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Flashcards in Digestive Accessory Organs Deck (66):
1

There are three large salivary glands, found in _______, called the _______, _______, and _______.

pairs; parotids; sub-mandibulars; sub-linguals

2

Salivary gland

Lobated gland encapsulated in CT that invades the glandular elements to form septae that separate the organ into lobules
Parenchyma of each consists of secretory units on a branching duct system, arranged in lobules

3

Salivary secretory units are comprised of three epithelial cell types: _______, _______, and _______.

serous cells; mucous cells; myoepithelial cells

4

Myoepithelial cells

Modified epithelial cells containing actin and myosin that are found in the basal lamina surrounding acini, tubules, and the proximal ends of the duct system
They contract to squeeze the contents of the secretory unit or duct

5

There are three types of ducts:

Intercalated duct
Striated duct
Excretory duct

6

Intercalated duct

Short, intralobular ducts composed of simple cuboidal epithelium that acini and tubules empty their contents into
Merge with other intercalated ducts and empty into striated ducts
Part of the intralobular duct system

7

Striated duct

Intralobular ducts composed of simple columnar epithelium that intercalated ducts empty into
Converge and drain into excretory ducts
Epithelia have basal membrane invaginations and an accumulation of mitochondria (characteristics of ion-transporting cells)

8

Excretory duct

Thick interlobular ducts (found in the septa) composed of stratified cuboidal epithelium that becomes stratified columnar epithelium

Striated ducts empty their contents into excretory ducts

9

Serous acinus

Somewhat basophilic due to its secretory product
Secretes zymogen granules
Watery secretion
Find all over

10

Mucous acinus

Slightly eosinophilic due to its secretory product
Secretes carbohydrate-rich product
Sticky, viscous secretion

11

Demi-lune

Cap of serous cells found on top of mucous acini
Secretes the protein product lysozyme that digests bacterial cell walls

12

The duct cells of acinus ducts can _______ secretions.

modify

13

Simple cuboidal cells of intercalated ducts absorb _______ and secrete _______ to modify secretions.

chloride; bicarbonate

14

Simple columnar cells of striated ducts reabsorb _______ and secrete _______ and _______ to modify secretions.

sodium; potassium; bicarbonate

15

Secretory ducts _______ modify secretions.

don't

16

Parotids

Large, entirely serous glands found on the sides of the face
Stenson's duct deposits saliva in upper part of oral cavity by the second molar
Key gland for oral digestion
Secretes alpha-amylase
Produces IgA

17

Why do the parotids stain basophilic?

All acini are serous

18

IgA produced by the parotids functions to_______.

defend against antigens from food

19

Name the accessory organs of the digestive system.

Salivary glands
Pancreas
Liver
Gallbladder

20

How do you distinguish the parotids from the pancreas?

The pancreas has islets of Langerhans
Facial nerve can sometimes be seen in the parotids

21

Sub-mandibular glands

Gland beneath the base of the mandible
Mixed gland, containing mucous acini, but predominately serous
Produces some saliva

22

Serous cells

Polarized, pyramidal, protein-secreting cells with round nuclei
Contain apical secretory granules
Contain abundant RER at the basal end
Joined together apically by tight junctions
Form a spherical unit called an acini with a very small central lumen

23

Acini

Salivary secretory unit made up of serous cells bound by tight apical junctions in a spherical shape
Has a very small central lumen
Cells secrete enzymes and other proteins

24

Mucous cells

Somewhat columnar cells with a compressed basal nuclei
Contain apical granules with hydrophobic mucins that provide lubricating properties to saliva but cause poor cell staining
Organized into cylindrical tubules

25

Sub-lingual glands

Smallest salivary glands
Located under the tongue
Mostly mucous

26

Saliva

Produce 120 mL in 24 hours
Starts, but doesn't finish digestion of carbohydrates
Defense via IgA, lysozyme
Lubrication of the oral cavity
Lubrication, mixing, and softening of food to aid in swallowing
Dissolve tastant molecules in food that we taste
Buffers via bicarbonate

27

Why doesn't saliva finish digestion of carbohydrates?

