Exam 3 - Accessory Glands of the Digestive System Flashcards
1
Q
Function of accessory glands
A
aid in the digestion of food stuffs
2
Q
Accessory glands are inside of outside of alimentary canal?
A
Outside
3
Q
Accessory glands are connected via:
A
Ducts
4
Q
Examples of accessory glands
A
- salivary glands
- pancreas
- liver
- gallbladder
5
Q
Is the pancreas retro or intra peritoneal?
A
Retroperitoneal
6
Q
4 regions of the pancreas
A
- uncinate process
- head
- body
- tail
7
Q
Pancreas mass
A
~ 150g
8
Q
What forms the septa that subdivides the pancreas gland into lobules?
A
Flimsy CT capsule
9
Q
Pancreas contains what kind of glands?
A
compound tubuloalveolar gland
10
Q
Intraperitoneal organ
A
Almost totally covered with visceral peritoneum
11
Q
Retroperitoneal organs
A
Lies behind the peritoneum and are only partially covered with visceral peritoneum
12
Q
Organs within the peritoneum are:
A
Suspended
13
Q
Outermost layer of the alimentary canal is either ____ or ____
A
Serosa or adventitia
14
Q
Intraperitoneal regions of the alimentary canal possess a ____
A
Serosa
15
Q
Serosa consists of a connective tissue covered by a _____ which ____ during digestive movements
A
Mesothelium; reduces frictional forces
16
Q
Regions that are firmly attached to surrounding structures by connective tissue fibers possess ____
A
Adventitia
17
Q
Pancreas is a ____ gland containing:
A
Mixed; exocrine and endocrine glands
18
Q
Exocrine gland portion of the pancreas contain ____ which produce:
A
acini; digestive enzymes and bicarbonate rich serous fluid
19
Q
Endocrine glands in the pancreas are found as ____ which secrete ____
A
Islets; hormones (such as insulin and glucagon)
20
Q
Exocrine portion of pancreas secretes ___ mL of buffer fluid a day and ____ enzymes
A
1200; digestive
21
Q
In the exocrine pancreas, there are ____ cells per oval acinus and ___ centroacinar cells that form the border of the lumen
A
40-50 cells; 3-4
22
Q
Exocrine pancreas: course of the ducts into the opening of the duodenum
A
- intercalated ducts
- intralobular ducts
- interlobular ducts
- main pancreatic duct
- joins the common bile duct
- opens into duodenum
23
Q
At the intercalated duct of the exocrine pancreas, cells switch from ___ to ____
A
Simple squamous to simple cuboidal
24
Q
Pancreatic acinar cell has what receptors?
A
- cholecystokinin
- acetylcholine
25
Pancreatic centroacinar cells have what receptors?
- secretin
- acetylcholine? (maybe)
26
Zymogen granules are contained in what pancreatic cell and in what area?
Pancreatic acinar cell; towards lumen of acinus
27
Secretory portion of exocrine pancreas is made up of what cells?
Pancreatic acinar cells
28
Duct portion of exocrine pancreas is made up of what cells?
Centroacinar cells
29
Cholecystokinin is released from:
I-cells in duodenum and jejunum
30
What stimuli cause release of cholecystokinin?
- fatty acids or monoglycerides
- peptides and single amino acids
- acid
31
Cholecystokinin is a potent stimulator of ____ secretion
Proenzyme
32
____ stimulates emptying of gallbladder and inhibits gastric emptying
Cholecystokinin
33
Cholecystokinin is how many amino acids long?
33 amino acids (small peptide molecule)
34
Secretion of exocrine pancreas is enzyme ____
Rich (digestive enzymes, proenzymes, trypsin inhibitor)
35
Secretin is released from:
S-cells of duodenal mucosa
36
Stimuli for release of secretin
- acid in duodenum (pH < 4.5)
- fatty acids in duodenum
37
Physiological effects of secretin
- stimulates pancreatic and bile duct bicarbonate secretion
- inhibits gastric acid secretion
38
True or false: enzyme-rich and enzyme poor secretions are regulated separately
True - but can be released at different times or concomitantly
39
Mechanism of bicarbonate (alkaline) production
1. CO2 combines with H2O in presence of carbonic anhydrase
2. Carbonic acid dissociates into HCO3- and H+ ions
3. H+ ions transported in exchange for Na
4. HCO3- moves out of cell in exchange for Cl-
5. Rate of HCO3- secretion is dependent upon luminal Cl- concentration
6. Na+ moves down electrochemical gradient
7. Water moves into lumen to establish osmotic equilibrium
40
____ acts to open Cl- channels (CFTR) and thus increase secretion of bicarbonate
Secretin
41
Most powerful stimulus for HCOe- secretion is ____
Secretin
42
Secretin activates adenylyl cyclase with raises ____, stimulates ____, and phosphorylates ____
cAMP concentration; protein kinase A; CFTR
43
CFTR
Cystic fibrosis transmembrane regulator
44
CFTR is a ____ channel
Cl-
45
Secretin induced bicarbonate secretion neutralizes acidic chyme in order to:
Create optimal conditions (pH 7-8) for digestive enzymes
46
Main cells of endocrine pancreas
Islets of Langerhans
47
Where are islets of langerhans located?
