10/1 Histology!!! Flashcards

1
Q

what are the two important hormones produced by DNES cells in the duodenum

A

secretin, and cholecystokinin

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2
Q

Cellular mechanism of exocrine secretion where portion of cell pinches off (exmp. mammary gland)

A

Apocrine

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3
Q

cellular mech. of exocrine secretion where entire cell ruptures

A

Holocrine

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4
Q

mech of exocrine where exocytois of vesicles and membrane transport of salt and water (sweat and salivary glands)

A

Merocrine

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5
Q

secretion into the blood stream

A

endocrine secretion

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6
Q

small saclike smewhat spherical structure

A

acinar or alveolar

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7
Q

long, non sacklike organization of exocrine gland

A

tubular

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8
Q

an inactive enzyme precursor

A

zymogen

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9
Q

what are the exocrine portions of the pancreaus?

A

the pancreatic acinus cells that are in a round sac like structure around the intercalated duct and dump right into the ducts to go to the tralobular ducts to the main pancreatic duct etc.

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10
Q

The endocrine portions of the pancreaus

A

not associated with the ducts, and are little islands or Islet of langerhans cells

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11
Q

what is the histological structure of the pancreus?

A

Acinar cells around the ducts with light staining with big nucleus. centroacinar cells (CA) that are light staing cells all by themselfs in the tissue. Intercalated ducts, that are light staining regions without nucleus!

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12
Q

Store zymogens and enzymes in seretory granules: trypsinogen, chymotrypsinogen, carboxypeptidase, amylase, lipase, DNase, RNase

A

Pancreatic acinar cells

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13
Q

what do pancreatic acinar cells store?

A

Store zymogens and enzymes in seretory granules: trypsinogen, chymotrypsinogen, carboxypeptidase, amylase, lipase, DNase, RNase

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14
Q

how to stimulate secretion from pancreatic acinar cells

A

cholecystokinin CCK from DNES cells of the duodenum

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15
Q

what are the ducts from the acinar cells in the pancrius and what ducts do they lead to?

A

intercalated ducts in parenchyma and interlobular in stroma. (no striated ducts like in the salivatory glands

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16
Q

secrete HCO3- rich fluid to keep zymogen inactive by maintaining pH >7.5

A

centroacinar cells (the cells that start the ducts in the acinar cell region) and intercalated ducts

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17
Q

secretion is principally via an exchanger for keeping the pH high in the ducts of the pancreus what is the exchanger

A

a Cl- / HCO3- exhcanger

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18
Q

what regulates the Cl-/HCO3 exchanger in centroacinar cells

A

CFTR

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19
Q

what stimulates the Centroacinar cells (CA) and ducts?

A

secretin

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20
Q

what is the duct that goes through the connective tissue through the pancreus

A

Interlobular ducts

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21
Q

what are the cells that if lost would make the pancreus no longer an endocrine pancreas?

A

islets of langerhans

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22
Q

what gives the islet of langerhans cells the ability to act as an endocrine cell

A

the presence of lots of fenestrated capillaries

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23
Q

what is a fenestrated cappilary?

