S3) Anatomy of the Abdomen Flashcards Preview

Y2 SEM 3: Gastro-intestinal System > S3) Anatomy of the Abdomen > Flashcards

Flashcards in S3) Anatomy of the Abdomen Deck (50)
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1

State the structure and functions of the mucosal epithelial layer

Structure: selectively permeable barrier

- Function: promote absorption, produce hormones and mucus, facilitate transport and digestion of food

2

State the structure and function of the mucosal lamina propria

- Structure: lots of lymphoid nodules and macrophages

- Function: produce antibodies (mainly IgA)

3

State the structure and functions of the muscularis mucosae

Structure: layers of smooth muscle orientated in different directions

- Function:

I. Keeps epithelium in contact with gut contents

II. Keeps crypt contents dynamic 

4

Describe the structure of the submucosa of the gut

- Contains dense connective tissue, blood vessels, glands, lymphoid tissue

- Contains submucosal plexus (Meissner’s) 

5

Describe the contents of the inner circular muscle layer

Contains myenteric (Auerbach’s) plexus 

6

Describe the structure of the serosa in the gut

- Continuous with mesenteries 

- Contains blood and lymph vessels and adipose tissue

7

What kind of epithelia is found in the gut?

- Stratified squamous (oesophagus and distal anus)

- Simple columnar (everything else)

8

What is an enterocyte?

An enterocyte is a simple columnar epithelial cell that absorbs nutrients

9

The enterocyte is the most predominant cell in the small intestine and lumen.

Describe it structure

- Consists of apical and basolateral membranes

- Blood vessels/lymphatics lie immediately below cell

 

10

How are enterocytes adapted for their absorbative function?

Microvilli (collectively termed brush border

11

Where are goblet cells found?

- Scattered in between enterocytes

- Increase in number from duodenum to colon

12

Describe the structure of the goblet cell

- Narrow base (mucus compresses nucleus to its base)

- Larger apical size

13

Goblet cells secrete mucus.

What are the three main functions of mucus?

Protects epithelia from:

- Friction (acts as lubricant)

- Chemical damage (acidic environment)

- Bacterial inflammation (forms physical barrier) 

14

Where are gastric surface mucous cells found?

Gastric surface mucous cells line gastric mucosa/gastric pits

15

What do gastric surface mucous cells do?

Secrete mucus/HCO3 that forms barrier to stomach acid 

16

How is the gut tube adapted for the increased surface area required for absorption?

- Permanent folds

- Villi

- Microvilli 

17

Why does the stomach form temporary folds?

- The stomach needs to be easily expandable

- Temporary folds form called rugae 

18

Crypts are found in the small intestine and colon.

What type of cells do they contain?

Contain specialised cells:

- Stem cells

- Paneth cells

- Enteroendocrine cells 

19

What are stem cells?

Stem cells are cells that reside in crypts that constantly divide to replace epithelia 

20

Where are paneth cells found and what do they do?

- Location: base of crypts

- Function: secrete antibacterial proteins to protect stem cells

21

How can paneth cells be identified?

Paneth cells contain vesicles which stain red

22

Where are enteroendocrine cells found and what do they do?

- Location: deeper in crypts and gastric glands

- Function: secrete hormones that control the function of the gut e.g gastrin, CCK, secretin

23

Briefly, identify states where crypts are affected by inflammatory bowel disease

Crypt alteration

- Cryptitis – inflammation of wall

- Crypt abscess – neutrophils in lumen 

24

Describe the organisation of glandular tissue in the gut

- Organised secretory cells – acini and tubules

- Connected to a duct 

25

Provide 3 examples of exocrine glands in the gut

- Salivary glands

- Pancreas

- Brunners glands 

26

Differentiate between the secretions of acini and tubules

- Acini secrete serous secretions (+ enzymes)

- Tubules secrete mucous e.g. Brunner’s glands

27

What type of secretions do salivary glands produce?

- Serous secretions 

- Mucous secretions

28

Describe the pathophysiology of ulceration of the gut

- Erosion through muscularis mucosae

- Failure of protective mechanisms e.g. mucus production 

29

Describe the pathophysiology of Coeliac's disease

- Inability to tolerate gliadin

- Damages mucosa

- Results in poor digestion and malabsorption 

30

Identify the 5 layers composing the abdominal wall

- Skin

- Fascia/fat: superficial and deep

- Anterolateral muscles

- Transversalis fascia

- Peritoneum