GI System Flashcards
Which hormone will inhibit gastric secretions and motility?
a.Cholecystokinin.
b.Histamine.
c.Serotonin.
d.Gastrin.
a.Cholecystokinin.
Digestive enzymes are produced by which salivary cells?
a.Myoepithelial and serous cells.
b.Ductal and serous cells.
c.Myoepithelial cells
d.Serous cells.
e.Ductal cells.
f.Mucous and serous cells.
d.Serous cells.
What option is TRUE of salvia?
a.It is a hypertonic solution.
b.Secreted from two salivary glands.
c.Has proteases within it to start chemical digestion.
d.Parasympathetic nervous system is the predominant stimulation for its secretion.
d.Parasympathetic nervous system is the predominant stimulation for its secretion.
All options are true regarding the function of the stomach, except?
a.Absorption of proteins.
b.Food storage.
c.Chemical digestion.
d.Mechanical digestion.
a.Absorption of proteins.
Loss of mucous cell function can lead to damage of the epithelial layer of the stomach’s mucosa.
True
What hormone will stimulate gastric function?
a.Somatostatin.
b.Gastrin.
c.Cholecystokinin.
d.Secretin.
b.Gastrin.
All the options are true regarding gastric regulation, except?
a.The gastric phase leads to the majority of HCl secretion.
b.The enterogastric reflex stimulates the release of secretin and cholecystokinin.
c.The cephalic phase will stimulate HCl production via the CN IV Trigeminal Nerve.
d.The intestinal phase ultimately decreases gastric function.
c.The cephalic phase will stimulate HCl production via the CN IV Trigeminal Nerve.
Function of the bicarbonate - hydrogen ion ATPase pump is vital for proper production of HCl.
False
What cell of the stomach mucosa produces intrinsic factor?
a.Chief cells.
b.Mucous cells.
c.Neuroendocrine cells
d.Parietal cells.
d.Parietal cells.
All of the options are true regarding the mucosa layer of the GI tract, except?
a.The lamina propria allows for the majority of absorption.
b.Goblet cells are interspersed among the epithelial cells.
c.The enteroendocrine cells secrete various hormones that influence GI regulation.
d.Contains three layers.
a.The lamina propria allows for the majority of absorption.
What statement is FALSE regarding bile?
a.Mostly composed of water.
b.All of the options are true.
c.Bilirubin is reabsorbed and re-used by the liver.
d.Bile salts are reabsorbed and re-used by the liver.
c.Bilirubin is reabsorbed and re-used by the liver.
Why is the absorption of nutrients in the small intestine dependent upon cholecystokinin?
a.It stimulates the parietal cells allowing for mechanical digestion to occur.
b.It stimulates the motility and peristalsis within the small intestine.
c.It stimulates pancreas and gallbladder function.
d.None of the options are accurate.
c.It stimulates pancreas and gallbladder function.
What statement is TRUE regarding the small intestine?
a.The intestinal crypts assist with lipid absorption.
b.All of the options are false.
c.The brush border of the lamina propria has digestive enzymes.
d.For glucose to be absorbed into the enterocytes, it requires calcium.
b.All of the options are false.
All of the options are true regarding the small intestine, except?
a.Micelles are absorbed by enterocytes.
b.Water soluble vitamins are dependent upon bile salts for absorption.
c.Micelle formation is dependent upon bile.
d.Fat soluble vitamins are packaged into chylomicrons for absorption.
b.Water soluble vitamins are dependent upon bile salts for absorption.
SLGT1 cotransporter requires energy for glucose to be absorbed into the enterocyte’s apical side.
False
All of the options are needed for the absorption of lipids, except?
a.Gallbladder function.
b.Pancreatic function.
c.Gastrin function.
d.All of the options are needed of lipid absorption.
e.Lymphatic system function.
c.Gastrin function.
What option is TRUE regarding the small intestine?
a.Calcium absorption requires lipids for proper absorption.
b.Cholecystokinin released by the gallbladder will stimulate the pancreas to secrete digestive enzymes.
c.Digestive enzymes are released from the pancreas and are found on the brush border of the enterocytes.
d.Gastrin stimulates small intestine motility.
c.Digestive enzymes are released from the pancreas and are found on the brush border of the enterocytes.
This type of cell assists with the protection against pathogens in the small intestine?
a.Enteroendocrine cells.
b.Paneth cells.
c.Enterocytes.
d.Goblet cells.
b.Paneth cells.
