Histology of the GI tract

Question 1

What is the hierarchical organisation?

Answer 1

Cells (ultrastructural level)

Tissues (molecular level)

Organ

Organ system

Organism

Question 2

What is the first question you should ask yourself when looking at a histological image?

Answer 2

How magnified the image is

Question 3

What are the 4 basic types of tissues?

Answer 3

Epithelial

Connective tissue

Muscle tissue

Nervous tissue

Question 4

What are different classifications of epithelial tissue?

Answer 4

Columnar

Cuboidal

Squamous

Question 5

What is epithelial tissue?

Answer 5

Tissue on the surface

Question 6

What is connective tissue?

Answer 6

Space filling tissue

Question 7

What are the functions of muscle tissue?

Answer 7

Contractions, movement

Question 8

What are the functions of nervous tissue?

Answer 8

Integrates and coordinates

Question 9

What is a tissue?

Answer 9

Group of cells that work together and perform the same function

Question 10

What is a tissue formed from?

Answer 10

Cells and extracellular substance

Question 11

What is an organ formed from?

Answer 11

Two or more types of tissues

Question 12

What are the layers of the muscularis externa?

Answer 12

Inner circular muscle

Outer longitudinal muscle

Question 13

What is the classification of the epithelium in th eoesophagus?

Answer 13

Stratified squamous non-keritinised epithelium

Question 14

What kind of muscle is the upper 1/3 of the muscular layer of the oesophagus?

Answer 14

Skeletal muscle

Question 15

What kinds of muscle is the middle 1/3 of the muscular layer of the oesophagus?

Answer 15

Smooth muscle and skeletal muscle

Question 16

What kind of muscle of the lower 1/3 of the muscular layer of the oesophagus?

Answer 16

smooth muscle

Question 17

What do parietal cells secrete?

Answer 17

(stain pink) – secrete HCl

Question 18

What do chief cells secrete?

Answer 18

at base of the gland – secrete pepsinogen

Question 19

What is the classification of the epithelium in the stomach?

Answer 19

Simple columnar epithelium

Question 20

In what layer are the gastric glands in the stomach found?

Answer 20

Gastric glands in mucosa (above muscularis mucosae)

Question 21

What is unique about the muscularis externa of the stomach?

Answer 21

3 layers of muscles in m.externa (if you can see this layer in the micrograph)

Question 22

What is found in the mucosa of the small intestine?

Answer 22

Lymphoid aggregations in mucosa - Peyer’s patches

Question 23

What are crypts of Leiberkuhn?

Answer 23

The crypts of Lieberkuhn (often referred to simply as crypts) are similar to the gastric pits in the stomach. The crypts contain stem cells that can differentiate to produce a number of different cell types, including enterocytes

Question 24

Where are Brunner’s glands found?

Answer 24

duodenum in submucosa

Question 25

In what part of the GI tract are peyer’s patches found?

Answer 25

ileum

Question 26

Where in the GI tract do villi first appear?

Answer 26

They are most prevalent at the beginning of the small intestine and diminish in number toward the end of the tract.

Question 27

What are Paneth cells?

Answer 27

Paneth cells are secretory cells located in the crypts of Lieberkühn, adjacent to the intestinal stem cells. They produce antimicrobial peptides and proteins and other components that are important in host defense and immunity.

Question 28

What does the large intestine contain histologically?

Answer 28

Thick mucosa, crypts, mucous secreting cells. No villi.

Question 29

What are some glands of the GI tract?

Answer 29

Salivary glands (in head/neck block) Pancreas Liver (very elaborate gland!)

Question 30

What is the secretory component of exocrine glands?

Answer 30

Secretory (acinar component) – roundish structure with columnar cells and nuclei at the base

Question 31

What are the 3 major pairs of salivary glands?

Answer 31

Salivary glands (in head/neck block) Pancreas Liver (very elaborate gland!)

Question 32

what are the histological parts of the pancreas?

Answer 32

1 – Islet of Langerhans – endocrine part – no acini 2 – exocrine part – pancreatic acini 3 – pancreatic duct ( for exocrine part)