Carbohydrates Flashcards
What is digestion?
Chewing (mechanical) and secreting acids and enzymes from stomach and bile, pancreas, small intestine (chemical)
What is absorption?
Movement of the smallest particles of food across the small intestine lining that is 1-cell thick, goes into blood/lymph circulation
What two types of ileocecal valves are there?
Papillary and labial type
What is the endocrine portion of the pancreas called and what two hormones does it secrete?
Islets of Langerhans secrete insulin and glucagon
What do the duct cells of the pancreas secrete?
Aqueous NaHCO3 solution
What do the acinar cells of the pancreas secrete?
Digestive enzymes
What does small intestine digestion that’s stimulated by the neuroendrocrine system begin with?
Pancreas secretions: bicarb + water to neutralize stomach acid, enzymes to digest food
What are the three phases of pancreatic actions?
Cephalic, gastric, intestinal phase
What’s involved in the cephalic phase of pancreatic actions?
Smell, taste, chewing, swallowing causes vagus nerve to stimulate pancreatic secretions
What’s the gastric phase of pancreatic actions?
Gastric distension stimulates vagus nerve to stimulate pancreatic secretions
What’s the intestinal phase of pancreatic actions?
Digestive products trigger release of hormones that control secretion of CCK and secretin
What cells release CCK? What does it do?
I cells of pancreas release CCK; stimulates enzyme and bile secretion for digestion
What cells release secretin? What does it do?
S cells of pancreas; stimulates water and bicarb secretion
What autonomic NS inhibits pancreatic secretions CCK and secretin?
Sympathetic NS (opposite of what controls pancreatic secretions)
What are the 2 phases of small intestine CHO and protein digestion?
Pancreatic enzymes breaks big into small
Brush border enzymes break small into single units
What is the range of # glucose units in an oligosaccharide?
3-10
What are the 6 major small intestine carbohydrases?
Amylase (pancreas), isomaltase, maltase, sucrase, lactase, trehalase
What are the carbohydrate transporters?
SGLT1=glucose, galactose
GLUT5=fructose
GLUT2=glucose, fructose, galactose
What happens to CHOs when it is malabsorbed by SI?
Get fermented by bacteria, creating gas
CHOs draw water osmotically in the intestine
What is the transport system, cotransported ion, type of transport, and membrane location of oligopeptides?
PEPT1
H+
Secondary active transport
Apical membrane (facing lumen)
What are two tight junction functions?
GATE function: regulate passage of micro and macro molecules through paracellular space
FENCE function: keep microbiota and large substances out for our protection
What physical action opens tight junctions?
Actin contraction
What can intestinal permeability in leaky gut cause?
Systemic symptoms, that is a main cause of rxns every time you eat
What are the 7 causes of increased intestinal permeability?
Diet Medications Infections: bacterial overgrowth Stress Hormones Neurologic Metabolic
