Digestion And Absorption Flashcards
HCL
Begins digestion of protein in stomach
Gastrin
Hormone released in stomach to stimulate gastric secretions and motility
CCK
Released from duodenum when fat enter
Causes contraction of gallbladder releasing bile
Stimulates pancreas
Secretin
Hormone released from duodenum
Stimulates flow of pancreatic juice bicarbonate to neutralize acidic chyme and water
Inhibits gastric acid secretion
GLP1 and GIP
Hormone released from the intestine in presence of glucose and fat
Stimulates insulin synthesis and release
Foods that slow gastric emptying
High fat and complex cho (esp soluble fibers)
These foods empty at about the same rate from the stomach
Carbohydrate and protein
Gastric emptying usually takes
2-6 hrs
Most digestion is completed by
The middle of the jejunum
Vitamins synthesized by bacteria in the large intestine and used by GI mucosal cells
Vitamin k
B12
Thiamine
Riboflavin
Pepsin
Enzyme in stomach that begins digestion of protein
Branched chain amino acids
Valine, leucine, isoleucine
Exercise releases what amino acid from muscle to be converted to glucose?
Alanine
Nitrogen balance equation (measures body equilibrium)
(protein intake g / 6.26) - [(urinary urea nitrogen +4) / urinary urea nitrogen]
Net protein utilization equation(determines quality of protein in foods)
(N intake - N output) / N intake
Essential amino acids
TV TILL PMH
threonine, valine, tryptophan, isoleucine, leucine, lycine, phenylalanine, methionine, histadine
Anabolism of protein: hormones
Pituitary growth hormone, thyroid, insulin, testosterone
Protein catabolism: hormonal control
Glucocorticoids(adrenal steroids) - stimulate gluconeogenesis
End products of fat metabolism
Monoglycerides
Dilglycerides
Glycerol
Fatty acids
What fat products are absorbed directly into portal blood?
Glycerol
Short chained fatty acids
What fat products are combined with Bile salts to form micelles?
Mono- and diglycerides
Long chained fatty acids
These are then bound to protein to form lipoproteins (chylomicron), penetrate intestinal mucosa, travel through lymph into the thoracic duct into the blood
What is found in all cells and is important to cell structure? Some is absorbed with bile salts. Excreted by liver as bile
Cholesterol
Enzyme that absorbed most cholesterol
Cholesterol esterase
2 Metabolic activities of fat:
Lypogenesis - energy storage; adipose tissue and liver
Liver should not store fat - choline produce lipoproteins to transfer fatty acids out of the liver
Lipogensis requires what substance from the pentose shunt?
NADPH
Oxidation of fatty acids yields
Acetyl CoA - enters Krebs
Hormones that cause lypolysis
Glucagon, growth hormone
Glucocorticoids, thyroxine, epinephrine, ACTH - increase rate of fat mobilization
Hormone that causes lipogenesis
Insulin
Uphill pumping from lower to higher concentration, across membrane against an energy gradient
Needs energy from ATP
Glucose, amino acids, Na,K,Mg,Ca,Fe
Active transport/ Sodium pump
Higher to lower concentration
Intestine to blood and lymph
Some water and electrolytes use this method
Simple diffusion
Carrier facilitated
Water soluble nutrients
Higher to lower concentration
Passive diffusion
AIDS absorption of A
Bile salts
Pancreatic lipase
Fat
AIDS absorption of D
Bile salts
Acidity of chyme
Accompanies Ca, P absorption
Aids E,K absorption
Bile salts, fat
Aids absorption of thiamin
Acid
Aids absorption of riboflavin
Phosphorous
Aids absorption of B12
Ileum Stomach secretions (HCL, Intrinsic factor)
Aids calcium absorption
Acid
Vitamins D
Lactose
Aids iron absorption
HCL
Calcium (binds oxalates)
Central regulation of food intake
Hypothalamus gland
