GI Glands

Question 1

Secretory mechanism: exocytosis

What is the gland classification?

Answer 1

merocrine

Question 2

Secretory mechanism: gland releases product together with a small amount of apical cytoplasm of secretory cell
What is the classification?

Answer 2

Apocrine

Question 3

Secretory mechanism: whole cell

What is the classification?

Answer 3

holocrine

Question 4

What does saliva contain?

Answer 4

proteins, glycoproteins (mucus), ions, water, and IgA

Question 5

What gland produces the majority (70%) of the saliva?

Answer 5

submandibular

Question 6

Which gland secretes amylase-rich saliva?

Answer 6

parotid

Question 7

What are the characteristics of parotid glands?

Answer 7

Serous glands
Plasma cells: Make IgA
Serous acini 
Enzymes: amylase, peroxidase, lysozyme
Antimicrobial proteins: proline-rich, histatins, cystatins, statherin

Question 8

What are the characteristics of sublingual glands?

Answer 8

Mucus gland: mucus acini predominate
Serous cells produce salivary amylase
Branched tubuloalveolar glands
Primary function: lubrication

Question 9

What are the characteristics of submandibular glands?

Answer 9

mixed serous and mucus

Serous demilune: mucous cells close to acinus of intercalated ducts

Question 10

What part of the salivary gland duct is there transport of ions and water?

Answer 10

Striated duct

Question 11

What 3 constituents of saliva does the protective function of the saliva depend on?

Answer 11

lysozyme: attack walls of bacteria
Lactoferrin: chelates iron necessary for bacterial growth
IgA: neutralizes bacteria and viruses

Question 12

What is the function of amylase and lingual lipase?

Answer 12

amylase: initial digestion of carbs

Lingual lipase: hydrolysis of dietary lipids

Question 13

What are the primary targets of rabies and mumps virus? What can this cause

Answer 13

parotid glands
Transmitted in saliva
Complications of mumps: orchitis (lead to sterility) and meningitis
Issue with mumps is the surgery for removal of tumors (facial nerve damage possible)

Question 14

What is the main function of the endocrine pancreas?

Answer 14

Islet of langerhans (2% volume of pancreas) regulates glucose metabolism by hormones secreted into bloodstream

Question 15

What is the functional histologic unit of the exocrine pancreas?

Answer 15

acinus which contains centroacinar cells that are continuous with low cuboidal epithelial lining of intercalated duct

Question 16

What do centroacinar cells secrete?

Answer 16

these cells (duct cells) secrete bicarb solution under stimulation of secretin and secrete mucin

Question 17

What two peptide hormones increase the flow of pancreatic fluid?

Answer 17

CCK and secretin

Question 18

What peptide hormon produced by enteroendocrine cells of duodenal mucosa binds to acinar cells to stimulate release of zymogen?

Answer 18

CCK

Question 19

Brunner’s glands secrete what? What is the purpose?

Answer 19

Bicarb ions and alkaline secretion

Neutralize acidic gastric chyme in duodenal lumen and activate pancreatic digestive enzymes

Question 20

What causes acute pancreatitis?

Answer 20

premature activation of pancreatic enzymes and inactivation of trypsin inhibitor result in autodigestion of pancreatic acini
Usually follows heavy meals or alcohol

Question 21

What are the clinical features of acute pancreatitis?

Answer 21

Severe abdominal pain, nausea, vomiting, rapid elevation of amylase and lipase in serum

Question 22

Where does blood from portal vein and the hepatic artery mix in the liver? Where do they converge?

Answer 22

siusoids of the liver lobules and converge at central venule of liver lobule

Question 23

Central venules converge to form what?

Answer 23

sublobular veins

Question 24

What is the structural and functional unit of the liver?

Answer 24

Hepatic lobule

Question 25

What does the central venule (vein) of the hepatic lobule collect?

Answer 25

Sinusoidal blood containing a mixture of blood supplied by branches of the portal vein and hepatic a

Question 26

What are the 3 types of functional units of the liver?

Answer 26

Classic hepatic lobule: hexagonal surrounding central vein; portal triad at angles Portal lobule: triangular; center is bile duct collecting from 3 hepatic lobules; angles are central veins Liver acinus: blood and bile flow in opposite directions

Question 27

What are small blood vessels between radiating rows of hepatocytes called?

Answer 27

sinusoids

Question 28

What macrophages can be found withing sinusoids? what are the function?

Answer 28

Kupffer cells involved in recycling of old red blood cells

Question 29

What is the characteristic of endothelium that lines liver sinusoids?

Answer 29

fenestrated and lacks continuous basement membrane

Question 30

What is the space between the fenestrated endothelium and the cords called? What extends into this space?

Answer 30

space of disse | microvilli of hepatocytes allowing proteins and other plasma components from sinusoids to be absorbed by hepatocytes

Question 31

What are Ito cells?

Answer 31

hepatic stellate cells located at intervals w/i space of disse Storage sites for fat and vit A

Question 32

What produces bile? Where does bile flow?

Answer 32

hepatocytes Flows in opposite direction to blood and transported through bile canaliculi into canal of Hering and then into bile duct

Question 33

Which side of the hepatocyte extends into the space of disse?

Answer 33

basolateral domain

Question 34

What does the basolateral domain of hepatocytes participate in?

Answer 34

the absorption of blood-born substances like bilirubin, hormones, vit B12, substances to be detoxified Secretion of plasma proteins like albumin fibrinogen, complement proteins

Question 35

What is the functional endocrine and exocrine cell of the liver?

Answer 35

hepatocytes

Question 36

Hepatocytes contain SER, what do the functions of SER include?

Answer 36

synthesis of cholesterol and bile salts glucuronide conjugation of bilirubin, steroids, and drugs breakdown of glycogen detoxification of lipid-soluble drugs

Question 37

What is bile and what does it participate in?

Answer 37

mixture of organic and inorganic substances produced by hepatocyte Participates in excretion of cholesterol, phospholipids, bile salts, conjugated bilirubin and electrolytes

Question 38

What does fat absorption in intestinal lumen depend on?

Answer 38

fat-emulsifying function of bile salts

Question 39

_____ transports IgA to intestinal mucosa

Answer 39

Bile

Question 40

What process is the secretion of bile into the bile canaliculus?

Answer 40

ATP-mediated process

Question 41

Long term consumption of ethanol results in what?

Answer 41

fatty liver; reversible process

Question 42

What is cirrhosis?

Answer 42

collagen proliferation of fibrosis of liver

Question 43

What is hepatocellular carcinoma?

Answer 43

malignant transformation of hepatocytes

Question 44

What are the main functions of gallbladder?

Answer 44

storage, concentration, and release of bile

Question 45

Why do galstones form?

Answer 45

bc of cholesterol and pigments in bile form hard particles Cholesterol stones: yellow-green Pigment: smaller and darker and made up of bilirubin