GI

Question 1

Why do stem cells stain darker?

Answer 1

Bigger and more active nuclei

Question 2

Describe the muscle of the oesophagus

Answer 2

Top 1/3 is voluntary muscle in fascicles
Middle 1/3 is mixed
Distal 1/3 is involuntary smooth muscle

Question 3

Where are mucous glands found?

Answer 3

Submucosa= submucosal glands

Lamina propria= superficial glands

Question 4

List the cells found in the lamina propria

Answer 4

Fibroblasts, lymphocytes, plasma cells, macrophages, eosinophils, mast cells

Question 5

What is found in the sub mucosa?

Answer 5

Blood vessels, lymph vessels, nerves

Question 6

What is the mucosa?

Answer 6

Epithelium + lamina propria+ muscularis mucosa

Question 7

What is Barrett’s oesophagus?

Answer 7

Epithelial metaplasia of the oesophagus
Injury to the mucosa from GORD leads to a change from non keratinised strat squamous epithelia to glandular simple columnar

Question 8

What is Barrett’s oesophagus?

Answer 8

Epithelial metaplasia of the oesophagus
Injury to the mucosa from GORD leads to a change from non keratinised strat squamous epithelia to glandular simple columnar

Question 9

What are the 4 areas of the stomach called?

Answer 9

Cardia, fundus, body and pylorus

Question 10

What cell types are found in stomach glands?

Answer 10

Epithelial cells, parietal cells (HCl and intrinsic factor)
chief cells (pepsinogen and gastric lipase)
enteroendocrine cell

Question 11

How do you identify parietal cells and chief cells?

Answer 11

Parietal- lumpy, paler cells

Chief- look columnar like epithelium but dark with granules

Question 12

How do you identify parietal cells and chief cells?

Answer 12

Parietal- lumpy, paler cells

Chief- look columnar like epithelium but dark

Question 13

What factors can lead to ulcer formation?

Answer 13

Increased acidity
decreased mucous
diet
decreased prostglandins (due to NSAIDs?)

Question 14

What factors can lead to ulcer formation?

Answer 14

Increased acidity
decreased mucous
diet
decreased prostaglandins (due to NSAIDs?)

Question 15

Describe the villi of the small intestine

Answer 15

Duodenum- leaf like villi
Jejunum- fine tall villi
Ileum- finger like villi

Question 16

What are the 3 features of the small intestine to increase absorption

Answer 16

Villil microvilli, circular folds (plicae circulares)

Question 17

What are the intestinal crypts also called?

Answer 17

Crypts of Lieberkuhn

Question 18

Function of paneth cells?

Answer 18

Contain antimicrobial granules (of defensins) and contribute to host-defence and the maintenance of the GI barrier. Found at base of crypts. Stain darkly eosinophilic

Question 19

Name the cells of the epithelium of the small intestine

Answer 19

Goblet cells, enterocytes, enteroendocrine cells and paneth cells.

Question 20

What is a Peyer’s patch?

Answer 20

Aggregation of lymphoid tissue, found in ileum and appendix (nodules of lymphoid follicles)
Lymphoid aggregates and the darker stained B cell aggregates

Question 21

How does the pyloric region of the stomach differ from the fundic region of the stomach?

Answer 21

Fundus- long narrow glands
Pylorus- deeper pits, shorter more branched glands, fewer parietal cells, mainly mucous secreting cells
G cells (gastrin) and serotonin and somatostatin secreting cells

Question 22

What are G-cells? + function

Answer 22

G-cells are enteroendocrine cells of the pyloric region of the stomach
Gastrin secreting cells

Question 23

What are Brunner’s glands?

Answer 23

Submucosal glands of the proximal duodenum, secrete alkaline mucus to counteract acidity of chyme and lubricate walls

Question 24

What is a Peyer’s patch?

Answer 24

Aggregation of lymphoid tissue, found in ileum and appendix

Lymphoid aggregates and the darker stained B cell aggregates

Question 25

How does the pyloric region of the stomach differ from the fundic region of the stomach?

Answer 25

Fundus- long narrow glands | Pylorus- deeper pits, shorter more branched glands, fewer parietal cells

Question 26

What are G-cells? + function

Answer 26

G-cells are enteroendocrine cells of the pyloric region of the stomach Gastrin secreting cells

Question 27

Difference between colon and rectum?

Answer 27

Rectum's crypts are much longer and are almost entirely formed of goblet cells

Question 28

Why is less mucus produced in the colon?

Answer 28

Less acid so less damage, don't need mucus protection | Function of colon is mainly water absorption

Question 29

Difference between Crohn's and ulcerative colitis ulcers?

Answer 29

Croh's- transmural | UC- only mucosal

Question 30

What is the appendix?

Answer 30

Blind ended diverticulum extending from caecum

Question 31

Difference between colon and rectum?

Answer 31

Rectum's crypts are much longer and are almost entirely formed of goblet cells

Question 32

What do myoepithelial cells do in glands?

Answer 32

Surround the gland and squeeze it to aid in secretion

Question 33

Why are liver lobules split into zones?

