Digestion 2 Flashcards
The largest ‘gland’ of the body is the ______ weighing in at about __ pounds.
- Liver
2. 3 pounds
The liver is composed of lobules that contain what type of cells? What do these cells produce?
- Hepatocytes
2. Bile
What is the purpose of bile. How does it work?
Necessary for emulsification/digestion of fats
Increases surface area of fats
There are 8 functions of the LIVER. What are they?
- Bile production
- Storage of iron/copper
- Storage of glucose
- Synthesis/Storage/Release of Vitamins
- Synthesis of fibrinogen/prothrombin used in clotting
- Phagocytosis of foreign object in blood
- Detoxification of substances in blood
- Plasma protein synthesis
What 3 common proteins are synthesized in the liver?
- Albumin
- Fibrinogen
- Angiotensinogen
What are the characteristics of ‘Cirrhosis’. What may cause this disease?
Normal liver epithelium is replaced by connective tissue causing blockage of sinusoids
Alcohol/Malnutrition may cause cirrhosis
What are the characteristics of ‘Hepatitis’?
Inflammation of the liver caused by viruses, protozoa and bacteria.
There are two types of Hepatitis. What are they?
- Hepatitis Infectious (A)
2. Hepatitis Serum (B)
What are the characteristics of ‘Jaundice’? What causes this disease?
Yellowish coloration of the skin and mucous membranes.
Caused by excessive accumulation of free or conjugated ‘BILIRUBIN’.
What are some of the functions and characteristics of the gallbladder?
Sac-like organ attached to common bile duct that sits under the liver.
Stores/Concentrates and releases bile.
How much bile does the ‘liver’ secrete a day?
600-1000 bile ml/day
How much bile can the ‘gallbladder’ store? How concentrated is the bile stored here compared to that of the liver?
- Storage = 30-70 ml
2. Up to 20 times more concentrated than bile from liver
How is bile regulated? (There are 3 steps)
- Fat/Partially digested proteins in S.I. (small intestine) tract causes release of CCK (cholecystokinin)
- Rhythmical contraction of the gallbladder
- Peristaltic waves of duodenum relax sphincter of ampulla (*Vagal stimluation)
Where is ‘cholecystokinin’ (CCK) released from?
Intestinal mucosa
How are gallstones formed?
Precipitation of substances contained in bile (cholesterol/bilirubin)
What are the two major substances contained in bile?
Cholesterol
Bilirubin
There are 3 factors which cause cholesterol to become hyperconcentrated in the bile which causes gallstones. What are the 3 factors?
- Stasis of bile (too much absorption of water)
- High levels of cholesterol in blood
- Inflammation of the gallbladder
Gallstones occur in about __% of the population.
20%
There are 4 factors that cause gallstones to be more common in the people, what are the 4 factors?
- Obesity
- Middle-aged
- Diabetes
- Female
What will happen is gallstones move into the bile duct?
Block flow of bile into the small intestines
Bile pigments become present in high concentration in the liver/other body fluids and tissues.
Jaundice occurs
What is the major mixed gland (endocrine/exocrine) of the body?
Pancreas
What are some characteristics and functions of the pancreas
Attached to the duodenum
Endocrine function of insulin and glucagon secretion into blood.
Exocrine function of digestive enzymes into the S.I. in response to presence of chyme in upper portion of the S.I.
The pancreas secretes 4 digestive enzymes. What are they?
- Amylase
- Lipase
- Peptidase
Trypsin
Chymotrypsin
Carboxypeptidase - Bicarbonate
What is the function of ‘amylase’?
Hydrolyzes starch and glycogen into disaccharides
What is the function of ‘lipase’?
Converts fats into fatty acids and monoglycerols
What is the function of ‘peptidases/proteolytic enzymes’?
Trypsin/Chymotripsin/Carboxypeptidase
Convert proteins or partially digested proteins into amino acids
What is the functions of ‘bicarbonate’? (There are two of them)
Neutralizes acid in the stomach
Provides environment for pancreatic enzymes to function
What is ‘Acute Pancreatitis’?
Damaged pancreas that builds a pool of secretions in damaged areas
Trypsin inhibitor is overwhelmed and secretions WILL digest the entire pancreas in a few hours
In ‘Gastro-Intestinal Tract Regulation’, there are 2 controls that regulate gastric secretion. What are the 2 controls?
