Term
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Definition
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Term
| Appetite determines what? |
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Definition
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Term
| Food intake is regulated by what? |
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Definition
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Term
| Long term regulation of food intake is primarily concerned with what? |
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Definition
| Maintenance of normal qualities of energy stores in the form of fat in the body |
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Term
Short term regulation of food intake is primarily concerned with what?
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Definition
| Preventing overeating at each meal |
|
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Term
| What 3 systems regulate food intake? |
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Definition
| CNS, Endocrine System, GI System |
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Term
| How is the lateral hypothalmic area involved in food intake regulation? |
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Definition
| Simulates food intake and storage of calories (hunger center) |
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Term
| How is the ventromedial nuclei of the hypothalmus involved in food intake regulation? |
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Definition
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Term
| What is the function of the Melanocortin Pathway? |
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Definition
| A hypothalmic pathway that increases metabolism and inhibits food intake |
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Term
| What is the function of the neuropeptide Y - mediated pathway? |
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Definition
| A hypothalmic pathway that stimulates food intake and decreases metabolism (hunger signals) |
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Term
Leptin has what clinical effect on appetite and metabolism?
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Definition
| Decreasd Appetite, increased Metabolism |
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Term
CCK has what clinical effects?
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Definition
| Decreased appetite, decreased gastric emptying |
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Term
PYY has what clinical effect on appetite and metabolism?
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Definition
| Decreased appetite, increased metabolism |
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Term
| Which part of the GI tract prevents pulmonary aspiration? |
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Definition
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Term
| Which part of the GI tract prevents gastric reflux? |
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Definition
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Term
| Which part of the GI tract is the major site of nutrient digestion and absorption and the site of synthesis of GI regulatory hormones? |
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Definition
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Term
| What are the four general processes in the GI tract? |
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Definition
| Motility, Secretion, Digestion, Absorption |
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Term
| What produces Cholecystokinin? |
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Definition
| I cells in the duodenum and jejunum and neurons in the ileum and colon |
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Term
| What produces gastric inhibitory peptide? |
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Definition
| K cells in duodenum and jejunum |
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Term
|
Definition
| G cells in the antrum of the stomach |
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|
Term
| What stimulates the release of Gastrin? |
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Definition
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Term
|
Definition
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Term
|
Definition
| M cells in duodenum and jejunum |
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Term
| What are the effects of Cholecystokinin? |
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Definition
| Pancreatic enzyme secretion, gallbladder contraction |
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|
Term
| What are the effects of Gastric Inhibitory Peptide? |
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Definition
| Decreased fluid absorption, insulin release, decreased gastric motility and emptying |
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|
Term
| What are the effects of Gastrin? |
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Definition
| Increased H+ secretion, increased Pepsinogen secretion |
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Term
| Whare the effects of Guanylin? |
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Definition
| Increased fluid absorption and increased smooth muscle contraction |
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|
Term
| What are the effects of Motilin? |
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Definition
| Increased GI motility and initiates the migrating motor complex |
|
|
Term
| What are the effects of Neurotensin? |
|
Definition
| Vasoactive stimulation of histamine release |
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|
Term
| What exhibits Extrinsic control of GI functions? |
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Definition
|
|
Term
| What exhibits Intrinsic control of GI functions? |
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Definition
|
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Term
| What is the role of the CNS in regulation of GI functions? |
|
Definition
| Appetite/Hunger, cephalic phase of digestion, voluntary muscles of the GI tract (mouth, upper 1/3 esophagus, pharynx, external anal sphincter), pain, defecation |
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Term
| What effects do Parasympathetic nerves generally have on the GI tract |
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Definition
| Excitatory effect (increased motility, secretion, blood flow) |
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Term
What effects do Sympathetic nerves generally have on the GI tract
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|
Definition
Inhibitory effect (Vasoconstriction, Decreased GI motility, Decreased secretion activity)
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|
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Term
| Which major neurotransmitter of the enteric NS is excitatory? |
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Definition
|
|
Term
| Which major neurotransmitter of the enteric NS is inhibitory? |
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Definition
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|
Term
| Which non-peptide neurotransmitters of the enteric NS are inhibitory? |
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Definition
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|
Term
| What are the peptide neurotransmitters of the enteric NS? |
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Definition
| Vasoactive Intestinal Peptide (VIP), Substance P |
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Term
| What do short reflexes in the GI control? |
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Definition
| Secretion, Peristalsis, Mixing Contraction |
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|
Term
| What controls short reflexes in the GI tract? |
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Definition
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|
Term
What do long reflexes in the GI control?
