LECTURE - GI System

Question 1

GI glands have two main functions

Answer 1

• digestion of food

- protection of the GI mucosa

Question 2

acinus

Answer 2

a spherical mass of cells with a lumen at the center

Question 3

mucosa of esophagus

Answer 3

non-keratinized squamous epithelium

Question 4

lamina propria of esophagus

Answer 4

blood vessels, inflammatory cells, mucus glands

Question 5

muscularis mucosa of esophagus

Answer 5

peristalsis

- small layer

Question 6

muscularis propria

Answer 6

bigger muscle layer - responsible for lots of peristalsis

Question 7

submucosa

Answer 7

supportive tissue = mucus glands, blood vessels, nerves

Question 8

synonymous with serosa for esophagus

Answer 8

adventitia (covers esophagus)

• loose connective tissue - lacks true serosa for most of its length
• doesnt need it like colon does for ex (‘floating’)

Question 9

glands in esophagus

Answer 9

• submucosal mucus glands with cuboidal lined ducts running up the luminal surface
• glands resemble salivary and Brunner’s glands
• gastric glands may be metaplastic or just related to location
• can find heterotopic pancreas tissue
• intestinal glands or goblet cells are indicative of metaplasia and Barrett esophagus

Question 10

a mixed endocrine and exocrine organ that both digests food and secretes hormones into the bloodstream

Answer 10

stomach

Question 11

stomach histology

Answer 11

• simple columnar (foveolar epithelium)
• gastric pits
• glands beneath the pits

Question 12

Paneth cells

Answer 12

secrete antimicrobial substances

- mainly small bowel and right colon

Question 13

Brunner’s Glands

Answer 13

• unique to duodenum
• submucosal
• secrete alkaline mucus fluid that neutralizes stomach acid so it doesn’t burn a hole in the duodenum

Question 14

colon

Answer 14

• main function = absorption of water
• consists of long tubular crypts (Crypts of Lieberkuhn)
• goblet cells are abundant

Question 15

protein synthesis in liver

Answer 15

• albumin
• prothrombin
• fibrinogen
• lipoproteins

Question 16

glandular epithelial cancer

Answer 16

adenocarcinoma

Question 17

function of the small bowel

Answer 17

absorption of nutrients

- need massive SA; long and has tiny villi that carpet the lumen

Question 18

surgeries which reduce the length of mal intestine

Answer 18

can lead to problems with maladsorption

- short gut syndrome

Question 19

where are goblet cells found?

Answer 19

throughout small and large bowel

Question 20

two main entities of inflammatory bowel disease

Answer 20

Chron’s disease

Ulcerative colitis

Question 21

Crohn’s disease

Answer 21

• can affect entireity of GI tract

- most typically affects terminal ileum

Question 22

Ulcerative colitis

Answer 22

• limited to colon

- tycially afects rectum and distal colon but can spread contiguously

Question 23

function of the salivary glands

Answer 23

• digestion (amylase)
• lubrication (mucin)
• immunologic (IgA)

Question 24

types of salivary gland secretions

Answer 24

• serous

- mucinous

Question 25

parotid gland

Answer 25

- purely serous - contributes 25% of saliva - branched acinar - secretions contain amylase and IgA

Question 26

serous acini

Answer 26

- watery (pink) secretions = enzymes and Abs | - pyramidal shaped cells with basophilic cytoplasm

Question 27

mucinous acini

Answer 27

- secrete viscous (clear) mucus | - cuboidal to columnar cells with pale pink cytoplasm and oval nnucle towards the base of the cells

Question 28

submandibular gland

Answer 28

- serous and mucinous - 70% of saliva - branched tubuloacinar pattern - serous deminlunes secrete lysozyme

Question 29

lysozyme

Answer 29

the body's natural antimicrobial enzyme

Question 30

sublingual

Answer 30

- mainly mucinous - branched tubuloacinar gland - produces lactoferrin (antimicrobial) - contributes 5% of saliva

Question 31

interlobular, intralobular, intercalated ducts run through this organ

Answer 31

pancreas

Question 32

exocrine pancreas

Answer 32

compound acinar glands - trypsinogen - chymotrypsinogen - carboxypeptidase - ribonuclease - deoxyribonuclease - lipase - amylase - phospholipase A2 - elastase

Question 33

endocrine pancreas

Answer 33

islet of Langerhans - alpha: glucagon - beta: insulin and amylin - delta: somatostatin - epsilon: ghrelin - PP cells (gamma or F): pancreatic polypeptide

Question 34

T or F. similar to pancreas, the liver has both endocrine and exocrine function

Answer 34

T! - each hepatocyte contributes to both functions with no division of labour (UNLIKE pancreas) - so hepatocytes are connected to both the blood supply and bile ducts

Question 35

function of liver

Answer 35

protein synthesis - albumin - prothrombin - fibrinogen - lipoproteins

Question 36

architechture of liver

Answer 36

- divided up into lobules - central vein at center - ptal triad at periphery - between stacks of hepatocytes are sinusoids

Question 37

sinusoids of liver are lined by

Answer 37

Kupffer cells = imobilized macrophages

Question 38

this runs between hepatocytes and carry bile into ducts

Answer 38

bile canaliculi

Question 39

what makes up the portal tracts

Answer 39

- heptic portal vein - hepatic artery - bile duct - sometimes lymphatic vessel

Question 40

T or F. occasionally, more than 1 bile duct is present per portal tract

Answer 40

T!

Question 41

gallbladder

Answer 41

- simple columnar - NO goblet cells - no submucosa - no muscularis mucosa or propria - has muscularis externa