If there was damage to the lamina proper of the small intestine, what option would be accurate?
a.Absorption of chylomicrons would be impaired.
b.Small intestine motility would be impaired.
c.Absorption of carbohydrates would be impaired.
d.None of the answers are accurate.
a.Absorption of chylomicrons would be impaired.
All of the options are needed for the absorption of carbohydrates, except?
a.All of the options are necessary for carbohydrate absorption.
b.Sodium-potassium ATPase pump within the enterocyte
c.Gallbladder function.
d.Pancreatic function.
c.Gallbladder function.
Layers of the GI Tract
-Serosa
-Muscularis Externa
-Submucosa
-Mucosa
Serosa Layer (Content/Function)
-Connective Tissue
-Holds the GI tract in place
Muscularis Externa (Content/Function)
-2 layers of muscle
-digestion (mechanical/chemical) and motility of food
Submucosa (Content/Function)
-Nerves, Blood Vessels, Lymphatic
-Has submucosal glands that release digestive secretions
Mucosa (3 Layers)
-Epithelial
-Lamina Propria
-Muscularis Mucosa
Contents/Functions of Lamina Propria
-Goblet Cells: Mucus
-Enteroendocrine: Hormones
-MALT: Immunity
What is saliva composed of?
IgA, H2O, Electrolytes, mucus (majority), lysosome, digestive enzymes (amylase, lipase)
Functions of saliva
-Forms bolus
-Cleaning/hydrates mouth
-Inhibits bacterial growth
-Digestions of starch and lipids
Types of gastric epithelial mucosal cells & what they secrete
-Goblet Cells: Mucus
-Enteroendocrine: Hormones
-Parietal Cells: HCL and intrinsic factor
-Chief Cells: Pepsinogen
-Stem Cells: Regenerate cells
Influence of different neuroendocrine cells on gastric function
-Serotonin: + (Enterochromaffin Cells)
-Gastrin: + (G Cells)
-Somatostain: - (Delta Cells)
-Histamine: + (Enterochromaffin-Like Cells)
Phases of Gastric Regulation
-Cephalic
-Gastric
-Intestinal
The Cephalic phase of gastric regulation controls _______% of all HCl secretion
30-40
What stimuli affect the Cephalic phase of gastric regulation?
Smelling, tasting, chewing, swallowing, thought of food
Cephalic: Mechanisms of HCl secretion
-Vagus Nerve Stimulation @ Enteric NS (secretes HCl)
-Vagus nerve stimulation of G-Cells->Gastrin->Parietal cells->HCl
The gastric phase of gastric regulation accounts for ____% of total HCL secretion in response to a meal
60
Gastric: Mechanisms for HCL secretion
- Stretching of the stomach: Vagus Stimulation->Parietal (Direct)/Gastrin->Patietal (Indirect)
- Protein Ingestion: G cells->Gastrin->Increased HCl and pepsinogen
- Release of Histamine from ECL cells (via gastrin)
The intestinal phase of gastric regulation accounts for ____ % of HCl production
10
In the intestinal phase, the _______ determines the rate of gastric emptying
Duodenum
Chyme is initially ______ but as more chyme enters it becomes ______
Stimulatory; Inhibitory
As more chyme enters and becomes inhibitory this reflex is triggered?
Enterogastric reflex
What does the Enterogastric reflex do?
-Sends - signals to: enteric NS & medulla (-PS/+S)
-+ duodenal neuroendocrine cells to secrete: Secretin and CCK
Secretin functions
-Responds to low pH levels by increasing bicarbonate
-This increases pH and H+ ions
Functions of CCK
-Pancreas +: Release of digestive enzymes
-Gallbladder +: Contraction
- gastric secretion/motility/emptying (-)
Pathway of bilirubin metabolism
RBC->Spleen->Albumin->Bilirubin-Liver->Bile->Small intestine->Urobillogen->4 Pathways
Functions of bile salts
-Emulsify lipids
-Form micelles
Enterohepatic circulation
Movement of bile acid salt molecules from the liver to the small intestine and back to the liver
Possible pathways of urobillogen
-Excretion of feces (80%)
-Urine Excretion (2%)
-Enterohepatic circulation (18%)
Portions of the enteric nervous system are found in the mucosa and submucosa.
False
What type of salivary gland cells are responsible for creating the hypotonic state of saliva?
a.Acinar cells.
b.Myoepithelial cells.
c.Serous cells.
d.Ductal cells.
d.Ductal cells.