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Definition
| Pain and Defecation reflexes, Gastrocolic, Enterogastric, and Colonoileal reflexes, Gastric Motor and Secretory activity |
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|
Term
| What electrically connect smooth muscle cells? |
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Definition
|
|
Term
| Describe the function of Interstitial Cells of Cajal |
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Definition
| Pacemaker cells in the caudad stomach and the intestine, generating fluctuating membrane potential as slow waves |
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Term
| Describe Electrical Slow Waves (Basic Electrical Rhythm aka BER) |
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Definition
| Spontaneous cycles of deporalization and repolarization of GI smooth muscle |
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|
Term
| What determines the frequency of rhythmic contraction? |
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Definition
| Frequency of the BER (Basic Electrical Rhythm) |
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|
Term
| How does the frequency of the BER vary? |
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Definition
| By region (3min in the stomach, 12min in the duodenum) |
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Term
| What causes smooth muscle contraction? |
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Definition
| Spikes (action potentials) |
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Term
|
Definition
| Interstitial Cells of Cajal (ICC) |
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Term
| Where is there a complete lack of slow waves? |
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Definition
| Esophagus and proximal stomach |
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|
Term
| What influences slow waves? |
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Definition
| Body temp and metabolic activity |
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Term
| What causes slow wave depolarization and repolarization? |
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Definition
| NA+ influx and KA+ eflux respectively |
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Term
| What causes depolarization and repolarization leading to contraction in the GI? |
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Definition
| Ca 2+ influx and K+ efflux respectively |
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Term
| What phase are slow wave action potentials leading to GI contraction associated with? |
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Definition
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Term
| What is the force of contraction in the GI directly proportional to? |
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Definition
| Frequency of Action Potentials |
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Term
| What are depolarizing factors that stimulate GI smooth muscle contraction? |
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Definition
| Stretching of muscle, parasympathetic stimulation via Ach |
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Term
| What are Hyperpolarizing factors that inhibit GI smooth muscle contraction? |
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Definition
| Sympathetic stimulation (norepinephrine), Epinephrine |
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Term
| What is Basal Myogenic Tone? |
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Definition
| Tonic contraction of GI smooth muscle generated internally, NOT ASSOCIATED WITH BER, maintains continuous contraction |
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Term
| What characterizes tonic contraction of GI smooth muscle? |
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Definition
| Very low ATP consumption via latch mechanism |
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Term
| What increases the intensity of contraction in Basal Myogenic Tone |
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Definition
| Increased number of APs, increased Ca influx, partial depolarization |
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Term
| Where is the Ileocecal Spincter? |
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Definition
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Term
| Where is the Internal Anal Sphincter? |
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Definition
|
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Term
| Where is the External Anal Sphincter? |
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Definition
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Term
| Where is the Colorectal Sphincter? |
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Definition
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Term
| Describe the time spent in each segment of the GI tract |
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Definition
| Mouth = 8-10s, Stomach = 1-2hrs, Feces = up to 72hrs |
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Term
| Which patterns of muscle contractile activity are integrated within the Enteric NS? |
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Definition
| Segmentation (mixing) and Peristalsis (propulsion) |
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Term
| Focal contraction of the circular muscle layer describes what? |
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Definition
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|
Term
| Circular muscle contraction that spreads unidirectionally in the aborad direction describes what? |
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Definition
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|
Term
| Parasympathetic signals have what effect on motility? |
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Definition
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|
Term
| Sympathetic signals have what effect on motility? |
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Definition
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|
Term
| Myogenic regulation of GI motility controls what? |
