Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI > Accessory GI histology > Flashcards

Accessory GI histology Flashcards

1
Q

What are the features of the pancreatic acinar gland seen by light microscopy?

A

compound acinar gland cells with branching ducts, pyramidal cells arranged around a central lumen, round nucleus with prominent nucleolus- actively producing a product, basophilic cytoplasm with acidophilic zymogen granules (protein rich product)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the features of the pancreatic acinar gland seen by electron microscopy?

A

many free polyribosomes and RER in basal cytoplasm, prominent Golgi complex with many small vessicles on cis-face and developing zymogen granules on trans-face, acini surrounded by unfenestrated capillaries on basal surface of acinus cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the features of the intercalated ducts in the pancreas?

A

between secretory portion and intralobular ducts, centroacinar cells (unique to pancreas, the intercalated duct has push into acinus), low cuboidal to squamous cells, nuclei surrounded by pale staining cytoplasm, secrete HCO3, Na, and H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the features of the intralobular ducts in the pancreas?

A

cuboidal epithelium to low columnar, secretes large volume of HCO3 rich fluid, lacks striated ducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the features of the interlobular ducts in the pancreas?

A

abundance of CT surrounding, low columnar to high columnar, actively transport H2O and HCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the features of the main pancreatic duct?

A

joins bile duct unite to form single duct, enter into duodenum at the hepatopancreatic ampulla, lined by simple tall columnar cells, runs the length of the pancreas, dumps into the second part of duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the make up of the secretions of the acinar cells?

A

digestive enzymes and proenzymes; trypsinogen, chymotryspinogen, elastase, carboxypeptidase, ribonucleases, phospholipase, amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What controls the secretions of the acinar cells?

A

neural control predominates- vagus, cholinergic neurons increase secretion, hormonal control mostly CCK, increases secretion of a fluid rich in proenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the make up of the secretions of the centroacinar cells and intercalated ducts?

A

release HCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What controls the secretions of the centroacinar cells and intercalated ducts?

A

hormonal control predominates, mainly secretin which increases secretion of a fluid with poor enzyme activity but rich in bicarbonate ion; neural control vagus and cholinergic neurons increase secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the endocrine portion of pancreas do?

A

synthesizes and secretes hormones (insulin and glucagon) which regulate metabolism of glucose, lipids and proteins; cells in the islets of langerhans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the features of the islets of Langerhans?

A

scattered among the acini, aggregations of cells enclosed in reticular fibers, penetrated by fenestrated capillaries, more numerous in body and tail of gland, type of cells in islets not identifiable by routine histological preparations, lack of collagen, composed mostly of alpha, beta and delta cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What do the beta cells do, where are they found and what percent of the islets do they make up?

A

secrete insulin; found in the center of the islet, 70% of islet cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do the alpha cells do, where are they found and what percent of the islets do they make up?

A

secrete glucagon, found at periphery, 15-20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do the delta cells do, where are they found and what percent of the islets do they make up?

A

secrete somatostatin and perhaps gastrin, peripheral location, 5-10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do other hormone secreting cells do and what percent of the islets do they make up?

A

pancreatic polypeptide, 5-10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do autonomic fibers augment hormonal responses in the endocrine portion of the pancreas?

A

acetylcholine augments insulin and glucagon release; noradrenaline inhibits glucose-induced insulin release, stimulates glucagon release

18
Q

what is a liver sinusoid?

A

irregular, dilated spaces lined with fenestrated endothelial cells (form a sieve)

19
Q

What are inlet venules?

A

small venules empty into sinusoid

20
Q

Where are distributing veins in the liver?

A

periphery of lobule

21
Q

Where are central veins in the liver?

A

terminal hepatic venule

22
Q

Where are hepatic veins in the liver?

A

between sublobular vein and inferior vena cava

23
Q

Where is the hepatic artery in the liver?

A

brings oxygenated blood to interlobular arterioles (portal arterioles) then to distributing arteriole, inlet arteriole, sinusoid

24
Q

What is the structural organization of the portal triads?

A

contain preterminal branches of portal vein and hepatic artery; also contains small collecting duct of biliary system, lymphatics

25
Q

What is the structural organization of the liver sinusoid?

A

irregular shape blood vessel, lined with fenestrated endothelial cells, kupffer cells line sinusoids (macrophages)

26
Q

What is the structural organization of the space of disse?

A

perisinusoidal space- btwn sinusoidal endothelium and hepatocytes, site of nutrient, waste and hormone exchange between blood and hepatocytes, Ito cells (stellate cells)

27
Q

What is the structural organization of the bile canaliculi?

A

modification of plasma membrane of hepatocytes; smallest branch of biliary tree, tubular spaces created by adjoining hepatocyte plasma membranes, forming interconnecting rings around hepatocytes which feed into larger channels to the ducts; flow of bile center to periphery, tight junctions between cells on either side of canaliculi

28
Q

What is the function of the Ito cells?

A

store fat, vitamin A, and for some pathological conditions secrete collagen III and I (fibrosis process), thought to be stem cells

29
Q

What makes up the hepatocyte surfaces?

A

perisinusoidal space (like basal portions of other glands), lateral in contact with other hepatocytes, like lateral membranes of other epithelial cells, bile canaliculus- equivalent to apical surface in other cells

30
Q

What is the cellular make up of hepatocytes?

A

80% of cells in liver are hepatocytes, diversity of organelles and inclusions reflect diversity of function; inclusions of glycogen and lipid droplets; SER, RER, Golgi, mitochondria, lysosomes, peroxisomes

31
Q

What is the function of hepatocytes with a well developed SERs?

A

cholesterol synthesis, conjugation of bile salts, detoxification (oxidation, methylation, conjugation) MFO (steroids, barbiturates, antihistamines, anticoagulants)

32
Q

What is the function of hepatocytes with a well developed RER and golgi?

A

protein synthesis, plasma proteins, (albumin, Prothrombin, fibrinogen) lipoproteins (VLDL)

33
Q

What is the function of hepatocytes with a well developed lysosomes?

A

pigment granules, old cytoplasmic organelles

34
Q

What is the function of hepatocytes with a well developed peroxisomes?

A

oxidation reactions, hydrogen peroxide (purine metabolism, lipid metabolism, gluconeogenesis)

35
Q

What are the features of the classic liver lobule model?

A

polygonal/hexagonal shape, central vein is axis, peripheral landmark are portal areas, blood flow from periphery to center central vein, bile flow is from center to periphery, emphasis on endocrine function

36
Q

What are the features of the portal lobule model?

A

triangular /wedge shape, portal area (interlobular duct) is axis, peripheral landmark is three central veins, blood flow is from center to periphery, bile flow is from periphery to center, emphasis is on exocrine function

37
Q

What are the features of the liver acinus model?

A

oval to diamond shaped, distributing vein is axis, peripheral landmark are two central vein, blood flow center (distributing vein to periphery), bile flow from periphery to center, emphasis is on zones (relationship between blood supply and metabolism)

38
Q

What are the features of the mucosal layer of the gall bladder?

A

deep folds; tall simple columnar cells with microvilli and long primary cilium that senses biliary flow, apical junctional complexes, apical and basal concentration of mitochondria, lateral plications (Na/K ATPase), lamina propria with fenestrated capillaries, no muscularis mucosa nor submucosa, or lymyphatics

39
Q

What are the features of the muscularis externa?

A

randomly oriented layers of smooth muscle, contraction induced by CKK

40
Q

What are the features of the adventitia and serosa?

A

thick layer of dense connective tissue, contains blood vessels, lymphatics, adipose tissue, elastic fibers

GI (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions