PNB 2265 Exam 3 || 100% Error-free Answers.
Integrated meal response correct answers path of food from mouth to rectum
Integrated meal response phases correct answers cephalic
gastric
intestinal
colonic
Two parts of GI tract correct answers alimentary canal
accessory organs
Alimentary canal correct answers mouth
esophagus
stomach
small intestines
large intestines
rectum
Accessory organs of GI trac correct answers salivary glands
liver
pancreas
gallbladder
Peritoneum correct answers serous membrane that surrounds GI system that is different from
others bc it folds in on itself and btwn the folds are fat deposits
-made of parietal and visceral with peritoneal fluid between
Parietal peritoneum correct answers layer of serous membrane that lines the walls of the
abdominal cavity
Visceral peritoneum correct answers layer of serous membrane that covers the surface of organs
Order of tissue layers in GI tract (wall to lumen) correct answers serosa
muscularis
submucosa
mucosa
Serosa correct answers outer layer of tube that is connective tissue wrapper that holds things
together, protects them, and is site of attachment
Muscularis externa correct answers smooth muscle layer that has two layers, one longitudinal
outer layer and one circular inner layer with a myenteric plexis layer btwn
Muscularis externa layers (lumen to outer) correct answers circular layer
myenteric plexis
,Longitudinal layer
Myenteric plexis correct answers nerve tissue layer btwn the layers of the muscularis externa that
controls smooth muscle contraction and is under involuntary control by parasympathetic
stimulation
Longitudinal layer muscularis externa correct answers outer layer that gives you contractions that
will make the tube shorter or longer (controls length)
Circular layer muscularis externa correct answers inner layer that controls radius of the tube
Submucosa correct answers loose connective tissue that binds things together. Has large blood
vessels, large lymphatic vessels (galt), and nerves
Galt correct answers submucosa (gut) associated lymphatic tissue that has a lot of immune cells
since this is a point of entry for pathogens
Mucosa layers correct answers muscularis mucosae
lamino propria
epithelium layer
Muscularis mucosae correct answers mucosa layer that is the muscle part that shapes the surface
of the mucosal layer
Lamina propria correct answers connective tissue mucosal layer with tiny vessels (capillaries)
and small lymphatic vessels
Epithelium layer (mucosa) correct answers mucosa layer closest to lumen that has specializations
depending on where in the GI tract
-has enterocytes, enteroendocrine cells, and mucin-producing cells
Submucosal plexus correct answers nerves in the submucosa layer
Enterodendocrine cells correct answers secretory cells in epithelia of mucosa
Enterocytes correct answers cells that do absorption in epithelia of mucosa
Mucin-producing cells correct answers mucous producing cells in epithelia of mucosa
Peristalsis correct answers motility of GI tract that produces forward movment
-contraction of smooth muscle behind bolus to create high pressure behind and low pressure in
front
-found in esophagus, stomach, weak in small intestines, infrequently in large intestine
Segmentation correct answers Coordinating contractions in front and behind to create mixing
-proximal and distal contractions
, -faster frequency behind to still slightly push things forward
-primarily in small intestines
Phasic contractions correct answers quick contractions that produce movement (peristalsis and
segmentation)
Tonic contractions correct answers smooth muscles contracts and stays contracted to prevent
backflow
-is in sphincters
Smooth muscle contractions correct answers can contract more than other muscles due to
diagonal filaments and doesn't have to worry about refractory period
Smooth muscle contraction mechanism correct answers Uses MLCK to phosphoryalte myosin
chain and speed up ATP hydrolysis and promote contraction
-doesnt have tropomyosin or myosin head
Myosin Light Chain Kinase (MLCK) correct answers enzyme that when active can
phosphorylate myosin chain and speed up ATP hydrolysis in smooth muscle to promote
contraction
-anything that increases its activity promotes contraction
MLCK regulation correct answers -Ca activates it and promotes contraction
-cAMP inhibits it and causes relaxation
Myosin light chain phosphatase (MLCP) correct answers removes a phosphate from myosin
chain and is inhibitory to smooth muscle contration
Phosphodiesterase correct answers breaks down cAMP
Which membrane does secretion in GI tract correct answers apical membrane, closest to lumen
Which membrane does absorption in GI tract correct answers basal membrane
Secretion of bicarbonate ions correct answers in duct cells there is CO2 and H2O which enzyme
carbonic anhydrase will use to make H2CO3 which dissociates to H+ and HCO3-. H+ ion comes
out basal surface in exchange for Na (using gradient) through Na/H+ exchanger. Na/K pump on
basal surface is then used to fix the gradient. HCO3- will move through apical surface in
exchange for Cl- through Cl=HCO3- exchanger. Cl- then moved back across apical membrane
by CFTR channel to fix gradient
Chemical digestion correct answers breakdown of macromolecules to smaller units by secreted
enzymes
-occurs in esophagus, stomach, small intestine
Absorption correct answers passage of nutrients from the lumen into the tissues
