30 Questions
Which type of smooth muscle cells in the GIT are responsible for generating slow wave potentials?
Autorhythmic cells
What is the primary function of autorhythmic cells in the GIT?
To generate slow wave potentials
What is the effect of an increase in the frequency of spike potentials on the amplitude of GIT smooth muscle contraction?
It increases the amplitude of contraction
What is the effect of acetylcholine on the GIT motility?
It increases the frequency of generation of spike potentials
What is the role of Ca2+ channels in the slow wave potentials?
They cause the depolarizing phase of the slow wave
What is the effect of the ENS, ANS, and hormones on the amplitude of slow wave potentials?
They influence the amplitude of slow wave potentials
What is the characteristic of smooth muscle cells that allows them to contract in unison?
They are interconnected by gap junctions
What is the primary function of the splanchnic circulation?
To absorb nutrients from the gut
Which type of transport requires energy and involves transporters?
Primary active transport
What is the main site of absorption of major nutrients?
Small intestine
What is the movement of products of digestion from the lumen of the gut into the bloodstream or lymph?
Absorption
What type of smooth muscle cells produce the opposite effects of adrenaline and noradrenaline?
Contractile smooth muscle cells
What is the primary function of the motor neurons in the myenteric plexus?
Control of GIT motility
What is the estimated number of neurons in the enteric nervous system?
100 million
What is the primary function of the interneurons in the enteric nervous system?
Interconnection of neurons in the myenteric and submucosal plexuses
Where is the submucosal plexus, also known as the plexus of Meissner, located?
Within the submucosa
Which of the following is NOT a component of the enteric nervous system?
Cerebellum
What is the name of the plexus located between the longitudinal and circular smooth muscle layers of the muscularis externa?
Myenteric plexus
Where are the preganglionic sympathetic neurons that supply the GIT localized?
Thoracic and upper lumbar regions of the spinal cord
Which ganglion innervates the small intestine and the proximal part of the large intestine?
Superior mesenteric ganglion
What is the effect of stimulation of sympathetic nerves on the GIT?
Reduced motility and secretion of GIT
Which of the following is an example of a GIT reflex?
Response to chemical or mechanical stimulation of receptors in the GIT wall by food
Where do the postganglionic sympathetic fibers synapse in the GIT?
Myenteric plexus and submucosal plexus
Which of the following emotions may slow digestion?
Anger
What is the primary function of secretin in the gastrointestinal tract?
To stimulate the secretion of bicarbonates by pancreatic cells
Which of the following hormones is produced by I cells in the duodenum and jejunum?
Cholecystokinin
What is the primary function of histamine in the gastrointestinal tract?
To stimulate gastric acid secretion
Which of the following is a characteristic of paracrine agents in the gastrointestinal tract?
They are secreted by endocrine cells and act locally, without entering the systemic circulation
What is the primary function of somatostatin in the gastrointestinal tract?
To inhibit the secretion of gastrointestinal hormones and gastric acid secretion
What is the primary function of glucose-dependent insulinotropic peptide (GIP) in the gastrointestinal tract?
To inhibit gastric acid secretion and stimulate insulin secretion
This quiz covers the types of smooth muscle cells in the Gastrointestinal Tract (GIT), including autorhythmic cells and contractile cells. It also explores the location and function of these cells, including their role in motility and pacemaking.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
