Gastrointestinal Physiology Flashcards
Endocrine secretions of the intestine
GIP
CCK
Secretin
Gastrin
Glucagon-Like Peptide (GLP)
Then enteric nervous system, endocrine cells, paracrine cells and local tissue factors are examples of ___________ control of the GI tract.
Then enteric nervous system, endocrine cells, paracrine cells and local tissue factors are examples of Intrinisic control of the GI tract.
Factors that increase blood flow to the GI tract
NO
PSNS Stimulation
_________ acts on muscarinic receptors, inhibits Somatostatin and promotes histamine and gastrin.
AcH acts on muscarinic receptors, inhibits Somatostatin and promotes histamine and gastrin.
___________ of the GI tract spontaneously depolarizes and repolarizes
Visceral Smooth Muscle of the GI tract spontaneously depolarizes and repolarizes
GI: __________: increases the reabsorption of Na+ and increases the secretion of K+, is NOT vasoactive.
Aldosterone: increases the reabsorption of Na+ and increases the secretion of K+, is NOT vasoactive.
__________
Increases peptic cell secretion
Contraction of LES and pyloric spincter
Increase gastric motility and blood flow
Gastrin
_____________ are necessary for digestion.
Hydrolytic Enzymes are necessary for digestion.
_________ drugs block histamine receptors
-tidine drugs block histamine receptors
In dogs and cats, the pancreas produces ________, which is unlike many other species.
In dogs and cats, the pancreas produces GIF, which is unlike many other species.
__________ use water to break bonds
Hydrolytic Enzymes use water to break bonds
Peristalsis
Movement in the aborad direction
Perfusion of the GI tract is controlled by :
Autonomic Nervous System
Endocrine Secretion
Paracrine Secretion
Local Tissue Factors
HCO3 production is (increased/decreased) by prostaglandins
HCO3 production is (increased/decreased) by prostaglandins
Preganglionic neurons of the _________ nervous system origniate from the vagus or pelvic nerves to have effect on the GI tract.
Preganglionic neurons of the parasympathetic nervous system origniate from the vagus or pelvic nerves to have effect on the GI tract.
__________: increased secretion of HCO3 into the lumen and H into the plasma.
Acid Tide: increased secretion of HCO3 into the lumen and H into the plasma.
_____________ of the heart allow the action potential to travel the fastest due to the least resistance.
Perkinje Fibers of the heart allow the action potential to travel the fastest due to the least resistance.
Local tissue factors have a ___________ effect on the blood vessels of the Gi tract
Local tissue factors have a vasodilatory effect on the blood vessels of the Gi tract
__________ nervous system neurons originates from the craniosacral plexus.
Parasympathetic nervous system neurons originates from the craniosacral plexus.
________ is only secreated by the salivary glands and follicular cells of the thyroid glands.
Iodide is only secreated by the salivary glands and follicular cells of the thyroid glands.
__________ secretions of the intestine increase secretion by stimulating crypt cells and are vasodilatory
Paracrine secretions of the intestine increase secretion by stimulating crypt cells and are vasodilatory
_____________________
Histamine and Prostaglandin
Types of Intestinal secretions
Exocrine
Paracrine
Endocrine
Antiperistalsis is a prominant feature in what species
Equine
______________________
Feature at the pelvic flexure to allow for increased fermentation time
___________: paracrine secretion that increases GI motility.
Serotonin: paracrine secretion that increases GI motility.
Ruminants use salivary glands as
Ruminants use salivary glands as a source of ruminal and reticular fluid
_______________________
Essential to buffer acid produced by fermentation
GI cells throughout their lifetime move from ________ to ___________
GI cells throughout their lifetime move from crypt to villi
The __________ of the GI tract is largely reabsorptive, especially to Cl and Na.
The Large Intestine of the GI tract is largely reabsorptive, especially to Cl and Na.
Describe how protein is broken down for absorption
Protein broken down to oligopeptides by protease
Oligopeptides broken down to amino acids by brush border oligopeptidases
___________- blood leaving the stomach is markedly alkaline.
Alkaline Tide- blood leaving the stomach is markedly alkaline.
________ and _________ are transported from the pancreas for digestion together.
Amylase and Protease are transported from the pancreas for digestion together.
____________: Stimulates gastrin secretion and promotes closrue of the pyloric sphincter with CCK.
Gastrin: Stimulates gastrin secretion and promotes closrue of the pyloric sphincter with CCK.
________ and _______ are products of the parasympathetic nervous system that aid in the perfusion of the GI tract.
VIP and NO are products of the parasympathetic nervous system that aid in the perfusion of the GI tract.
Dogs and cats use salivary glands for __________.
Dogs and cats use salivary glands for evaporative cooling.
The composition of saliva is similar to plasma, with the exceptions of
Increased PO4 in ruminant saliva
Increased [I]
ACH bound to muscarinic receptors promotes the secretion of _______ from the epithelium.
ACH bound to muscarinic receptors promotes the secretion of NO from the epithelium.
_________ blocks all muscarinc receptors
Atropine blocks all muscarinc receptors
________ nervous system neurons originates from the thoracolumbar plexus
Sympathetic nervous system neurons originates from the thoracolumbar plexus
_______ control of the GI is achieved through the regulation of perfusion.
Indirect control of the GI is achieved through the regulation of perfusion.
_________: from the SNS vasoconstricts and decreases blood flow of the GI tract.
Norepinephrine: from the SNS vasoconstricts and decreases blood flow of the GI tract.