This neuroendocrine hormone is a primary stimulator of gallbladder contraction.
a.Gastrin.
b.Somatostatin.
c.Secretin.
d.Cholecystokinin.
e.Histamine.
f.Histamine.
d.Cholecystokinin.
If there was a deficiency or impairment of this cell, it could lead an anemic state.
a.G-cell.
b.Parietal cell.
c.Chief cell.
d.Serous cell.
b.Parietal cell.
What statement is TRUE regarding the stomach?
a.The chief cells secrete pepsin, an enzyme that chemical digests proteins.
b.The stomach has two layers of smooth muscle in the muscularis externa layer.
c.The gastric pits only contain neuroendocrine cells.
d.None of the options are TRUE (all of the options are false).
d.None of the options are TRUE (all of the options are false).
All of the following neuroendocrine hormones stimulate gastrointestinal motility, except ______?
a.Gastrin.
b.Somatostatin.
c.Histamine.
d.Serotonin.
b.Somatostatin.
All of the statements are true regarding the mouth’s role in digestion, except ______?
a.Protein chemical digestion starts within the mouth.
b.Mastication is a primary role of the mouth within the digestion system.
c.There are three sets of salivary glands.
d.Saliva is a hypotonic solution that can contain antibodies.
a.Protein chemical digestion starts within the mouth.
The esophagus is composed of stratified squamous epithelium and a mixture of skeletal and smooth muscle.
True
All of the following options are mechanisms associated with the protection of the mucosa’s epithelial layer in the stomach, except _____?
a.Cell replacement by the stem cells.
b.Secretion of intrinsic factor.
c.Tight cellular junctions.
d.Mucous coat.
b.Secretion of intrinsic factor.
All of the options are true regarding the lamina propria, except ______?
a.It assists with contraction process of the mucosa.
b.It provides immune support to the gastrointestinal tract.
c.Contains the neuroendocrine cells that secrete hormones.
d.Contains blood and lymphatic vessels.
c.Contains the neuroendocrine cells that secrete hormones.
All of the options are true regarding gastric regulation, except _____?
a.The majority of HCl secretion occurs during the gastric phase.
b.The enterogastric reflex stimulates the parasympathetic nervous system innervation to the stomach.
c.During the cephalic phase, the majority of HCl secretion is initially stimulated by vagus nerve.
d.The enterogastric reflex occurs within the intestinal phase.
b.The enterogastric reflex stimulates the parasympathetic nervous system innervation to the stomach.
What are the two main neuroendocrine hormones that stimulate HCl secretion?
a.Histamine and gastrin.
b.Gastrin and serotonin.
c.Histamine and serotonin.
d.Somatostatin and histamine.
a.Histamine and gastrin.
All of the options are true regarding the gastrointestinal tract, except _____?
a.The mucosal layer has a layer of smooth muscle within it.
b.The submucosa contains blood vessels, nerves, and lymphatic vessels.
c.The epithelial layer of the mucosa changes depending on the region in the GI tract.
d.The enteric nervous system will only stimulate motility of the gastrointestinal tract.
d.The enteric nervous system will only stimulate motility of the gastrointestinal tract.
One mucin’s main role is to help ensure absorption of vitamin B12 occurs.
False; Intrinsic Factor
What option is TRUE regarding innervation of the gastrointestinal tract?
a.The parasympathetic nervous system inhibits secretions of the gastrointestinal tract.
b.The enteric nervous system depends on input from the autonomic nervous system to function.
c.The sympathetic nervous system will stimulate muscle contractions of the gastrointestinal tract.
d.The submucosal plexus regulates gastrointestinal tract secretions.
d.The submucosal plexus regulates gastrointestinal tract secretions.
All of the following enteroendocrine hormones will have stimulatory effect on gastric function, except ______?:
a.Somatotrophin.
b.Serotonin.
c.Gastrin.
d.Histamine.
a.Somatotrophin.
What option is true regarding lipid absorption?
a.Absorbed lipids by the enterocytes are repackaged in the endoplasmic reticulum.
b.The lymphatic system absorbs chylomicrons from the enterocytes.
c.Micelles are absorbed by lacteals.
d.Most of the bile salts are excreted out in the feces.
b.The lymphatic system absorbs chylomicrons from the enterocytes.
All of the options are true regarding the small intestine, except ______?
a.The parasympathetic system stimulates the small intestine secretions and motility.
b.Peristaltic contractions assist with mixing the chyme with the brush border.
c.The brush border of the mucosa will contain digestive enzymes.
d.The gallbladder and pancreas secrete digestive enzymes to assist with chemical digestion.
e.The villi contain the enterocytes.
d.The gallbladder and pancreas secrete digestive enzymes to assist with chemical digestion.
