Histology of Accessory Digestive Organs Flashcards Preview

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Flashcards in Histology of Accessory Digestive Organs Deck (49)
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1
Q

What are the three main diestive glands (general)?

A
  1. Major salivary glands
  2. Exocrine pancreas: secreting alkaline aqueous and enzymatic product into duodenum
  3. Liver: endocrine and exocrine gland with extensive acces to blood circulation
2
Q

Describe the orgtanization of salivary glands.

A
  • CT capsule with a septa dividing the gland into lobes and smaller lobules
  • Secretory cells are organized into an acinus producing saliva via ANS, myoepithelial cells help release it via ducts
    • Acinus–>intercalated duct–>striated duct–>excretory duct
3
Q

What is the pathway for saliva to flow, and what epithelium makes up each duct?

A
  • Acinus
  • Intercalated duct made of low cuboidal
  • Striated duct made of simple cuboidal to columnar
  • Excretory duct made of simple cuboidal, psuedostratified or stratified cuboidal
4
Q

What is this what does it consist of?

A
  • Parotid gland
  • Acini have serous secretory cells
    • pyramidal cells with a basal nuclei
    • Prominent RER in basal region
    • secretory granules are visible in apical region
5
Q

what is this

A

parotid

6
Q

what is this what does it consist of

A
  • Sublingual gland
  • Mixed but predomiinantly mucous
  • branched tubule alveolar gland
  • lacks a defined capsule but divided into small lobes by CT
  • Intercalated and striated ducts poor developed
7
Q

What is this what does it consist of

A
  • submandibular gland
  • serous ccells predominant but mucous are present
    • serous demilunes
  • intercalated ducts short and striated ducts are longer than those in parotid gland
8
Q

what is this

A

sublingual gland

9
Q

Describe the organization of the pancreas?

A
  • Bulkl of gland is exocrine but endocrine is present also
  • Thin layer of loose CT forms a capsule and divides gland into lobules, neurovasculature and ducts found w/n septa
  • exocrine portion synthesizes secretes enzymes for digestion
    *
10
Q

What is this?

A

pancreas with acinar cells and centroacinar cells

11
Q

What do centroacinar cells do and where are they?

A
  • Found in the pancreas acinar cells
  • Seceret bicarb sodium and water alkalinizes secretions, continuous with low cuboidal epithelium of the intercalated duct
  • Stain lightly
  • (acinar stains intensely)
12
Q

Pancreatic acinar cells?

A

Well developed RER prominent golgi apical domain of zymogen granules

13
Q

Within the pancreatic acinar cells, what do the zymogen granules contain?

A
  • Trypsinogen chymotrypsinogen for protein digestion
  • Amylolytic enzymes for carb digestion
  • LIpase for lipid digestion
  • Deoxyribonuclease ribonuclease for nucleic acid digestion
14
Q

what is this

A

pancreas

15
Q

what is this

A

Pancreas

identify islets of langerhans if confusing with parotid gland

16
Q

What is this

A

pancreas

lookofor faint cytoplasm and dark nucleus, these are centroacinar cells

17
Q

Describe organization of liver

A
  • enclosed within a thin CT capsule lined with mesothelium of visceral peritoneum, which is lacking where the liver attaches directly to another organ
  • Structure of liver varies depending on the functional unit, hepatic lobule, portal lobule and liver acinus
18
Q

What do hepatocytes do?

A
  • Metabolism
  • nutrient storage
  • bile production and secretion
19
Q

How are hepatocytes arragned?

A

NOT acine, they are arranged in cellular cords

liked stacked plates

20
Q

What is the relationship to bile and hepatocytes?

A
  • Hepatocytes secrete bile which is a mix of water bile salts and pigments, phospholipids and electrolytes
  • The bile drains into bile canaliculus which are spaces between hepatocytes
21
Q

What is indicated by the arrows?

A

Bile canaliculi, spaces between hepatocytes for bile collection

22
Q

What is the structure/fxn relationship for hepatic lobule, portal lobule and hepatic acinus?

A
  • Hepatic lobule drains blood from portal vein and hepatic artery to central vein
  • portal lobule drains bile from hepatocytes to bile duct
  • Hepatic acinus supplies oxygen to hepatocytesHo
23
Q

How is liver parenchyma organized?

