stereotypical GI tract?

Mucosa
Submucosa
Muscularis Externa
Serosa / Adventitia

11

What are the 3 parts of the mucosa

Epithelium
Lamina propria
Muscularis mucosae

12

What comprises the submucosa

Loose connective tissue

13

What comprises the muscularis externa

Two thick layers of smooth muscle, an inner cicrular layer and an outer longitudinal layer

14

What comprises the serosa or adventitia

Outer layer of connective tissue that either suspends the digestive tract or attaches it to other organs.

15

What is the difference between serosa and adventitia

Serosa - something you can pick up such as the stomach.
The adventitia is something that is more bound down eg the oesophagus

16

Describe the change in cells at the gastro-oesophageal junction

Abrupt transition from stratified squamous epithelium of the oesophagus to the columnar epithelium of the cardia of the stomach

17

What does 1 gastric pit branch into

1-7 gastric glands

18

What are the gastric pits lined by?

Surface mucous cells

19

What are the types of mucosa that can be found in the stomach

Cardia (deep gastric pits that branch into loosely packed tortuous glands)
Body (shallow gastric pits with long straight gastric glands)
Pylorus (deep gastric pits with branched, coiled gastric glands at a higher density than in the cardia

20

Why is the muscularis externa of the stomach unusual?

It contains an additional layer - it is oblique to the usual circular and longitudinal muscle layers and is located internal to the circular layer. This layer aids the churning action of the stomach

21

What is the thickened inner circular layer of smooth muscle?

Pyloric sphincter

22

What are the pits in the small intestine called?

Crypts of Lieberkuhn

23

Describe the length of the duodenum in terms of its different components

Duodenum (25cm)
Jejunum (2m)
Ileum (2.75m)

24

What type of glands can be found in the duodenum

Brunner's glands

25

What is the name of the specialised lymphoid follicles in the ileum

Peyer's patches

26

Where is the plicae circularis found?

Jejunum

27

What is the function of enterocytes

Absorptive cell

28

What is the function of Goblet cells

Produce mucin for protection and lubrication

29

What is the function of paneth cells

Defensive function and a regulating role in bascterial flora

30

What is the function of neuroendocrine cell

Produce hormones

31

What is the function of stem cells

Divide to replenish the epithelium

32

Where are fats deposited

In the lacteal

33

How are Brunner's glands stimulated

With the presence of chyme

34

What do Brunner's glands produce when stimulated

thin, alkaline, mucous to neutralise the chyme

35

What do the colonic glands or the colonic crypts produce

Mucus

36

What are the two principle types of cells in the Large intestine

Absorptive and goblet cells

37

How are the cells in the large intestine arranged

In straight, tubular glands referred to as crypts that extend down the muscularis mucosae

38

Describe the longitudinal smooth muscle in the large intestine

Not continuous
found in 3 muscular strips called teniae coli

39

What is the name of the guts nervous system

Enteric nervous system

40

Where does the ENS receive input from

The autonomic nervous system

41

What else helps to regulate the secretion in the epithelium?

The second netowrk of neurones in the submucosa (submucosal plexus)

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