The production and release of the aqueous portion of the pancreatic juice is stimulated by secretin and cholecystokinin.
False
Glucose absorption is dependent on all of the following, except ______?
a.Sodium-potassium ATPase pump.
b.Sodium.
c.ATP.
d.SGLT1 cotransporter.
e.Glucose absorption is dependent on all of the options
e.Glucose absorption is dependent on all of the options
All of the following options are mechanisms for HCl secretion in the gastric phase, except ______?
a.Vagus nerve stimulation.
b.Stretching of the stomach.
c.Gastrin stimulating enterochromaffin-like cells to secrete histamine.
d.Protein ingestion.
a.Vagus nerve stimulation.
The Paneth cells found in the villi section of the epithelial mucosa will secrete substances to assist with pathogen protection.
False
The formation of the hastra is due to the peristaltic contractions.
False
All of the following options are true regarding histamine’s effect on the gastrointestinal tract, except ______?
a.Stimulates pepsinogen secretion.
b.Stimulates the HCl secretion.
c.Secreted from the enterochromaffin cells.
d.Stimulates gastric motility
a.Stimulates pepsinogen secretion.
All of the following options are true regarding hemoglobin metabolism, except ______?
a.Conjugated bilirubin is converted to urobilinogen by the liver.
b.A portion of urobilinogen will be reabsorbed into the enterohepatic circulation.
c.Unconjugated bilirubin travels to the liver attached to albumin.
d.The majority of urobilinogen is excreted out in the feces as stercobilin.
a.Conjugated bilirubin is converted to urobilinogen by the liver.
All of the following are functions of the large intestine, except ______?
a.Absorb remaining electrolytes.
b.Absorb vitamins produced by the gut flora.
c.Absorb remaining water.
d.Store fecal matter.
e.Produce bacteria for gut flora.
e.Produce bacteria for gut flora.
All of the options are true regarding the gallbladder, except ______?
a.The liver conjugates bilirubin to be secreted in the bile.
b.Cholecystokinin is the major hormone that stimulates secretion of bile.
c.Majority of the organic component of bile is bile pigments.
d.A function of bile is to create micelles.
c.Majority of the organic component of bile is bile pigments.
A chronic blockage of bile secretion could result in:
a.The possibility of the development of jaundice.
b.Inability to secrete waste products.
c.The possibility of the development of osteoporosis.
d.Impaired lipid absorption.
e.All of the options are true
e.All of the options are true
All of the following options are true of secretin, except ______?
a.Stimulates the pancreas to release digestive enzymes
b.Secretion is stimulated by a lower pH in the duodenum.
c.Suppresses gastric motility.
d.Suppresses gastric secretion.
a.Stimulates the pancreas to release digestive enzymes
All of the following options are true of cholecystokinin, except ______?
a.Stimulates the pancreas to release digestive enzymes.
b.Stimulates the gallbladder to contract.
c.Stimulates bile production.
d.Decreases HCl secretion in the stomach.
c.Stimulates bile production.
Sections of the small intestine & function
Duodenum: First 10 inches (chyme regulation)
Jejunum: 40% of small intestine (digestion/absorption)
Ileum: Last 60% of small intestine (peyer’s patches)
Anatomical structures assisting with increased surface area
-Circular folds
-Villi extensions
-Microvilli
What types of cells are contained in the epithelial portion
Goblet cells, Enterocytes, Enteroendocrine cells
______ compose majority of cells within the villi structure of epithelial cells and form the brush border
Enterocytes
Intestinal Crypts that are contained within epithelial cells constrain 4 types of cells including:
- Enterocytes/Goblet cells (upper half)
- Stem cells (lower half)
- Paneth cells (bottom-pathogen protection)
- Enteroendocrine cells (Secrete hormones/regulate digestion)
Motility in the small intestine has three goals
- Mix chyme with intestinal and pancreatic juice
- Churn chyme so it comes in contact with the brush border (to allow for enzyme absorption)
- Move ingested food towards the large intestine and rectum
Types of muscle contractions in the small intestine
- Segmentation contractions: Mix the chyme, and expose it to pancreatic and intestinal juices/expose to brush border
- Peristaltic contractions: Propel chyme along the small intestine toward the large intestine
Formation of gallstones
Cholelitiasis
Inflammation caused by the formation of gallstones
Cholesystitis
Gallbladder removal
Cholecystectomy