- scattered among acini
- greater number in tail (1 million islets/pancreas)
48
Are islets of langerhans richly or poorly vascularized?
Richly
49
Name the different islet cells
- beta cell
- alpha cell
- delta cell
- G cell
- PP/F cell
50
Pancreatic beta cell secretes:
Insulin (6000 Da)
51
Pancreatic alpha cell secretes:
Glucagon (3500 Da)
52
Pancreatic delta cell secretes:
Somatostatin
53
Functions of somatostatin
- paracrine: inhibits hormone release
- endocrine: reduces contractions of alimentary tract and gallbladder smooth muscles
54
Pancreatic G cell secretes:
Gastrin (2000 Da)
55
Function of gastrin
Stimulates production of hydrochloric acid by parietal cells of stomach
56
Lobes of liver
Right lobe (larger) and left lobe
57
Right and left lobes of the liver are separated by:
Falciform ligament
58
Largest gland in the body
Liver (1500 g)
59
Where is the liver located in the abdominal cavity?
upper right quadrant
60
The liver has both ___ and ___ functions
Endocrine and exocrine
61
What cells are responsible for both exocrine and endocrine functions in liver?
Hepatocytes
62
____ synthesizes blood proteins and maintains blood glucose
Liver
63
____ is responsible for deamination of amino acids
Liver
64
What organ is responsible for detoxification of drugs and toxins?
Liver
65
Vitamin A is stored in the:
Liver
66
____ metabolizes chylomicrons
Liver
67
The liver manufactures:
Bile
68
True or false: the liver has a dual blood supply
True (hepatic artery and portal vein)
69
Hepatic artery
Brings oxygenated blood from the heart to liver
70
Portal vein
Brings nutrient rich blood from intestines to liver
71
Liver lobule contains ____ arrangement of hepatocytes which contains ____ in the middle and ___ at the periphery
Hexagonal; central vein; portal triads
72
Portal triad contains:
- hepatic artery
- portal vein
- bile duct
73
Central vein of liver lobule follows the ___ axis
Longitudinal
74
Initial branch of hepatic vein
Central vein
75
Hepatocytes within a liver lobule are arranged like _____, forming _____ plates and are separated by large vascular spaces called ____
spokes on a wheel; anastomosing, fenestrated plates; sinusoids
76
Blood from the portal vein and hepatic artery mix in ____
Sinusoids
77
Three types of liver lobules
- classical
- Hepatic acinus
- portal lobule
78
In a classic lobule, blood flows from the ___ to the ___
Periphery to center
79
In a classic lobule, bile enters into ____ and flows to the _____ of the lobule to the _____
bile canaliculi; periphery; interlobular bile ducts
80
In a portal lobule, bile goes to the ___ which is unlike acini of most glands
Periphery
81
All hepatocytes that deliver their bile to a particular interlobular bile duct constitute a:
Lobule
82
Triangular region whose center is the portal triad and three imaginary lines connecting 3 central veins
Portal lobule
83
Liver acinus aka:
Acinus of Rappaport
84
___ is based on blood flow from distributing arteriole
Liver acinus
85
Zone 1 of liver acinus is _____ and zone 3 of liver acinus is ____
Richest in oxygen; oxygen poor
86
Describe components of hepatocyte
- large
- organelle rich (free ribosomes, RER, golgi, mitochondria)
- has proteins for secretion
- maintains blood glucose
87
What cell types makes bile?
Hepatocyte
88
Components of bile
- water
- bile salts
- phospholipids
- cholesterol
- bile pigments
- IgA
89
Tauricholic acid and glycocholic acid are examples of:
Bile salts
90
What are the two stages of bile secretion?
1. bile salts, cholesterol, organic constituents enter hepatocytes and stimulate bile secretion
2. secretin stimulates addition of watery solution of sodium bicarbonate to bile
91
Where is bile concentrated and stored?
Gallbladder
92
Function of bile
Emulsification of fats
93
Resident macrophages in the liver are called:
Kupffer cells
94
Where is the lateral domain of hepatocytes?
between 2 connecting hepatic cells, form bile canaliculi
95
Where is the sinusoidal domain of hepatocytes?
portion of hepatocyte facing sinusoid
96
What type of epithelium is in the gallbladder?
Simple columnar epithelium with microvilli
97
What are the layers of the gall bladder from inside to outside?
- Simple columnar epithelium
- lamina propria
- smooth oblique muscle layer
- adventitia or serosa
| No muscularis mucosa or submucosa
98
Structure of gall bladder when empty
Numerous deep mucosal folds (helps it contract and distend)
99
Sphincter of Oddi
Sphincter that controls bile deposition into duodenum
100
The Sphincter of Oddi must be in a ____ position for the bile to be able to enter the gall bladder
Closed - bile backs up the common bile duct/cystic duct to enter gall bladder
101
Bile release from the gall bladder can be stimulated by:
- cholecystokinin
- acetylcholine
102
Cholecystokinin effects on gall bladder
- causes gall bladder to contract
- Sphincter of Oddi muscles relax
- injects bile into lumen of duodenum
103
Acetylcholine effects on gall bladder
Stimulates contraction
104
Mesothelium of the serosa is covered by:
Simple squamous epithelium
