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