Functions of the Pancreas Flashcards
1
Q
What is the nutrient associated with the mouth?
A
Carbohydrates
2
Q
What is the enzyme that breaks down carbohydrates? What is its action like?
A
Salaivary Amylase. begins the digestion in the stomach
3
Q
What is the nutrient associated with the stomach?
A
Protein
4
Q
What is the enzyme of the stomach, and what is its action?
A
Denatures protein
5
Q
What are the nutrients associated with the pancreas?
A
Lipid
Carbohydrate
Protein
6
Q
What are the enzymes of the pancreas? (6)
A
Pepsin
Gastric lipase
Pancreatic amylase
Trypsinogen
Chymotrypsinogen
Procarboxypeptidase
7
Q
What is trypsinogen converted into?
A
Trypsin
8
Q
What is chymotrypsinogen converted into?
A
Chymotrypsin
9
Q
What is procarboxypeptidase converted into?
A
Carboxypeptidase
10
Q
What is the function of pepsin?
A
Begins the hydrolysis of polypetides
11
Q
What is the function of gastric lipase?
A
Begins digestion of lipids
12
Q
What is the function of the pancreatic amylase?
A
Digestion of starch
13
Q
What is the function of trypsin?
A
An enzyme that is activated in the small intestine that catalyzes the hydrolysis of proteins to form smaller polypeptide units
14
Q
What is the function of of chymotrypsin?
A
A protein enzyme activated in the small intestine that catlyzes the hydrolysis of proteins into polypeptides and amino acids
15
Q
What is the function of carboxypeptidase?
A
A protein enzyme that hydrolyzes the carboxy end of a peptide release the last amino acid in the peptide chain
16
Q
What are the nutrients of the small intestine?
A
Lipid
Carbohydrate
Protein
17
Q
What are the enzymes of the small intestine?
A
Pancraetic lipase
Sucrase
Maltase
Lactase
Dipeptidase
Tripeptidase
Lipase
18
Q
What is the function of the pancreatic lipase?
A
Digests triglycerides
19
Q
What is the function of the sucrase?
A
Digests sucrose
20
Q
What is the function of maltase?
A
Digests maltose
21
Q
What is the function of lactase?
A
DIgests lactose
22
Q
What is the function of dipeptidase?
A
Digests dipeptides
23
Q
What is the function of tripeptidase?
A
Digests tripeptides
24
Q
What is the function of lipase?
A
Digests monoglycerides
25
What is the pancreas?
A gland organ in the digestive and endocrine systems
26
What is the main characteristic of the pancreas?
It is both an exocrine and endocrine organ
27
What is meant by the fact that the pancreas is an endocrine organ?
Secretes products directly into the bloodstream
28
What are the hormones that the endocrine part of the pancreas produces?
Insulin, glucoagon and somatostatin
29
What is meant by the fact that the pancreas is an exocrine organ?
It secretes substances into a ductal system
30
What is the function of the exocrine part of the pancreas?
Secretes pancreatic juice containing digestive enzymes that pass to the small intestine
31
What is the function of the enzymes secreted by the exocrine part of the pancreas?
Help in further breakdown of the carbohydrates, fat & proteins
32
What % of the pancreas do the endocrine cells make?
1%, they are observed as Islets of Langerhans
33
What are the different kinds of endocrine cells?
Alpha
Beta
Delta
F
34
What do alpha cells secrete?
Glucagon
35
What do beta cells secrete?
Insulin
36
What do delta cells secrete?
Human Growth Hormone
Inhibiting Hormone
37
What is inhibiting hormone?
Inhibit secretion of both glucagon and insulin and slows rate of nutrient absorption
38
What do F cells secrete?
Pancreatic polypeptide
39
What is the function of pancreatic polypetide?
Inhibit secretion of digestive enzymes
Inhibit contraction of the gallbladder
40
What is the pancreatic secretion?
An alkaline liquid secreted by the pancreas, which contains a variety of enzymes
41
What is the composition of pancreatic secretion?
The first component and second component
42
What is the first component of the composition of pancreatic secretion?
A solution of bicarbonate, Na+, K+ and water emitted by epithelial cells that line the pancreatic ducts
43
What is the purpose of the alkaline solution of the pancreatic secretion?
To help neutralize stomach acid so that the digestive enzymes can work more effectively
44
What are the enzymes in the enzymatic component of the pancreatic secretion?
Trypsinogen
Chymotrypsinogen
Carboxypeptidase
Pancreatic amylase
Pancreatic lipases
Deoxyribonucleases
Ribonucleases
45
What is the second component of pancreatic secretion?