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Definition
| Local control and contractile rhythm (BER) |
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Term
| What controls the muscles involved in chewing? |
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Definition
|
|
Term
| Describe the pharyngeal stage of deglutition |
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Definition
| 6 seconds, airway closed, respiration stopped, initiates esophageal peristalsis |
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Term
| Describe the esophageal stage of deglutition |
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Definition
| 8-10 seconds, primary and secondary peristalsis, relxation of lower esophageal sphincter and the stomach |
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Term
| Aborad propulsion of food bolus into the oropharynx by the tongue describes what? |
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Definition
| Voluntary stage of deglutition |
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Term
| Involuntary transportation of food from the posterior mouth and pharynx into the esophagus describes what? |
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Definition
| Pharyngeal stage of deglutition |
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Term
| What initiates the pharyngeal stage of swollowing? |
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Definition
| Epithelial receptor in the pharynx |
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Term
| Involuntary propulsion of ingested foodstuff through the esophagus into the stomach describes what? |
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Definition
| Esophageal stage of deglutition |
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Term
| A propulsive aborad contractile wave within the esophagus that is initiated through pharyngeal receptor contact describes what? |
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Definition
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|
Term
| What controls primary peristalsis? |
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Definition
| The Vagus Nerves along with the esophageal myenteric plexus |
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Term
| Propulsive aborad contractile waves within the esophagus that is initiated through pharyngeal receptor contact describes what? |
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Definition
|
|
Term
| What controls primary peristalsis? |
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Definition
| Vagus nerves in connection with the esophageal myenteric plexus |
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Term
| What sweeps the esophagus of residual food particles? |
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Definition
|
|
Term
| What controls secondary peristalsis? |
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Definition
| Myenteric and extrinsic NS |
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Term
| When does the lower esophageal sphincter relax? |
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Definition
| Shortly before the peristaltic wave arrives (receptive relaxation) |
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Term
| Loss of the lower esophageal sphincter relaxation and peristalsis of the esophagus leading to functional obstruction and progressive esophageal dilation describes what? |
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Definition
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|
Term
| Abnormalities in amplitude of swallowing contraction where >20% of swallows result in simultaneous contraction describes what? |
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Definition
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|
Term
| Peristaltic contractions of increased amplitude and/or duration describes what? |
|
Definition
| Hypertensive peristalsis (nutcracker esophagus) |
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|
Term
| What defines a hypertensive lower esophageal sphincter? |
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Definition
| Increased resting pressure |
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|
Term
| What defines hypotensive a lower esophageal sphincter? |
|
Definition
| Decreased resting pressure |
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Term
| Decreased amplitude of perstaltic or nonperistaltic contractions in distal esophagus describes what? |
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Definition
| Hypotensive peristaltic contractions (ineffective) |
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Term
| Gastric acid reflux, weak secondary peristalsis, and low lower esophageal sphincter tone describes what? |
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Definition
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Term
| Degeneration of the postganglionic inhibitory neurons in the myenteric plexus causing abnormalities in peristalsis and in the tone of the lower esophageal sphincter, food obstruction, and progressive esophageal dilation describes what? |
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Definition
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Term
| What is the vagovagal reflex? |
|
Definition
| A stretch reflex the reduces the tone in the muscular wall of the body of the stomach, initiated by food |
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Term
| Which part of the stomach mixes and homogenizes food? |
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Definition
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Term
| What controls mixing waves in the stomach |
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Definition
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|
Term
| What controls the amount of food that leaves the stomach? |
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Definition
| Muscle contractions of the antrum |
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Term
| What limits the size of particles empyting from the stomach into the duodenum? |
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Definition
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|
Term
