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58 Cards in this Set
- Front
- Back
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Can you describe some physical characteristics of the liver? |
- Largest gland - 3 Lbs - Four Lobes |
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What is the main digestive function of the liver? |
Bile secretion |
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What are the 3 parts of the port hepatis? |
- Hepatic portal vein - Hepatic artery - Hepatic duct |
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Can you describe the microscopic anatomy of the liver? |
Hepatic lobule - central vein - hepatocytes - bile salts from cholesterol, etc. - hepatic sinusoids - bile caniculi Hepatic triad - Artery, vein, and bile duct |
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Is the pancreas an exocrine gland or an endocrine gland? |
It's both! |
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What kind of cells produce pancreatic juice? |
These cells are called acing cells. |
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What do the acing cells secrete? |
- zymogen grnuoles - enzymes |
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What do the gland cells of the pancreatic duct secrete? |
- Sodium bicarbonate |
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What does the sodium bicarbonate do? |
It buffers the acidic chyme entering the duodenum. |
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What is the neural effect of bile and pancreatic juice regulation? |
- Paraympathetic (vagal) stimulation - Sympathetic Inhibition |
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Can you describe hormonal bile and pancreatic juice regulation? |
- Gallbladder contraction and pancreatic secretion - Cholycytokinin - (CCK) - Gastrin - Hepatic and pancreatic bicarbonate secretion - Secretin |
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Where does most chemical digestion and nutrient absorption occur? |
The small intestine |
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What are the 3 parts of the small intestine in order? |
1st - Duodenum - 1st 25 cm or 10 inches 2nd - Jejunum - next 2.5 m or 8 ft. 3rd - Illeum - last 3.6 m or 12 ft. |
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Which of the 3 parts is the most important of the small intestine? |
The 1st - duodenum |
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What is the purpose of the circular folds within the small intestine? |
Increase surface area along with the mucosa and submucosa to help force chyme to spiral through. |
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What are villi?
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- Absorptive cells (enterocytes)
- brush border of microvilli - brush border enzymes - goblet cells - mucous - lacteal cells - fat - intestinal crypts - panted cells |
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What is secreted from duodenal glands?
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Bicarbonate - rich mucous
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What are the functions of intestinal motility?
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- Mix with intestinal juice, bile, pancreatic juice
- Contact digestionand nutrient absorption - Move residue to Li |
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What is segmentation?
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Mixing/contact digestion
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What are some of the workings of peristalsis?
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- Migrating motor complex
- Movement through SI |
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Can you describe what breaks down into what during digestion?
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Carbohydrates
- complex CHO to sugars Proteins - proteins to AA's Lipids - fats to FAs and monoglycerides Nucleic Acids - RNAs and DNAs into nucleotide monomers |
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Can you describe the absorption process of digestion?
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Absoprtion
- completed when chyme reaches ileum - ileum reclaims bile salts - end of ileum - remains some water, indigestible material, bacteria - passed into large intestine |
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How do carbohydrates digest in the mouth?
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Salivary amylase
- starch to oligosacharides |
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How do carbohydrates digest in the stomach?
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They don't unless the salivary amylase is protected from the stomach acid by hiding in the bolus.
- Churning, mixing - inactivation of salivary amylase |
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How do carbohydrates digest in the small intestine?
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Pancreatic amylase
- oligosacs to smaller oligosacs and disacs Dextrinase and glucomylase - brush border enzymes, smaller oligosacs and disacs Maltase, sucrase, lactase - brush border enzymes, disacs to sacs |
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How is glucose absorbed into cells?
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- Sodium-dependent glucose transporter (SGLT)
- Secondary active transport coupled to sodium |
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How is galactose absorbed into cells?
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- Sodium-dependent glucose transporter (SGLT)
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How is Fructose absorbed into cells?
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- Via facilitated diffusion
- gets converted into glucose |
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Where are the carbohydrates transported to after absorption?
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The liver
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How is protein digested in the stomach?
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Pepsin
- peptide bonds - Tryosine and phenlylananine - polypeptides and amino acids left |
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How is protein digested in the small intestine throguh pancreatic enzymes?
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- trypsin and chymotrypsin
- taken apart one amino acid at a time |
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What are 3 brush border enzymes involved in protein digestion in the small intestine?
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- carboxypeptides (pancreatic secretion)
- aminopeptides - dipeptides |
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Can you describe some of the major characteristics of protein absorption?
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- similar to monosacharride absorption as in they also have different sodium-dependent contras porters
- Dipeptides and tripeptides are also absorbed by being hydrolyzed within cytoplasm into AA - AA oud of absorptive cells through facilitated diffusion to blood capillaries of villus. |
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What is emulsification?
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During lipid digestion, lecithin and bile salts coat fat droplets
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What is the role of pancreatic lipase in lipid digestion?
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- TRG into FFA and monoglycerides
Micelle formed - coating of bile acids |
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What do micelles do?
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Pass through microvilli of the brush border
- fats diffusion into absorptive cell - transported to golgi complex - chylomicrons formed |
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What do chylomicrons do since they are too large to enter the capillaries?
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- move into lacteals
- taken through larger lymph vessels |
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How do some FFAs enter the capillary blood?
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Chylomicrons hydrolized to FFa and glycerol
- lipoprotein lipase Taken to liver - lipoproteins made |
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Where breaks up nucleotides?
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Pancreatic nucleases
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What brush border enzymes play a role in nucleic digestion?
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nucleosidases
phosphatases |
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What do nucleic active transport mechanisms transport and to where?
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They transport pentose sugars, nitrogenous bases, and phosphate ions into the blood
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What are the fat soluble vitamins and what does that mean?
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A, D, E and K or fat soluble and so they can absorbed with other lipids
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What are the water soluble vitamins and how do they accomplish absorption?
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B and C and through simple diffusion
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How does vitamin B12 undergo absorption?
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- Absorbed bound to intrinsic factor
- Vitamin B12 intrinsic factor complex - binds to specific mucosal receptor sites in the ileum and is absorbed by endocytosis |
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Where are most minerals absorbed?
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Along the length of the small intestine
- Sodium contransported (sugars and AA) - Chloride actively transported - in ilium with bicarbonate ions - potassium absorbed by simple diffusion - Iron and calcium - based on body's needs |
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How much water does the Gi tract receive per day?
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- About 9 L per day
- Mostly derived from Gi tract secretions - About 8 L absorbed by small intestine and .8 absorbed by large intestine - |
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How does water absorption occur?
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- Moves across intestinal mucosa via osmosis
- Concentration gradient - established by active transport of solutes - water uptake is coupled to solute uptake - affects rate of absorption |
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From what chemical are bile salts synthesized?
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Review Question
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What is the first factor of optimal digestive activity in the intestine as chyme is concerned?
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Review Question
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What is the trigger for excitatory phase of intestinal gastric secretion?
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Review Question
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What is the tenia coli?
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-Strips of smooth muscle
- haustra - pouches
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What does Bacterial flora contribute to?
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- intestinal gas
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What causes motility of the large intestine?
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- Haustra
- Mass movements |
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What is the advantage of the smooth muscle fibers in the intestinal villi?
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Review question
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What are the differences between peristalsis, churning, and segmental affects?
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Review Question
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What is release by the intestines because of the presence of chyme?
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Review Question
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What influences local regulation of pancreatic secretions?
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Review Question
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Where are most of the chemicals for intestinal digestion produced?
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Review Question
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