Answer 33

Based on distance from portal triad | Zone 3 is furthest from blood supply and closest to central vein so more susceptible to hypoxia

Question 34

What salivary gland is both mucous and serous secreting?

Answer 34

Submandibular

Question 35

What are the main functions of zone 1 hepatocytes?

Answer 35

Gluconeogenesis, B-oxidation of fatty acids, bile acid secretion

Question 36

What is the space surrounding the sinusoids of the liver called? What does it contain?

Answer 36

Space of Disse, contains collagen, fibrin and stellate cells

Question 37

Why are liver lobules split into zones?

Answer 37

Based on distance from portal triad | Zone 3 is furthest from blood supply and closest to central vein so more susceptible to hypoxia

Question 38

How do you identify the endocrine parts of the pancreas?

Answer 38

Islet of langerhans stain more paley

Question 39

What are the main functions of zone 1 hepatocytes?

Answer 39

Gluconeogenesis, B-oxidation of fatty acids, bile acid secretion

Question 40

Where in the liver does paracetamol injury and alcohol induced fibrosis occur?

Answer 40

Zone 3

Question 41

What is the function of most of the pancreas?

Answer 41

Exocrine secretions of digestive proenzymes- pancreatic lipase, DNase, trypsinogen, elastase etc

Question 42

How do you identify the endocrine parts of the pancreas?

Answer 42

Islet of langerhans stain more paley

Question 43

What are trefoil factors?

Answer 43

Proteins that aid barrier repair and would healing

Question 44

What cells are found above peyer's patches?

Answer 44

M-cells (microfold cells) | Transport proteins, viruses and bacteria from gut lumen to antigen presenting cells in basal layer

Question 45

Name the 2 lines that reflect a change in the epithelium in the rectum and anal canal

Answer 45

Dentate/pectinate line and Hilton's white line

Question 46

Function of anal sinuses

Answer 46

Secrete mucus, found just above anal valves

Question 47

What is the dentate line also called? What does it signify?

Answer 47

Pectinate line Divides the upper two thirds and lower third of the anal canal. Developmentally, this line represents the hindgut-proctodeum junction (non kerat->kerat st sq epithelium)

Question 48

What is Hilton's white line?

Answer 48

Hilton's white line is slightly below the pectinate line, a landmark for the intermuscular border between internal and external anal sphincter muscles.

Question 49

What is the innervation of each anal sphincter?

Answer 49

``` Internal= pelvic splanchnic nerves (S4) symp+parasym External= S4 + pudendal nerve ```

Question 50

Describe the parts of the GI tract with 'abnormal' muscularis externa

Answer 50

``` Oesophagus= longitudinal only Stomach= inner oblique->circular->outerlongitudinal ```

Question 51

Describe the parts of the GI tract with 'abnormal' muscularis externa

Answer 51

``` Oesophagus= longitudinal only Stomach= inner oblique->circular->outerlongitudinal ```

Question 52

What can enteroendocrine cells produce? Where are they secreted?

Answer 52

Glucagon, somatostatin, serotonin, substance P, histamine, gastrin, CCK, GIP, VIP, neurotensin, secretin Secreted into lamina propria

Question 53

What do chief cells produce?

Answer 53

Pepsinogen, renin and gastric lipase

Question 54

Name the 2 lines that reflect a change in the epithelium in the rectum and anal canal

Answer 54

Dentate/pectinate line and Hilton's white line

Question 55

What do chief cells produce?

Answer 55

Pepsinogen, renin and gastric lipase

Question 56

How do you tell if glands are mucous or serous secreting?

Answer 56

Mucous is lightly stained, serous is darkly stained

Question 57

What 4 vessels are you looking for in a liver slide?

Answer 57

Hepatic portal vein, bile duct and hepatic artery = triad | Central vein

Question 58

Cell type of gall bladder wall?

Answer 58

Simple columnar with abundant microvilli

Question 59

Cell type of gall bladder wall?

Answer 59

Simple columnar with abundant microvilli

Question 60

Risk factors for gall stones?

Answer 60

Fat, fair, forty, fertile, female

Question 61

What stains basophilic in pancreatic exocrine cells?

Answer 61

The zymogen granules near the nucleus

Question 62

What is the function of exocrine pancreatic secretions?

Answer 62

Enzyme rich alkaline fluid to digest proteins, carbs, lipids and nucleic acids

Question 63

How can gallstones cause pancreatitis?

Answer 63

Bile duct goes through pancreas and pancreatic duct and bile duct meet, could obstruct both with gall stones

Question 64

Whats the most common cause of pancreatitis?

Answer 64

Excessive alcohol consumption

Question 65

What do the endocrine cells of the pancreas produce?

Answer 65

``` ß cells- insulin α cells- glucagon ∂ cells- somatostatin G cells- gastrin PP cells- pancreatic polypeptide ```

Question 66

How are the hepatocytes separated from thr sinusoidal lining cells?

Answer 66

By the perisinusoidal space= space of Disse

Question 67

What are the macrophages of the liver called?

Answer 67

Kupffer cells