GI Motility Flashcards
The nerve is responsible for the parasympathetic innervation to the upper gastrointestinal tract, up to part of the transverse colon.
Vagus nerve
Postganglionic sympathetic fibers of the gastrointestinal tract synapse on ganglia on the plexuses, or directly innervate smooth muscle, endocrine or secretory cell
Myenteric and Submucosal
The (intrinsic/extrinsic) component of the autonomic nervous system of the gastrointestinal tract is composed of the sympathetic and the parasympathetic division.
Extrinsic
The nerve is responsible for the parasympathetic innervation to the lower gastrointestinal tract, from part of the transverse colon to the end.
Pelvic Nerve
Postganglionic neurons of the parasympathetic nervous system of the gastrointestinal tract can be either cholinergic or .
Peptidergic
The gastrointestinal tract is served by four sympathetic ganglia: celiac, superior mesenteric, inferior mesenteric, and .
Sympathetic Ganglia (GIT)
- Celiac
- Superior Mesenteric
- Inferior Mesenteric
- Hypogastic
The reflexes occurring in the gastrointestinal tract are termed reflexes when they involve the central nervous system centers.
Long
Since the vagus nerve is a mixed nerve, carrying both efferent and afferent fibers, it can trigger reflexes known as reflexes.
Vagovagal Reflexes
The reflexes occurring in the gastrointestinal tract are termed reflexes when they are mediated entirely by the enteric nervous system.
Short reflexes
The intrinsic or enteric nervous system (can/can not) direct the functions of the gastrointestinal tract in the absence of the extrinsic nervous system.
CAN
The (intrinsic/extrinsic) component of the autonomic nervous system of the gastrointestinal tract is called the enteric nervous system.
Intrinsic
Peptidergic neurons of the parasympathetic nervous system of the gastrointestinal tract release mediators such as and vasoactive intestinal peptide.
Substance P
VIP
The part of the autonomic nervous system contained by the submucosal and myenteric plexuses of the gastrointestinal system is called nervous system
Enteric Nervous System
The (primary/secondary) peristaltic wave in the esophagus begins at the site of distension to clear all food.
Secondary
The (primary/secondary) peristaltic wave in the esophagus is coordinated by the swallowing reflex.
Primary
During rest, the pressure at the lower esophageal sphincter is (higher/lower) than the pressure in the esophagus.
Higher
The function of the (upper/lower) esophageal sphincter is to prevent air from entering the esophagus
Upper
When standing or sitting, the primary peristaltic contraction in the esophagus is aided by .
Gravity
Before the esophageal peristaltic wave reaches the end of the esophagus, the sphincter relaxes reflexively to let food into the stomach.
Gastroesophageal sphincter
The (primary/secondary) peristaltic wave in the esophagus is coordinated by the enteric nervous system.
Secondary
Intraesophageal pressure is (lower/higher) than abdominal pressure due to the intrathoracic location of the esophagus.
LOWER
Intraesophageal pressure is (equal/unequal) to thoracic pressure.
EQUAL
The opening of the lower esophageal sphincter is mediated by the neurotransmitter , which is released by the vagus nerve.
VIP
The function of the (upper/lower) esophageal sphincter is to prevent acidic chyme from entering the esophagus.
Lower
The vasoactive intestinal peptide produces (relaxation/contraction) in the smooth muscle of the lower esophageal sphincter.
Relaxation
May occur if the loweresophageal sphincter does not relax during swallowing and food accumulats in the esophagus
Achalasia
The contractile rhythm of the stomach’s peristaltic waves is set by the enteric cells.
Pacemaker (Interstitial cells of Cajal)
Contractions in the caudad region of the stomach finish mixing the chyme and help propel it into the .
Small Intestine
Intrinsic factor is required to absorb vitamin in the ileum.
Vitamin B12
Gastrin stimulates parietal cells to secrete hydrogen ions (directly/indirectly) by causing the release of histamine from enterochromaffin-like cells.
Indirectly
The vagus nerve innervates the G cells of the stomach by releasing the neurotransmitter peptide.
Gstrin Releasing Peptide
Because the wave of contraction in the stomach closes the , much of the chyme that was destined for the duodenum is propelled back to the body of the stomach for further mixing.
Pylorus
The orad region of the stomach has a (thinner/thicker) muscle wall than the caudad region of the stomach.
Thinner
The antrum of the stomach contains glands that contain G cells and mucous cells.
PYLORIC glands
A high concentration of hydrogen ions in the stomach (inhibits/stimulates) gastrin secretion.
Inhibits
The muscle layer unique to the stomach is the inner (longitudinal/circular/oblique) layer.
Inner Oblique
The stomach receives (extrinsic/intrinsic) innervation through the myenteric and submucosal plexuses.