A

have pores or “windows” in them but not big holes like the sinusoid

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24
Q

what is the homone in alpha cells

A

glucagon

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25
what is the homone in beta cells
insulin
26
what is the hormone secreted by delta cells?
somatostatin
27
inhibit alpha and beta cells
somatostatin
28
what are the % of different islet cells
30% Alpha / 65% Beta / 4% Delta
29
anything which leads to zymogens being activated in the pancreas leads to auto-digestion of pancreatic tissue, inflammation, and intense epigastric pain
Acute pancreatitis
30
cancer more common in females, 3% of all, and poor prognosis
pancreatic carcinomas
31
complex syndrome produced by disruption of insulin signaling, dysregulation of lipid and glucoes levels and serious pathology
Diabetes mellitus
32
the largest gland, involved in regulating blood composition
Liver
33
Synthesis in the liver
blood proteins: albumin, transferrin, fibrinogen, prothrombin, angiotensinogen, etc. (endocrine activity);; lipids and lipoporteins: cholesteerol, fatty acids, LDL, VLDL
34
Storage in the liver
glucose as glycogen lipids as fat droplets vitamins, fat soluble
35
Liver modificaation reactions
oxidation and reducation by cytochrom p450 in SER Conjugaton with glucuronic acid sulfate; methylation (Bilirubin to glucuronide and secreted into bile) several kinds of hormones turned over
36
Liver elimination reactions:
release products back into the blood (leave via urine) | release products into bile, e.g. bilirubin (leave via intestines)
37
Lipid digestion:
bile salts are detergents that emulsify fats and facilitate lipase action (exocrine activity)
38
describe the general microstructure of the liver:
Portal triad: the hepatic artery, the portal vein, and the bile duct are surrounded by connective tissue, and the blood from the portal vein are sent down very porous sinusoids (capilaries) to the terminal hepatic venule (central vein). as the blood goes down it goes past plates of hepatocytes that are creating bile and pushing it back the other way to the bile ducts.
39
what is a kupffer cell?
a macrophage resident in the liver to act on any pathogens coming from the GI system
40
the liver Acinus model describes 3 zones, what changes as you move from zone to zone what are the zones and what do they do?
these are the zones through the hepatic sinusoid where zone 1 has freshest blood, biggest mitochondria, most active glucuronidation, most active endocytosis, most lysosomes (metal deposits) highest regenerative activity!. Zone three you do the oxidation/reduciton reactions (most P450), and Fat deposited here most Zone 2 is intermediate!
41
why would the acinus model of the liver be useful for clinician
gives an ability to classify damage by location and guesse what type of damage is taking place and what might be the progression of the disease
42
the histology of the liver
Portal triad surrounded by alot of hepatocyts, and then an associated terminal hepatic vein, but no nice structure!
43
how do we prevent bile from leaking into the liver and damaging hepatocytes?
terminal bars around the cells of the bile duct create tight junctions!
44
how can we identify bile duct/ hepatic artery/ and portal vein
BD: terminal bars around a lumen (light cells) HA: muscular smooth muscle cells surrounding a lumen Pv: the squished snake lumen with association of the other two
45
how can we identify the hepatic venule?
a large lumen with no other associated vein or artery or ducts
46
describe the structure of the hepatocytes
they have tight junctions supported by desmosomes, with bile ducts between the cells, below they have microvilli, then space of disse and then the endothelium with lots of pores between to allow lots of exchange
47
what is the space between the hepatocytes where blood flows?
sinusoids
48
the opening between hepatic cells that carry bile
bile canaliculus
49
the cells the can acutally cull the blood cells if the spleen is removed
Kepffer cells
50
Store fat and fat soluble vitamins (like A and retinol)
Hepatic stellate cells, lipocytes, fat cells, cells of Ito, Vitamin A cells, interstitual cells
51
where are the hepatic stellate cells?
in the space of Disse
52
what happens if you have liver damage to the hepatic stellate cells?
they can transform into myofibroblasts and synthesize collagen after liver damage
53
what could contribute to fibrosis of the liver (cellular component)
hepatic stellate cells synthesizing too much collagen and other extracellular molecules
54
what could lead to portal hypoertension (cellular component)
Hepatic stellate cells as myofibroblasts express smooth muscle actin and can contract!
55
what could lead to dysregulation of retinol metabolism
reductinon in lipid storage in hepatic stellate cells
56
looks like little black dots inbetween hepatic cells
bile canaliculi
57
what does the gall bladder epithelium do?
sodium and water recovery, and bile concentration. | basolateral Na,K-ATPase to do this
58
bile is recyled in this type of recirculation
interohepatic recirculation
59
what else would follow the enterohepatic recirculation besides bile?
anything that has affinity for both fat and water
60
stimulates bile flow and induces contracaion of gall bladder, and relax the hepatopancreatic sphincter in the duodenum
CCK
61
causes bile ducts to secrete bicarbonate into bile
secretin
62
gall bladder inflammation
cholecystitis
63
inflammation of the liver
hepatits
64
prolonged serious inflammation, destruction of hepatocytes, and activation of myofibroblasts from stellate cells lead to excess collagen and this is called:
fibrosis
65
extensive fibrosis and disorganized regeneration leads to general dysfunction
cirrhosis
66
what happens in cirrhosis
blood flow decreases, impairing addition and removal of blood components lack of flow produces portal hypertenstion, backpressure in venous system and asites (fluid in abdomen etc.)
67
blockage of bile flow:
cholestasis
68
what is cholestais do?
bile is a detergent that can dissolve cells, leading to serious liver damage
69
what if bile leaks into the blood?
yellow the skin etc. to create jaundice
70
what are some special functions of duodenum?
absorptive colomnar cells; Enteroendocrine (DNES) cells; Brunner's Glands;
71
what do the absorptive columnar cells in duodenum do?
enterocytes produce enterokinase, which activates trypsinogen and secrete HCO3- to protect agains acid coming form the stomach
72
what do the DNES cells make?
secretin and CCK
73
what about brunners glands?
found in the sumbucosa of duodenum, produce mucus to protect the duodenum surface.
74
Secretion onto a free surface (usually, but not always via a duct)
Exocrine
75
Types of glands that can be associated with a duct
simple tubular or acinar; branched acinar compound tubular or acinar compound tubuloacinar gland