- Nervous Control
2. Hormonal Control
In ‘Nervous Control’ regulation of gastric secretion, there is one factor that regulates secretion. What is it and what three things does it cause to happen?
Increased parasympathetic activity (vagus nerve)
- Increased gastric juice secretion
- Increased contraction (Peristalsis/Segmentation)
- Increased release of gastrin (hormone)
Where is gastrin released?
From the ‘G cells’ (enteroendocrine cells) from the walls of the stomach
What are the 4 factors that will stimulate secretion of gastrin from the ‘Hormonal Control’ system in G.I. tract regulation?
- Food entering the stomach
- Partially digested proteins
- Alcohol/Caffeine
- Histamine/Calcium
Gastrin causes 2 bodily functions to increase. What are they?
- Increased gastric juice secretion
2. Increased peristalsis
What are the two hormones that help regulate pancreatic secretions?
- Secretin
2. CCK (Cholecystokinin)
What are some of the characteristics of the ‘Secretin’ hormone? (There are 5 of them)
- Secreted from ‘S’ cells when pH drops in duodenum
- Travels in blood to pancreas. Pancreas causes secretion of pancreatic juice rich in ‘BICARBONATE’
- Bicarbonate neutralizes the acid.
- This process prevents formation of ulcers in the S.I.
- Also increases contraction of the pyloric sphincter
What are some of the characteristics of the ‘Cholecystiokinin (CCK)’ hormone? (
- Released from ‘I’ cells in the duodenal/upper jejunal mucosa when proteins/fats/fatty acids enter the S.I.
- Stimulate secretion of pancreatic juice rich in ‘ENZYMES’ for digestion.
- Stimulates contraction of the gallbladder/release of bile to aid digestion of lipids
What are the effects of ‘Acetylcholine’ (ACh) on the regulation of pancreatic secretions? (There are 2 of them)
- Released from parasympathetic system
2. Stimulates pancreatic secretion
What is ‘anabolism’?
Construction of complex molecules from simple building blocks (Amino acids to Complex protein)
Biosynthesis of proteins
*Anabolic steroids
What is ‘catabolism’?
Breaking ‘down’ process
Glucose is broken down to yield energy and waste products.
What is the definition of ‘digestion’?
Consumed food is broken down into small pieces to be absorbed into the blood stream
There are 3 main types that food can be broken down into?
- Proteins (Amino Acids a.a.)
- Fats (Fatty Acids & Glycerol)
- Carbohydrates (Monosaccharides\Glucose)
True or False:
All three classes of nutrients (carbohydrates, lipids, and proteins) can be used to provide cellular energy and generally CAN be interconverted.
TRUE
They CAN be interconverted
What will happen is a person does not eat hardly any fat? How will their body create cellular energy?
The body will make fat from carboyhydrates and protein and use that to provide cellular energy
These 3 type of nutrients cannot be formed or interconverted, they must be ingested. What are they?
- Essential amino acids
- Vitamins
- Minerals
There are only 3 major sources of carbohydrates that exist in the normal diet. What are they?
- Sucrose (Cane Sugar)
- Lactose (Milk Sugar)
- Starches (Large Polysaccharides)
___________ are the body’s major source of energy.
Carbohydrates
When carbohydrates get low, what does the body use as secondary or supplementary fuel?
Fats and Proteins
Nervous tissue can only utilize what as an energy source.
Glucose
What is the process of taking a fat to the final product in the digestive system? What is the final product?
Fat w/ Bile = Fat Globules
Fat Globules w/ Lipase = Glycerol and fatty acids
When proteins are digested they form amino acids. How is this process performed?
Proteins -> Polypeptides -> Small polypeptides and amino acids -> Amino acids
Absorption of food materials from the gut into the body occurs via 2 methods of transport. What are the two methods?
- Active Transport
2. Diffusion
True or False
ALL electrolytes are easily absorbed and do not require active transport.
FALSE:
Some electrolytes REQUIRE Active Transport
What hormone will greatly increase the rate of transport of glucose into most cells?
Insulin
True or False
After transport into the cells, glucose can be used IMMEDIATELY for the release of energy to cells or be stored in the form of glycogen.