| What kind of neural stimulation increases gastric motor activity |
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Definition
| Parasympathetic via the vagal nerves |
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Term
| What kind of neural stimulation decreases gastric motor activity? |
|
Definition
| Sympathetic (celiac ganglion) |
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|
Term
| What hormone increases contraction of the caudad stomach, increasing motility? |
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Definition
|
|
Term
| What hormones suppress stomach motility? |
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Definition
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|
Term
| Emptying of isotonic, non-caloric fluids in the stomach is proportional to what? |
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Definition
| Volume or distension of the stomach |
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Term
| Which kinds of fluid empty more slowly from the stomach? |
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Definition
| Hypertonic and hypotonic fluids empty slower than isotonic fluids |
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Term
| What effect does pH have on the emptying of the stomach? |
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Definition
| Lower pH = slower emptying |
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|
Term
| What is the result of slower than normal gastric emptying? |
|
Definition
| Interrupts flow of nutrients, overstimulation of gastric acid, poor digestion and absorption |
|
|
Term
| What is the result of faster than normal gastric emptying? |
|
Definition
| Overwhelmed digestive and absorptive capacity of the small intestine, acidic chyme not fully buffered, poor digestion and absorption |
|
|
Term
| What stimulates intestinal motility? |
|
Definition
| Parasympathetic stimulation, CCK, Gastrin |
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Term
| What do parasympathetic innervation, CCK, and Gastrin cause in order to stimulate small intestinal motility? |
|
Definition
| Spike Potentials leading to contraction |
|
|
Term
| What hormones inhibit small intestine motility? |
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Definition
| Epinepherine, VIP, Secretin, Glucagon (as well as ATP and NO) |
|
|
Term
| What hormones stimulate small intestine motility? |
|
Definition
| Gastrin, CCK, Insulin, motilin, Serotonin |
|
|
Term
| What causes intestinal receptors to trigger the enterogastric reflex? |
|
Definition
| Hydrogen ions, distension, changes in osmolarity |
|
|
Term
| What is the effect of the enterogastric reflex? |
|
Definition
| Decreased gastric motility and slowed rate of gastric emptying, protecting the intestines from excessive acidity |
|
|
Term
| What activates the ileocecal reflex |
|
Definition
|
|
Term
| What is the effect of the ileocecal reflex? |
|
Definition
| Increases motility of the ileum and relaxes the ileocecal sphincter, allows chyme to pass to the cecum, protects against reflux of colonic contents |
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|
Term
| What activates the gastroileal reflex? |
|
Definition
|
|
Term
| What is the result of the gastroileal reflex? |
|
Definition
| Increases ileal motility and movement through the ileocecal sphincter |
|
|
Term
| What part of the CNS controls vomiting? |
|
Definition
|
|
Term
| What is the most common motility action in the large intestines? |
|
Definition
| Haustrations (segmenting contractions) |
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|
Term
| What is the purpose of Haustrations (segmenting contractions in the Large Intestines) |
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Definition
| Mixes contents with little net propulsion |
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|
Term
| What kind of neural control inhibits motility in the large intestines? |
|
Definition
| Sympathetic stimulation and enteric stimulation mediated by VIP via NO |
|
|
Term
| What part of the large intestine is voluntarily controlled? |
|
Definition
|
|
Term
| What is the purpose of the gastrocolic reflex? |
|
Definition
| Stimulates gastric emptying which reflexly stimulates mass colonic movement |
|
|
Term
| What is the effect of the duodenalcolic reflex? |
|
Definition
| Duodenal distension increases stimulation of colonic mass movement, responsible for defecation sensation |
|
|
Term
| What are the boundaries of the rectum? |
|
Definition
| Internal and external anal sphincters |
|
|
Term
| What initiates defecation? |
|
Definition
|
|
Term
| What increases the urge to defecate by intensifying the peristaltic waves through the distal colon, rectum, and anus, allowing for the relaxation of the internal anal sphincter? |
|
Definition
|
|
Term
| What nerve controls the external anal sphincter? |
|
Definition
|
|
Term
| What is rectal accomodation? |
|
Definition
| Constriction of the external anal sphincter delays defecation, causing the internal anal sphincter to regain tonic control until a new mass movement begins a new defecation reflex cycle |
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|
Term
| How long does it take for transit through the colon? |
|
Definition
|
|
Term
| The migrating motor complex is associated with what body state? |
|
Definition
|
|
Term
| What initiates the migrating motor complex? |
|
Definition
|
|
Term
| What is the purpose of the migrating motor complex? |
|
Definition
| Prevents bacterial overgrowth in the gut by sweeping the gastric acid to the ileum |
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|
Term
| A lack of spikes and contractions describes which phase of the migrating motor complex? |
|
Definition
|
|
Term
A irregular spikes and contractions describes which phase of the migrating motor complex?
|
|
Definition
|
|
Term
A bursts of spikes and contractions describes which phase of the migrating motor complex?
|
|
Definition
|
|
Term
| What is the source of hunger pangs, stomach growls? |
|
Definition
| Migrating Motor Complex in the stomach |
|
|
Term
| What hormones initiates the migrating motor complex in the small intestines? |
|
Definition
| Motilin in response to neural signals |
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