The enzymatic component which includes multiple enzymes
46
What is the reaction between water and carbon dioxide catalysed by in the bicarbonate ion production?
Carbonic anhydrase, it forms carbonic acid
47
What happens to carbonic acid in the bicarbonate ion production process?
Carbonic acid dissociates into hydrogen ions and bicarnate ions
48
What is the result of the movement of HCO3- and Na+ into the lumen?
This causes an osmotic gradient, which causes the water to move from the blood
49
The complete digestion of food requires what?
Both pancreatic and brush border enzymes
50
What are most pancreatic enzymes produced as?
Zymogens
51
What is the function of enterokinase?
Converts trypsinogen into trypsin
52
What happens when trypsin is activated by enterokinase?
Triggers the activation of other pancreatic enzymes
53
What is the function of the pancreatic trypsin inhibitor?
It attaches to trypsin and inhibits its activity in the pancreas
54
What is the hormonal regulation of pancreatic secretion?
Secretin
CCK
Vasoactive Intestinal Peptide
55
When is secretin released in regards to pancreatic secretions?
When the acidic chyme from the stomach enters the duodenum, the acid stimulates the duodenal mucosal cells to release secretin
56
What is the function of secretin in regards to pancreatic secretion regulation?
Stimulates the centroacinar (ductal) cells of the pancreas to release bicarbonate-rich fluid, which neutralizes the acidic chyme, providing suitable pH for th action of digestive enzymes
57
What causes the release of CCK in from the pancreas?
Fats and partially digested proteins in the duodenum stimulate the release of CCK
58
What is the function of CCK in regard to pancreatic secretion regulation?
Stimulate acinar cells of the pancreas to release digestive enzymes
Slows down gastric emptying, ensuring that the duodenum is not overloaded with chyme
Inducing the gallbladder to contract and release bile into the duodenum, aiding in fat digestion
59
What is the function of VIP in regards to pancreatic secretion regulation?
Inducing watery pancreatic secretions
60
What is the nervous regulation of the pancreatic secretion?
Vagal stimulation
61
How is pancreatic secretion regulated by the vagal nerve?
Stimulate the pancreas to secrete its digestive enzymes during the cephalic and gastric phases of digestion
62
What is the difference between the vagal and the nervous regulation of pancreatic secretion?
Vagal regulation has a DIRECT effect on the pancreatic cells (through acetylcholine)
63
What are cephalic and gastric phases triggered by?
Sight, smell and presence of food in the stomach
64
What are the phases of pancreatic secretion?
Same as gastric secretion: cephalic, gastric and intestinal
65
Explain the cephalic phase of pancreatic regulation?
Conditioned or unconditioned reflex --> vagus nerve --> pancreas (secretion of pancreatic juice)
66
What % of pancreatic juice is secreted through the gastric phase?
About 20%
67
What are the conditioned reflex of the gastric phase?
Sight, smell, thought, and hearing of food
68
What is the unconditioned reflex if the gastric phase?
The taste of food (food in the mouth)
69
Is the cephalic phase of the pancreatic secretion nervous or hormonal?
Nervous
70
What is the gastric phase of pancreatic secretion like?
Bolus in stomach --> Gastric secretion --> Gatrin (causing stretching of the stomach) --> Pancreas (secretion of pancreatic juice)
71
What % of the pancreatic secretion is due to the gastric phase?
5 to 10%
72
Is the gastric phase of the pancreatic secretion hormonal or nervous?
Hormonal
73
What is the intestinal phase of the pancreatic secretion like?
Chyme in the intestine --> Secretin --> Pancreas secretion (rich in bicarbonate)
Chyme in intestine --> CCK--> Pancreas secretion (rich in enzyme secretion)
74
What % of the pancreatic secretion does the intestinal phase account for?
Majority of the secretion (about 80%) specifically because of secretin
75
What is the effect of CCK on the gallbaldder?
Contraction
76
What is the effect of CCK on the pancreas?
Acinar secretion
77
What is the effect of CCK on the stomach?
Reduced emptying
78
What is the effect of CCK on the sphincter of Oddi?
Relaxation, remains open
79
What are intestinal secretions?
Clear to pale yellow watery secretions from the glands lining the small intestine walls
80
What are the components of the intestinal secretions?
Mucin
Water and electrolytes
Enzymes
81
Where is mucin secreted from?
Goblet cells inter-spersed throughout the entire length of the intestine
82
What is the function of mucin?