Food doesn't stay in the mouth for a long period of time

28

Control of salivary secretion is _______ and depends on both _______ and _______ stimulation.

autonomic; sympathetic; parasympathetic

29

Sympathetic stimulation of salivation

Decreases salivation
Responsible for dry mouth in fight-or-flight response

30

Parasympathetic stimulation of salivation

Increases salivation

31

Pancreas

Elongated, CT-encapsulated gland under the stomach
Consists of three regions: head, body, and tail
Both exocrine and endocrine gland that produces both digestive enzymes and hormones
CT separates the parenchyma into lobules

32

The pancreas has both _______ and _______ functions.

exocrine; endocrine

33

Exocrine function of the pancreas

Produces enzymes, collectively called pancreatic juice that is released as zymogen granules to prevent auto digestion
Duct cells secrete the fluid for pancreatic juice
Secrete bicarbonate and sodium that keep zymogens inactive until they get to the duodenum

34

Endocrine function of the pancreas

Islets of Langerhans scattered through the exocrine pancreas
Consist of A cells, B cells, and D cells
Highly vascularized with many fenestrated capillaries

35

A cells of islets of Langerhans

Alpha α cells
20% of cells
Produces glucagon

36

B cells

Beta β cells
Produce insulin

37

D cells

Delta ∆ cells
Produces somatostatin (pleiotropic)

38

Glucagon

Peptide hormone produced by α cells of the pancreas that raises the glucose concentration in the blood

39

Insulin

Peptide hormone produced by β cells of the pancreas that lowers the glucose concentration in the blood

40

Somatostatin of the pancreas

Peptide hormone produced by ∆ cells of the pancreas that regulates secretion of local insulin and glucagon

41

Pleiotropic

Having two opposite effects

42

_______ can be used to identify α, β, and ∆ cells.

Immunolabeling

43

What makes the zymogen granules of the exocrine pancreas?

Acini cells

44

Exocrine secretion in the pancreas is regulated mainly by two polypeptide hormones produced by enteroendocrine cells of the small intestine called _______ and _______.

secretin; CCK

45

Secretin

Polypeptide hormone produced by enteroendocrine cells of the small intestine
Promotes water and bicarbonate secretion by the duct cells

46

CCK

Cholecystokinin
Polypeptide hormone produced by enteroendocrine cells of the small intestine
Stimulates enzyme secretion by acinar cells

47

Mixed salivary glands have _______ secretory units with both _______ and _______ secretions.

tubuloacinar; serous; mucous

48

What produces the digestive enzymes of the pancreas?

Serous acini (exocrine portion)

49

Pancreatic acini

Consists of serous cells around a very small lumen
No myoepithelial cells
Cells are polarized, with a round basal nuclei and apical zymogen granules (typical of protein-secreting cells)
Each acinus is drained by a short intercalated duct of simple squamous epithelium

50

The initial, lightly-staining cells of pancreatic intercalated ducts are called _______ and are unique to the pancreas.

centroacinar

51

Liver

Encapsulated organ in the URQ (Glisson's capsule made of fibrous CT)
Separated into 2 lobes
Peritoneum on top of capsule

52

What is the function of the liver?

Detoxification of blood
Produces bile salta/acids that emulsify fats for digestion
Metabolizes old RBC, especially bilirubin
Stores glucose
Glycogenolysis (breaks glucose down when needed)
Gluconeogenesis (a.a. to glucose)
Vitamin A and D
Makes proteins

53

Bilirubin

Product of RBC metabolism
Metabolized by the liver

54

What proteins does the liver make?

Albumins (trafficking protein; iron, fats, steroids)
Globulins
Fibrinogen (blood clotting)
Lipoproteins

55

The liver has two types of blood, _______ and _______ blood.

venous; arteriole

56

Venous blood of the liver

75% of blood
Via SI, spleen, and pancreas via hepatic portal vein

57

Arteriole blood of the liver

25% of blood
Via hepatic artery

58

What is the distinguishing feature of the liver?

Cells are arranged into lobules with a central venule and hepatocytes in cords
Every hepatic lobule has a portal triad

59

Portal triad

Every hepatic lobule has one associated with it
Bile ductule branching from a bile duct
Venule branching from the hepatic portal vein
Arteriole branching from the hepatic artery

60

What is the flow of blood from the hepatic triad in the liver?

Central vein --> hepatic portal veins --> inferior vena cava --> heart

61

Blood and bile are never _______.

mixed

62

Hepatocytes

Very large cells of the liver
Many are binucleate
Many are polyploid
Regenerative capabilities
Non-mitotic; replaced by stem cells

63

Gallbladder

Organ that stores bile produced by the liver
Expands and contracts easily
Bile condensates

64

What can happen to the gallbladder if someone is too dehydrated?

The bile can condensate too much and gall stones may form

65

Layers of the gallbladder tube

Modified
Lining of simple columnar epithelium with many microvilli
DOES NOT HAVE a submucosa
Very thick muscularis externa of smooth muscle that runs in different directions
Adventitia where it touches the liver and serosa on free surfaces

66

_______ induces gallbladder contraction.

CCK