Integrated meal response correct answers path of food from mouth to rectum
Integrated meal response phases correct answers cephalic
gastric
intestinal
colonic
Two parts of GI tract correct answers alimentary canal
accessory organs
Alimentary canal correct answers mouth
esophagus
stomach
small intestines
large intestines
rectum
Accessory organs of GI trac correct answers salivary glands
liver
pancreas
gallbladder
Peritoneum correct answers serous membrane that surrounds GI system that is different from
others bc it folds in on itself and btwn the folds are fat deposits
-made of parietal and visceral with peritoneal fluid between
Parietal peritoneum correct answers layer of serous membrane that lines the walls of the
abdominal cavity
Visceral peritoneum correct answers layer of serous membrane that covers the surface of organs
Order of tissue layers in GI tract (wall to lumen) correct answers serosa
muscularis
submucosa
mucosa
Serosa correct answers outer layer of tube that is connective tissue wrapper that holds things
together, protects them, and is site of attachment
Muscularis externa correct answers smooth muscle layer that has two layers, one longitudinal
outer layer and one circular inner layer with a myenteric plexis layer btwn
Muscularis externa layers (lumen to outer) correct answers circular layer
myenteric plexis
,Longitudinal layer
Myenteric plexis correct answers nerve tissue layer btwn the layers of the muscularis externa that
controls smooth muscle contraction and is under involuntary control by parasympathetic
stimulation
Longitudinal layer muscularis externa correct answers outer layer that gives you contractions that
will make the tube shorter or longer (controls length)
Circular layer muscularis externa correct answers inner layer that controls radius of the tube
Submucosa correct answers loose connective tissue that binds things together. Has large blood
vessels, large lymphatic vessels (galt), and nerves
Galt correct answers submucosa (gut) associated lymphatic tissue that has a lot of immune cells
since this is a point of entry for pathogens
Mucosa layers correct answers muscularis mucosae
lamino propria
epithelium layer
Muscularis mucosae correct answers mucosa layer that is the muscle part that shapes the surface
of the mucosal layer
Lamina propria correct answers connective tissue mucosal layer with tiny vessels (capillaries)
and small lymphatic vessels
Epithelium layer (mucosa) correct answers mucosa layer closest to lumen that has specializations
depending on where in the GI tract
-has enterocytes, enteroendocrine cells, and mucin-producing cells
Submucosal plexus correct answers nerves in the submucosa layer
Enterodendocrine cells correct answers secretory cells in epithelia of mucosa
Enterocytes correct answers cells that do absorption in epithelia of mucosa
Mucin-producing cells correct answers mucous producing cells in epithelia of mucosa
Peristalsis correct answers motility of GI tract that produces forward movment
-contraction of smooth muscle behind bolus to create high pressure behind and low pressure in
front
-found in esophagus, stomach, weak in small intestines, infrequently in large intestine
Segmentation correct answers Coordinating contractions in front and behind to create mixing
-proximal and distal contractions
, -faster frequency behind to still slightly push things forward
-primarily in small intestines
Phasic contractions correct answers quick contractions that produce movement (peristalsis and
segmentation)
Tonic contractions correct answers smooth muscles contracts and stays contracted to prevent
backflow
-is in sphincters
Smooth muscle contractions correct answers can contract more than other muscles due to
diagonal filaments and doesn't have to worry about refractory period
Smooth muscle contraction mechanism correct answers Uses MLCK to phosphoryalte myosin
chain and speed up ATP hydrolysis and promote contraction
-doesnt have tropomyosin or myosin head
Myosin Light Chain Kinase (MLCK) correct answers enzyme that when active can
phosphorylate myosin chain and speed up ATP hydrolysis in smooth muscle to promote
contraction
-anything that increases its activity promotes contraction
MLCK regulation correct answers -Ca activates it and promotes contraction
-cAMP inhibits it and causes relaxation
Myosin light chain phosphatase (MLCP) correct answers removes a phosphate from myosin
chain and is inhibitory to smooth muscle contration
Phosphodiesterase correct answers breaks down cAMP
Which membrane does secretion in GI tract correct answers apical membrane, closest to lumen
Which membrane does absorption in GI tract correct answers basal membrane
Secretion of bicarbonate ions correct answers in duct cells there is CO2 and H2O which enzyme
carbonic anhydrase will use to make H2CO3 which dissociates to H+ and HCO3-. H+ ion comes
out basal surface in exchange for Na (using gradient) through Na/H+ exchanger. Na/K pump on
basal surface is then used to fix the gradient. HCO3- will move through apical surface in
exchange for Cl- through Cl=HCO3- exchanger. Cl- then moved back across apical membrane
by CFTR channel to fix gradient
Chemical digestion correct answers breakdown of macromolecules to smaller units by secreted
enzymes
-occurs in esophagus, stomach, small intestine
Absorption correct answers passage of nutrients from the lumen into the tissues