__________ cells of the GI tract are acid inhibiting by inhibiting gastrin.
D cells of the GI tract are acid inhibiting by inhibiting gastrin.
____________: stimulated by acidic luminal pH.
Stimulates bile and pancreatic secretion and crypt cell secretion
Inhibits gastric secretion, gastric motility and gastric emptying
Secretin: stimulated by acidic luminal pH.
Stimulates bile and pancreatic secretion and crypt cell secretion
Inhibits gastric secretion, gastric motility and gastric emptying
Antiperistalsis
Movement in the orad direction
___________ of the heart generates the action potential.
SA Node of the heart generates the action potential.
Peristalsis occurs in what part of the stomach
Antrum
The GI tract can receive up to ______% of cardiac output.
The GI tract can receive up to 30% of cardiac output.
Proton moves into the GI lumen by way of _________ in the Gastric Parietal Cells.
Proton moves into the GI lumen by way of H-K ATPase in the Gastric Parietal Cells.
________________
Increased pancreatic enzyme
Increased pancreatic cell death
Inflammation
Pancreatitis
Side effect of -prazole drugs
H+ is sequestered inside the cell which leads to increased pH in the lumen. Can lead to bacterial overgrowth
Example of plant beta-polymer carbohydrates
Cellulose
Water enters the lumen by osmosis, it follows _________ secretion.
Water enters the lumen by osmosis, it follows Cl- secretion.
Interstitial cells of the GI tract differ from cardiac pacemaker cells in that
Interstitial cells of the GI tract differ from cardiac pacemaker cells in that interstital cells dont depolarize all the way to threshold
____________
Produced by the glandular stomach
Stimulate release of Growth Hormone
Appetite promoting
Peaks right before a meal
Promote food intake by decreasing sensitivity to distention receptors
Ghrelin
Transporters on the Parietal Cells of the GI tract
H-K ATPase
HCO3-Cl Exchanger
Cl Channel
K Channel
Describe the negative feedback mechanism on D cells of the GI tract
Increased lumen [H+] stimulates D cells
Increased ACH due to the PSNS inhibits D cells
____________ reflex is initiated by gastric dilation and its effect is peristaltic and mas movement at the distal colon (entry of feces into the rectum)
Gastrocolic reflex is initiated by gastric dilation and its effect is peristaltic and mas movement at the distal colon (entry of feces into the rectum)
_________ nervous system acts as a pre-synaptic inhibitor of GI tract motility
Sympathetic nervous system acts as a pre-synaptic inhibitor of GI tract motility
The gastrointestinal tract has a protective function due to ____________.
The gastrointestinal tract has a protective function due to immunocytes.
The exocrine glands make tubular fluid alkaline by reabsorbing __________ and secreting _________.
The exocrine glands make tubular fluid alkaline by reabsorbing Cl- and secreting HCO3-.
Phases of Gastric Motility
Cephalic Phase
Gastric Phase
Intestinal Phase
____________ secretes the majority of hydrolytic enzymes.
Pancreas secretes the majority of hydrolytic enzymes.
Filtration and flow through the kidney is voluntary/involuntary.
Filtration and flow through the kidney is voluntary/involuntary.
___________
“Inhibitory”
@Stomach: inhibits histamine secreting cells
Somatostatin
_________ secretion: enters the lumen of the tubular gut at the mouth or small intestine- more alkaline
Secondary secretion: enters the lumen of the tubular gut at the mouth or small intestine- more alkaline
Regulation of GI function is largely under __________ control.
Regulation of GI function is largely under CNS control.
T/F: Carbohydrates, Protein and Lipids can be absorbed in the form ingested.
False
______________________
They must be digested in order to be absorbed
_____ cells of the GI tract are acid promoting.
ECL cells of the GI tract are acid promoting.
__________ functions to emulsify lipid. Separates lipid into small pieces to increase surface area and keeps the pieces from going back together.
Bile functions to emulsify lipid. Separates lipid into small pieces to increase surface area and keeps the pieces from going back together.
After _________ flow through the gastrointestinal tract becomes involuntary.
After swallowing flow through the gastrointestinal tract becomes involuntary.
Describe how carbohydrate is broken down for absorption
Starch/Glycogen broken down to Maltose (and other products) by amylase
Amylase products are broken down into transportable forms by brush border enzymes
VIP and AcH in the GI tract promote the production of ________.
VIP and AcH in the GI tract promote the production of NO.
Inhibitory motor neurons of the GI tract secrete ______, ______ and __________ to cause relaxation.
Inhibitory motor neurons of the GI tract secrete NO, VIP and ATP to cause relaxation.
Electrolytes that can always be found in the GI lumen
Cl, K, Na and Water
H-K ATPase only found in
Gastric Parietal Cells
Alpha Intercalated Cells
_________ drugs inhibit H-K ATPase transporters
-prazole drugs inhibit H-K ATPase transporters
CO2, H+ and K+ are examples of
Local Tissue Factors
Carbohydrates can be absorbed in ________ and __________ forms.
Carbohydrates can be absorbed in alpha-polymer and beta-polymer forms.
________ stimulates skeletal muscle to contract.
AcH stimulates skeletal muscle to contract.
___________ plays an important role in overall control of insulin relased by beta cells of the pancreas.
Gastric Inhibitory Peptide (GIP) plays an important role in overall control of insulin relased by beta cells of the pancreas.
There is a significant increase in luminal __________ ports in the colon.
There is a significant increase in luminal Na uniports ports in the colon.
_________ control mechanisms are initiated outside of the GI tract.
Extrinsic control mechanisms are initiated outside of the GI tract.