Digestive Glands and Liver Flashcards Preview

A. White- Histology > Digestive Glands and Liver > Flashcards

Flashcards in Digestive Glands and Liver Deck (68):
1

What is the main excretory duct of the pancreas?

Duct of Wirsung

2

What is the accessory duct of the pancreas?

Duct of santorini

3

What type of epithelium is present in the interlobular ducts?

simple columnar epithelium and goblet cells

4

What type of epithelium is found in the intercalated ducts?

Low cuboidal.

The cells also have receptors for secretin, and they secrete water and bicarbonate.

5

What type of glands are acini?

serous glands

6

What type of cells are acinar cells?

pyramidal serous cells.

7

What is found in the apical zone of acinar cells?

precursors of the enzymes in pancreatic juice

Trypsin, chymotrypsin, amylase and lipase

8

What type of epithelium is found in centroacinar cells?

cuboidal epithelium

It is continuous with the epithelium of the intercalated duct.

9

What enzymes does the acinar cell release?

digestive enzymes. It is stimulated by CCK.

10

What type of fluid is released by epithelial cells in response to secretin?

Bicarbonate-rich, alkaline fluid. It is released by the acinar cells.

11

Where are digestive enzymes found?

in vesicles by the Golgi

12

What is the synthesis and secretion of digestive enzymes controlled by?

duodenal enteroendocrine cells.

13

What are digestive enzymes synthesized as?

Inactive proenzymes on RER of acinar cells

14

Bicarbonate ion secretion is regulated by what?

secretin.

Bicarbonate is secreted by duodenal enteroendocrine cells when stimulated by food entering the small intestine.

15

Where does carbon dioxide diffuse out of?

intercalated ducts from the blood.

16

What are the islets of Langerhans?

Endocrine cell aggregations which are interspersed irregularly among the acini.

They include alpha, beta and delta cells

17

What are a-cells?

Fine cytoplasmic granules in the islets of Langerhans that form glucagon.

18

What are b-cells?

cells in the islets of Langerhans that produce insulin.

19

What are D-cells?

cells in the islet of langerhans that secrete somatostatin, which helps control levels of insulin and glucagon.

20

What is the general histological organization of the pancreas?

lobulated, compound tubulo-alveolar gland with both and exocrine and endocrine secretory function.

CT divides the gland into small lobules. The lobules contain blood vessels, lymphatics, nerves and excretory ducts.

21

What is the space of disse?

A region that separates hepatic cells from endothelial cells.

It is active in the transfer between blood and parenchyma

22

What is the space of mall continuous with?

The space of Disse. It drains into lymphatics.

23

Glisson's thin capsule of FECT covers the surface of the parenchyma except for what region?

the diaphragmatic attachment.

24

What is the classic hepatic lobule?

A lobule with a central venule. Portal triads are at the angles.

25

What is a portal lobule?

It has three central venules of adjacent lobules that form a triangle.

Portions of the bile of the three lobules drain into the same bile duct.

26

How many zones are in the liver acinus?

Three zones.

They have hepatic tissue receiving blood from a branch of the hepatic artery conducting blood to opposite central veins.

27

Where is the portal triad?

It it found at angles (corners) of the classic lobule

28

What are the components of the portal triad?

branch of hepatic artery (arteriole)

Branch of portal vein (venule)

Bile duct (ductule)

29

What is found in the cytoplasm of hepatocytes?

glycogen, fat droplets, and pigment granules.

30

What is found in the basolateral domain of a hepatocyte?

microvilli

They are involved in the absorption of blood-borne substances and the secretion of plasma proteins.

31

What is found in the apical domain of a hepatocyte?

A bile canaliculus

32

What is found in the lining of hepatic sinusoids?

Fenestrated endothelial cells

Discontinuous basal lamina

33

What are perisinusoidal cells?

Cells located in the space of disse that store vtamin A.

They also produce collagen fibers and extracellular matrix components.

34

What happens do perisinusoidal cells during cirrhosis?

They transform into myofibroblasts and produce type I collagen.

35

What is the subendothelial space of disse?

space between basal lamina and hepatocytes.

It contains microvilli, collagen, and interstitial fluid that drains into the space of Mall that drains into the lymphatics.

36

What are Kupffer cells?

phatocytc cells derived from monocytes that line hepatic sinusoids.

37

What is the bile canaliculus?

Extracellular canal located between two rows of hepatocytes.

It receives bile from hepatocytes.

38

What is the canal of Hering?

a canal that receives bile from the canaliculus.

It carries bile to the bile ductule.

39

What are the four components of the gallbladder?

Fundus

Body

Neck

Wall

40

What are the three layers of the wall of the gallbladder?

mucosa

muscularis externa

submucosa

41

What type of epithelium is found in the mucosa of the gallbladder?

tall columnar with a striated border

42

What are Rokitansky-Aschoff sinuses?

small regions of the mucosa with extend into muscular and perimuscular layers.

They may indicate pathological change.

43

What is found in the muscularis externa?

Layers of smooth muscle separated by layers of CT

44

What is found in the serosa?

A broad, perimuscular CT coat that is rich in blood and lymphatic vessels and elastic fibers.

45

What are the major ducts found in the gallbladder?

Cystic duct

Hepatic duct

Common bil duct

46

The ducts of the mucosa are lined with what type of epithelium?

Columnar epithelium

47

What are the afferent blood vessels found in the liver?

portal vein

hepatic artery

48

What do branches of the portal vein enter into?

The lobule.

They then empty into the hepatic sinusoids.

49

What do the hepatic sinusoids converge into?

A centeral vein (efferent vessel)

50

What do the central veins unite to form?

A sublobular vein (tributary of the hepatic vein)

51

What are some of the functions of the liver?

Removal of bile

Storage of glycogen

Conversion of fats and proteins to carohydrates

Amino acid deamination

52

What does the liver metabolize and store?

fat

53

What plasma proteins are stored in the liver?

fibrinogen, prothrombin and albumin

54

What essential vitamins does the liver store?

A, D, B2, B3, B4, B12, K

55

The liver serves as a ____ organ.

embryonic hematopoietic

56

The liver also serves as an important organ for ___ metabolism and detoxifying ___

ethanol

drugs, steroids, vitamins A & D, fatty acids and carcinogens.

57

What is the alcohol dehydrogenase pathway?

Ethanol -> acetaldehyde -> acetate

acetaldehyde is also involved in hepatocyte injury

58

What organ produces and secretes hepatic bile?

the liver

59

What are the components of bile?

bile acids

water and electrolytes

cholesterol and phospholipids

pirgments and organic molecules (bilirubin)

60

Bilirubin is formed from what molecule?

Hemoglobin. It is released from damaged RBCs

61

What is hemoglobin phagocytized by?

macrophages.

62

When hemoglobin has been phagocytized by macrophages, what does it split into?

globin and heme

63

What enzyme converts heme into biliverdin?

heme oxygenase

64

Free bilirubin is transported attached to what protein as it travels to liver hepatocytes?

plasma albumin

65

Once free bilirubin is released from plasma albumin, what occurs to it?

It is released within the liver cells and conjugated into bilirubin glucuronids (80%), bilirufin sulfate (10%) and other substances.

66

Where is conjugated bilirubin secreted?

Into the intestine.

67

What is conjugated bilirubin in the intestince converted into?

urobilinogen

68

What are the fates of urobilinogen?

oxidized into excreted products OR
Reabsorbed into the blood and carried back to the liver to be

Reexcreted by the liver OR excreted in the urine.