TRUE
Can be used immediately
Can be stored as glycogen
What is the process of making glycogen from glucose?
Glycogenesis
What is the process of breaking down glycogen to glucose?
Glycogenolysis
When the body breaks down one molecule of glucose, what does it turn into? (3 Things)
- Carbon Dioxide
- Water
- Energy (ATP)
What are the two main processes in making energy (ATP)?
- Glycolysis
2. Cell Respiration
Cell Respiration is broken down into 3 sub-processes. What are the 3 sub-processes?
- Pyruvate Decarboxylation
- Krebs Cycle
- Electron Transport Chain
What is ‘glycolosis’?
Splitting of glucose into 2 molecules of pyruvic acid.
How much ATP is formed from ‘glycolysis’?
2 ATP
If not enough oxygen is available, what happens to cell respiration?
Cannot go beyond glycolysis
True or False:
Under ‘anaerobic’ conditions, cell respiration can occur and more then 2 ATP’s are formed.
FALSE:
Under ‘anaerobic’ conditions, cell respiration CANNOT occur.
Only 2 ATP’s are then formed.
What is the ‘net result’ of the ‘Krebs Cycle’ for each molecule of glucose?
Release of 16 Hydrogen atoms
Production of only 2 ATP
What is the ‘net result’ of the ‘Electron Transport Chain’ for each molecule of glucose?
32 ATP
What is the total amount of ATP produced in Glucose Catabolism? (Glycolysis, Krebs Cycle, Electron Transport Chain)?
36 ATP
There is a __% efficiency of energy transferred and stored as ATP. The remaining __% is released as heat and not used for cellular function.
- 66% Efficiency of Energy
2. 34% Released as Heat (Unused)
What percentage of the calories in our diet are derived from fats?
40-45%
What is the average percentage of carbohydrates that are converted into fatty acids and stored for energy usage later?
20-50%
True or False
Proteins (amino acids) cannot be converted into acetyl CoA.
FALSE:
Proteins CAN be converted into Acetyl CoA
(*Only if needed)
How much saliva is each of the three salivary glands responsible for secreting?
Paratid: 20%
Submandibular: 60%
Sublingual: 20%
True or false: All three sets of salivary glands produce mucous.
FALSE! All three sets produce serous fluid enzyme, but on the submandibular and sublingual produce mucous.
Where are the parotid glands located?
In front of the ear between the skin and masseter muscle
Where are the submandibular glands located?
Midway along the inner side of the jaw
Where is the sublingual gland located?
Under the mucosa in the floor of the mouth
There is a sphincter on each end of the stomach. One is highly developed and the other is not. Which is not very well developed and thus doesn’t regulate effectively?
The lower esophageal sphincter (cardiac sphincter) is not well developed, whereas the pyloric sphincter is very highly developed.
What is a hiatal hernia?
the protrusion (herniation) of the upper part of the stomach through the diaphragm and into the thorax
What is the pH of gastric juice?
Urine?
Sweat?
Gastric Juice- 1.9-2.6
Urine- 5.7
Sweat- 4- 6.8
What is the pH of Saliva?
Breast milk?
Pancreatic juice?
Saliva- 6.4
Breast Milk- 7
Pancreatic Juice- 7.9
What takes place during pyruvate decarboxylation?
The two pyruvic acid molecules are converted into two molecules of acetyl coenyzme A
Protein in first chemically broken down in what?
STOMACH
Which of the following is absorbed in the stomach?
- Protein
- Fats
- Sugar
- Aspirin
- ASPIRIN
Mumps is what?
A viral disease of the parotid ‘salivary’ glands
What is the pH of ‘INTESTINAL JUICE’?
pH = 7.6
Which of the following is NOT released by the pancreas?
- Trypsin
- Amylase
- Pepsin
- Carboxypeptidase
- PEPSIN
Gastrin is released by the ___________ cells in the stomach.
G CELLS
Secretin is released by the _________ and acts on the _________.
- SMALL INTESTINE
2. PANCREAS
Glycogenolysis is what?
Breaking down GLYCOGEN to GLUCOSE.
The process of converting two pyruvic acid molecules into 2 molecules of acetyl CoA is known as what?
PYRUVATE DECARBOXYLATION
Which hormone is utilized when blood glucose levels DROP?
GLUCAGON