10/1 Histology!!! Flashcards Preview

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Flashcards in 10/1 Histology!!! Deck (75):
1

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

secretin, and cholecystokinin

2

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

Apocrine

3

cellular mech. of exocrine secretion where entire cell ruptures

Holocrine

4

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

Merocrine

5

secretion into the blood stream

endocrine secretion

6

small saclike smewhat spherical structure

acinar or alveolar

7

long, non sacklike organization of exocrine gland

tubular

8

an inactive enzyme precursor

zymogen

9

what are the exocrine portions of the pancreaus?

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.

10

The endocrine portions of the pancreaus

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

11

what is the histological structure of the pancreus?

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!

12

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

Pancreatic acinar cells

13

what do pancreatic acinar cells store?

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

14

how to stimulate secretion from pancreatic acinar cells

cholecystokinin CCK from DNES cells of the duodenum

15

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

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

16

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

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

17

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

a Cl- / HCO3- exhcanger

18

what regulates the Cl-/HCO3 exchanger in centroacinar cells

CFTR

19

what stimulates the Centroacinar cells (CA) and ducts?

secretin

20

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

Interlobular ducts

21

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

islets of langerhans

22

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

the presence of lots of fenestrated capillaries

23

what is a fenestrated cappilary?

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

24

what is the homone in alpha cells

glucagon

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