Provides lubrication and protection for the intestinal lining against mechanical and chemical stress of digestion
Also plays a role in protecting the lining from potential pathogens
83
What are the enzymes present in intestinal secretions?
Peptidase
Sucrase, maltase, latase
Lipase
Enterokinase
Somatostatin
CCK
Secretin
84
What is the function of peptidase in intestinal secretions?
Breaks down peptides into amino acids
85
What is the purpose of sucrase, maltase, and lactase?
Break down disaccharides into monosaccharides
86
What is the function of lipase?
Breaks down fatty acids and glycerol
87
What is the function of enterokinase?
Converts trypsinogen to trypsin
88
What is the function of somatostatin?
Inhibits acid secretion by stomach
89
What are functions of CCK?
Stimulate pancreas to release enzymes in pancreatic juice
Stimulates gallbladder to release bile
90
What is the function of secretin?
Stimulates pancreas to release bicarbonate ions in pancreatic juice
91
In what kind of environment is trypsinogen converted into trypsin?
Alkaline environments
92
What are Brunners glands?
They are glands that are located in the first few cm of the duodenumm, where pancreatic and bile juices empty into the duodenum
They are NOT found in the ileum
93
What is the secretory product of Brunners glands?
Slightly alkaline highly viscous fluid containing mucus
94
What is the function of Brunners glands?
Physiologic anti-acid function by coating the duodenal epithelium, protecting it from the acid chyme of the stomach
95
What are the crypts of Lieberkuhn?
The epithelia of the villi extend down into the lamina propria and form crypts (chambers)
96
What are the kinds of cells that reside inside the crypts? (5)
Enterocytes
Goblet cells
Paneth cells
Enterochromaffin cells
Endocrine cells
97
What do enetrocytes produce?
Digestive enzymes
98
What do goblet cells produce?
Mucus
99
What do Panneth cells produce?
Glycoproteins, Immunogloblins, Lysozymes
100
What do enterochromaffin cells produce?
Seretonin
101
What do endocrine cells produce?
GI hormones: secretin, CCK, VIP, GIP
102
What are enterocytes?
Cells that line up the small intestine and secrete water and electrolytes into the lumen aid digestion and facilitate chyme movement
103
What is the function of GIP in regulation of intestinal secretions?
Functions to decrease gastric motility and secretion but also has a modulatory effect on intestinal motility and secretion
104
What is the neural regulation of intestinal secretion?
Enteric nervous system
Parasympathetic Stimulation
Sympathetic Stimulation
105
How does the ENS act for neural regulation of intestinal secretions?
Independently of the central nervous system but influenced by it, it uses neurotransmitters such as Ach and VIP
106
What is the role of the parasympathetic stimulation in regulation of intestinal secretion?
Generally enhances digestive secretions, mainly involves the vagus nerve
107
What is the role of sympathetic stimulation in the regulation of intestinal secretion?
Generally inhibits secretions and motility
108
What are the local factors that affect the regulation of intestinal secretion?
Osmolarity
pH
Mechanical Distention
109
What is the result of high osmolarity on the regulation of intestinal secretion?
High osmolarity in the lumen can draw water into the lumen, dilutes luminal contents
110
What is the result of an acidic environment on the regulation of intestinal secretion?
An overly acidic environment in the duodenum can stimulate the secretion of bicarbonate to help neutralize the pH
111
What is the effect of mechanical distention of the regulation of intestinal secretions?
The presence of food or chyme in the intestine can stimulate secretion due to stretching of the intestinal wall
112
Where does most of the absorption take place?
In the small intestine
113
What is the major site of nutrient absorption in the small intestine?
Brush border, microvilli
114
In terms of volume which of the intestines absorbs more water?
The small intestine
115
How are nutrients absorbed in the small intestine?
They are trapped in folds of the intestinal wall and absorbed through the microvilli
116
What does each villus contain?
Blood vessels and a lymph vessel which transports nutrients
117
Which substances are absorbed in the duodenum and the jejunum?
Most minerals, including Ca, Fe, and Mg
118
Which minerals cannot be absorbed in the duodenum/jejunum area so they are absorbed in the small intestine instead?
Na, Cl and K
119
What makes the environment of the duodenum optimal for mineral absorption?
Higher pH due to the bicarbonate secretions from the pancreas
120
What gets absorbed in the jejunum and the upper ileum?
Carbohydrates and amino acids which enter the bloodstream through enterocytes
Water soluble vitamins
121
Which vitamins are water soluble?
Vitamin B and C
122
What is the jejunum specialized in absorbing?