A
  • Heptic lobules
    • Hepatocytes form irregular plates radiating from a central vein and plates are supported by reticular fibers and separated by sinusoids
24
Q

What does the portal triad include?

A
  • Branch of hepatic artery
  • Branch of portal vein
  • Bile ductules
25
Q

Describe the flow of blood and bile in the hepatic lobule?

A

They flow in opposite directions

26
Q

How do we collect bile?

A
  • Bile collects in bile canaliculi which are interconnected channels formed by hepatocyte plates and tight junctions
  • Bile canaliculi drain into canals of hering once they are full, they are composed of cuboiodal epithelial cells called cholangiocytes
27
Q

Describe the flow of bile.

A
  • Bile canaliculi
  • canals of hering
  • bile ductules
  • merge and enlarge forming right and left hepatic ducts
28
Q

What makes up the Biliary tree?

A
  • Hepatic, cystic and common bile ducts lined with a mucous membrane and a simple columnar epithelium made of cholangiocytes
  • cystic duct has areas with mucous glands
  • Muscularis layer of the ducts becomes hticker near the duodenum forming the sphincter regulating flow into duodenum
29
Q

Describe hepatic sinusoids

A

Anastamosing capillaries that deliver portal and arterial blood to hepatocytes

30
Q

What are Kupffer cells?

A
  • Stellate macrophages w/n endothelium of sinusoids, they are larger than endothelial cells
  • They detect and phagocytose defective RBCs
  • Distinguishes the hepatic sinusoids
31
Q

What are hepatic stellate cells?

A
  • Cells wit hsmall lipid droplets tha store vitamin a and other fat soluble vitamins
32
Q

What is the perisinusoidal space?

A
  • located btw hepatocytes and sinusoidal endothelium and it facilitates uptake and release of nutrients proteins and potenetial toxins
  • creates a potential space for exchange of materials btw blood and hepatocytes
    • Microvilli projectr into the space
    • plasma fills and bathes microvili
    • increase surface area available for materail exchange
33
Q

What is the periportal space?

A

52 min slide65

34
Q

What is the portal lobule?

A
  • Central axis is the bile duct (portal triad)
  • find the portal triad by drawing lines btw 3 central veins to make the portal lobule
  • triangle outlines bile drainage path from adjacent lobules into same bile duct
35
Q

What is the hepatic acinus?

A
  • Diamond shape and occupies parts of adjacent classic lobules
  • find two adjacent central veins with portal triads in between
  • Each zone shows how much blood and nutrients are sent
    • zone 1 most blood
  • This explains distribution of liver damage resulting from ischemia or exposure to toxins, zone 3 will be damaged the most as it already has the least amount of flow
36
Q

What is this and the hallmarks?

A

Gallbladder

  • No muscularis mucosa or submucosa
  • Muscularis with bundles of mm fibers oriented in all directions to allowing emptying of organ
  • External adventitia where it is against liver and serosa where its exposed to peritoneal cavity
37
Q

Describe what is seen

A
  • Rokitansky-Aschoff sinuses, deep divertiula of the mucosa that may extend through the muscularis externa
  • They develop as a result of hyperplasia nad herniation of epithelial cells through the muscularis externa
  • Bacteria may accumulate causing chronic inflammation and increased risk for gallstones
38
Q

Differentiate these.

A

Right is parotid and left is submandibular

39
Q

Differentiate these

A
  • Left: Submandibular glands, you can see the prevalance of serous acini and serous demilunes and few mucous cells
    • ID is intralobular ducts
  • Right: Sublingual glands, you can see a high amount of mucous cells and skeletal muscle
    • ID is intralobular ducts
40
Q

what is this

A

liver hepatic lobule

41
Q

What is this?

A

hepatic lobule

42
Q

Label

A
  • Blue: mucous acini
  • Red: serous acini
  • Duct

Submandibular gland

43
Q

label

A
  1. serous acini
  2. serous demilunes
  3. duct
  4. mucous acini
44
Q

label

A
  • serous demilune
  • mucous acinus
  • duct
45
Q

What is this

A

Sublingual gland

46
Q

What is this

A

Pancreas

47
Q
A

parotid

48
Q
A

Pancreas with islet, duct and acinar tissue

49
Q
A

liver