Intrinsic
The myenteric plexus of the stomach receives (parasympathetic/sympathetic) innervating fibers from the vagus nerve.
Parasympathetic
The muscular stomach wall has an (outer/inner) longitudinal layer.
Outer longitudinal
Isotonic contents empty from the stomach more (quickly/slowly) than hypotonic or hypertonic contents.
Quickly
The hydrochloric acid secreted by the parietal cells acidifies stomach contents so that inactive pepsinogen can be converted to active .
Pepsin
relaxation is when the orad region of the stomach relaxes due to the relaxation of the lower esophageal sphincter.
Receptive
The thickness of the stomach muscle lining (increases/decreases) as it becomes more distal from the gastroesophageal sphincter.
Increases
Receptive relaxation is mediated by vagus nerves acting on enteric nerves that release serotonin and .
NO
Chief cells and mucous cells in the stomach secrete the inactive precursor .
Pepsinogen
The body of the stomach contains chief cells within oxyntic glands which secrete to digest proteins.
Pepsinogen
Somatostatin inhibits hydrochloric acid secretion from parietal cells indirectly by inhibiting the release of and histamine.
Gastrin
Sympathetic stimulation (increases/decreases) the frequency of action potentials and the force of contraction in the stomach.
Decreases
The major (inhibitory/stimulatory) mechanism for hydrochloric acid secretion by parietal cells is through somatostatin.
Inhibitory
Acetylcholine (stimulates/inhibits) gastric parietal cells directly by binding to muscarinic receptors.
Stimulates
Acetylcholine stimulates gastric parietal cells indirectly by stimulating cells to release histamine.
Enterochromaffin like cells
The stomach receives (extrinsic/intrinsic) innervation through the autonomic nervous system.
Extrinsic
Alcohol and caffeine (stimulate/inhibit) gastric hydrochloric acid secretion.
Stimulate
Neural and hormonal input to the stomach (does/does not) influence the frequency of slow waves.
does NOT
There are three anatomic divisions of the stomach: the fundus, body, and .
fundus
body
antrum
Distension of the stomach wall activates -secreting cells to initiate more vigorous mixing.
Gatsrin secreting cells
The presence of fat in the stomach (increases/decreases) gastric emptying time.
Increases
The stimuli for hydrochloric acid secretion by the parietal cells in the phase include tasting, smelling, and chewing.
Cephalic phase
Gastric motility is (increased/decreased) when the enteric nervous system in the duodenum detects a low pH so that there is adequate time for neutralization.
Decreased
Amino acids and small peptides directly stimulate cells in the antrum of the stomach to release gastrin into circulation.
G cells
Somatostatin is secreted by cells to bind directly to parietal cells which causes a decrease in hydrochloric acid secretion.
D cells
The hydrogen ion that is secreted into the stomach lumen comes from the dissociation of acid in parietal cells.
Carbonic acid
The body of the stomach contains parietal cells within oxyntic glands which secrete hydrochloric acid and factor.
Intrinsic Factor
Hydrogen ions are secreted out of parietal cells into the lumen of the stomach through a (secondary/primary) active process.
Primary
The mucous neck cells within the pyloric glands of the stomach secrete mucus and to neutralize the acidic stomach contents.
Bicarbonate
The process of in the stomach forces chyme in the pylorus to be recycled back to the body of the stomach for more mixing.
Retropulsion
The stimuli for HCL secretion during the ______ phase include distention of the stomach and presnce of protein products
Gastric phase
Gastrin secreted by the G cells in the antrum of the stomach binds to cholecystokinin B receptors on cells to stimulate hydrogen ion secretion.
Parietal
The muscular stomach wall has an (outer/inner) longitudinal layer.
OUTER
The absorbed into the bloodstream is responsible for the alkaline tide in gastric venous blood after a meal.
Bicarbonate
Pepsinogen is only secreted when the hydrogen ion concentration is (high/low) enough that it can be converted to pepsin.
HIGH
The G cells within pyloric glands of the stomach secrete gastrin into the (duct/circulation) .
Circulation
The stomach can hold large amounts of food without drastically increasing internal pressure due to the plasticity afforded by the mechanism of gastric .
Accomodation
Gastrin secreted into the bloodstream reaches parietal cells by a(n) (endocrine/local diffusion) mechanism.
Endocrine
Liquids empty from the stomach more (quickly/slowly) than solids.
Quickly
A vagovagal reflex that is inititiated by distention of the stomach and abolished by vagotomy
Recetptive Relaxation
Participates in the receptive relaxatio by increasing distensibilty of the orad and stomach
CCK
This occur at 90 minutes intervals and clear the stomach of residual food
Migrating Myoelectric Complex
mediated by MOTILIN