Fat soluble vitamins
Micelles (lipids that are emulsified by bile acids)
123
What does the terminal ileum absorb?
Vitamin B12
Primary site for bile salt reabsorption
124
What is the importance of primary bile salts reabsoprtion?
Recycling bile acids for future fat digestion
125
What are the different mechanisms of absorption?
Passive diffusion
Facilitated diffusion (requires a carrier)
Active transport
Endocytosis
126
Where are water and salts absorbed?
In the large intestine
127
What are chylomicrons?
Large triglyceride-rich lipoproteins produced in enterocytes from dietary lipids
128
Where do the chylomicrons go?
The main function of transport is to the lumen of the liver. However, some end up going to adipocytes for storage or muscle cells for energy
129
Where are water-soluble nutrients absorbed into?
Circulatory system
GI tract --> Hepatic portal vein --> Liver
130
What are examples of water soluble nutrients?
Carbohydrates, amino acids, and water-soluble vitamins
131
Where are lipid soluble nutrients absorbed?
Lymphatic system
Lymph capillaries --> Lymphatic vessels --> Thoracic duct
132
What are examples of fat-soluble nutrients?
Fat-soluble vitamins, long chain fatty acids, proteins that are too large to be transported via capillaries
133
What is the function of the large intestine?
Absorbs water, electrolytes and some vitamins
134
How many liters of water does the large intestine absorb daily?
1 to 2 liters of water daily from the chyme
135
What does the water absorbed in the large intestine form?
Semi-solid faeces
136
What is the absorption method of water in the large intestine?
Osmosis, regulated by the electrolyte concentration in the intestinal lumen and blood
137
What electrolytes are absorbed in the large intestine?
Na+, Cl- and K+
138
How is Na+ absorbed? What facilitates it?
Actively absorbed in exchange for K+, facilitated by aldosterone
139
How is Cl- absorbed in the large intestine?
Passively absorbed, often following Na+ absorbption
140
What is the function of Na+ absorption in the large intestine?
Helps maintain body's electrolytes and fluid balance
141
How is K+ absorbed in the large intestine?
Secreted into the intestinal lumen in exchange for Na absorption
142
Which vitamins are absorbed in the large intestine?
Vitamin K and Biotin (Vitamin B7)
143
How is vitamin K synthesized?
Synthesized by gut microbiota in the colon
144
What is the purpose of vitamin K absorption?
Essential for blood clotting processes
145
Where is Biotin produced?
Produced by intestinal bacteria
146
What is bacterial fermentation?
The large intestine houses a diverse bacterial flora that ferments undigested carbohydrates, producing short-chain fatty acids
147
What is the byproduct of bacterial fermentation?
Gases
148
What are examples of the short-chain acids produced from bacterial fermentation?
Acetate
Propionate
Butyrate.
149
Where are short-chain fatty acids absorbed? What is their effect?
Absorbed by the colon and provide additional energy
150
Why does the large intestine produce mucus?
To facilitate the smooth passage of stool and protect the mucosal lining
151
What are the major and unique functions of the large intestine?
Absorption of water, electrolytes and produce Vitamin K and B7
152
What is the source of short-chain fatty acids?
Composition of dietary fibers and resistant starches, found in whole grain foods, fruits, vegetables, and legumes
153
What is the fermentation of short-chain fatty acids?
It happens in the colon, beneficial anaerobic bacterial breakdown of these undigested carbohydrates
154
Which is the most abundant SCFA produced?
Acetate
155
What are the roles of acetate?
Being a substrate for cholesterol synthesis
156
What are the roles of propionate?
Involved in gluconeogenesis and can inhibit cholesterol synthesis
157
What is the primary energy source for colonocytes?
Butyrate
158
What are the roles of butyrate?
Has anti-inflammatory properties and supports the health and integrity of the colonic mucosa
159
What are the benefits of SCFA?
Gut health
Metabolic health
Immune function
160
How do SCFA help with gut health?
Through anti-inflammatory effects, it promotes colonocyte health and may protect against colon cancer
161
How do SCFA help with metabolic health?
Influence metabolism by affecting appetite regulation, improving insulin sensitivity, modulating fat storage
162
What is the immune function of SCFA?
Reducing the risk of inflammatory disease
163
Where are SCFA absorbed? What happens to them?
Rapidly absorbed by colonocytes, once absorbed, it can be utilized locally or enter the systemic circulation to be used by other tissues or for other metabolic processes
164
What kind of diet can help promote production of beneficial SCFAs?
Fiber-rich, it also supports overall gut health
165
