HANDOUT 2 GIT

What is the main purpose of gastrointestinal secretions?

Where are organic materials that secretory cells synthesize stored before secretion?

What represents invaginations of the epithelium in the submucosa in the small intestine?

Which segment of the GI tract usually stimulates glandular secretions in response to the presence of food?

What type of glands are found at the lower part of the esophagus?

Where are water and electrolytes taken from before being secreted by secretory cells?

What is the main function of the mucus secreted by the mucus-secreting cells in the stomach?

What is the primary role of the intrinsic factor secreted by parietal cells?

Which mechanism is responsible for the active secretion of H+ by parietal cells into the canaliculus?

What is the net result of the reactions leading to HCl secretion in the stomach?

What is the main function of gastric mucus in protecting the stomach?

Which hormone acts on parietal cells to increase HCl secretion?

What is secreted by peptic (chief) cells and mucus cells in the stomach?

What is secreted by enterochromaffin-like cells in response to vagal stimulation and local inflammation?

What is released from paracrine cells in the mucosa and acts on parietal cells to decrease cAMP and decrease HCl secretion?

What is secreted from G cells of the pyloric glands into blood, and acts on parietal cells to increase HCl secretion?

What is secreted by G cells of the pyloric glands to maintain growth of mucosal cells?

What is the main function of saliva?

What is the average rate of saliva secretion during sleep?

How does sympathetic stimuli affect glandular secretion?

Which gland secretes around 70% of the saliva?

What is the predominant type of secretion from the parotid glands?

How does saliva facilitate swallowing?

What is the pH of saliva during resting secretion?

What induces the unconditioned salivary reflex?

'HCO3- secretion into the duct, partly by exchange of HCO3- for Cl- and may result also by an active transport of HCO3-' Refers to:

What increases the hydrostatic pressure inside acinar cells?

What is the function of Secretin in the regulation of pancreatic secretion?

What is the primary role of Pancreatic polypeptide in regulating pancreatic secretions?

What is the role of CCK (Cholecystokinin) in regulating pancreatic secretions?

What stimulates local reflexes and long reflexes leading to increased gastric secretion?

What causes maintenance of pH not to fall below 3 in the stomach?

What is the primary function of Pancreatic amylase?

What is the primary role of Lipase in pancreatic secretion?

What is the major stimulant of water and HCO3- secretion in pancreatic secretions?

Which hormone inhibits acid secretions in the intestine?

What enzymes are stored as inactive enzymes in zymogen granules and become activated in the duodenum?

Where are the primary bile acids synthesized?

What is the function of bile salts in the small intestine?

What is the role of the hormone secretin in bile secretion?

What is the main function of the gallbladder in bile storage?

How are the primary bile acids transformed into bile salts?

What causes the contraction of the gallbladder and relaxation of the sphincter of Oddi during a meal?

What is the main function of hepatocytes in relation to bile synthesis and secretion?

What happens to bile salts in the terminal ileum?

Where are water and electrolytes taken from before being secreted by secretory cells?

What is the primary function of saliva?

What represents invaginations of the epithelium in the submucosa in the small intestine?

What is the main function of the mucus secreted by the mucus-secreting cells in the stomach?

What contains organic materials that secretory cells synthesize, which are stored in vesicles and then secreted upon stimulation?

What is secreted by G cells of the pyloric glands into blood, and acts on parietal cells to increase HCl secretion?

What is the net movement of water, electrolytes, and proteins into the lumen of salivary ducts?

What is the role of acinar cells in salivary gland secretion?

What is the primary role of the duct cells during the flow of saliva through the ducts?

Which process results in a change in the ionic composition of saliva?

What is the approximate daily amount of secretion by saliva?

During resting secretion, what is the approximate pH of saliva?

What is the main function of saliva in relation to digestion?

What causes stimulation of salivation by thinking about, seeing, smelling, or hearing about pleasant food?

What is the primary function of lysozyme in saliva?

What is the function of mucus in saliva?

What effect does an increase in sympathetic activity have on salivation?

What induces activation of pressure receptors leading to unconditioned salivary reflex?

What is the primary function of the liver?

What is the role of the space of Disse in the liver?

What is the transformation process of bilirubin in the intestine?

How are bile salts synthesized by the liver stored and modified?

What is the primary function of bile in the small intestine?

What stimulates the contraction of the gallbladder and relaxation of the sphincter of Oddi during a meal?

What is the process by which bile salts are reabsorbed and recirculated in the body?

How are primary bile acids transformed into secondary bile acids in the intestine?

What is the primary function of bile acids in the small intestine?

What is the term for the transformation of cholic acid into deoxycholic acid and chenodeoxycholic acid into lithocholic acid?

What is secreted from G cells of the pyloric glands into blood, and acts on parietal cells to increase HCl secretion?

What is secreted from paracrine cells in the mucosa and acts on parietal cells to decrease cAMP and decrease HCl secretion?

What is the main function of HCl in the stomach?

What is the role of gastric mucus in protecting the stomach?

Which mechanism is responsible for the active secretion of H+ by parietal cells into the canaliculus?

What is the primary function of intrinsic factor secreted by parietal cells?

What causes the decrease in pH during gastric secretions?

What is the main role of saliva in oral hygiene?

What represents the main function of bicarbonate in gastric secretion?

What is the net result of the reactions leading to HCl secretion in the stomach?

What is the primary role of gastrin in gastric secretions?

Which hormone acts on parietal cells to decrease HCl secretion?

What is secreted by G cells of the pyloric glands to maintain growth of mucosal cells?

What is the function of pepsin in the stomach?

What stimulates the contraction of the gallbladder and relaxation of the sphincter of Oddi during a meal?

What is the net result of the reactions leading to HCl secretion in the stomach?

Which hormone inhibits acid secretions in the intestine?

What represents invaginations of the epithelium in the submucosa in the small intestine?

What induces the unconditioned salivary reflex?

What is secreted from paracrine cells in the mucosa and acts on parietal cells to decrease cAMP and decrease HCl secretion?

Where are organic materials that secretory cells synthesize stored before secretion?

'HCO3- secretion into the duct, partly by exchange of HCO3- for Cl- and may result also by an active transport of HCO3-' refers to:

'At high rates: HCO3- is high and Cl- is low.' refers to:

'At low rates: HCO3- is low and Cl- is high.' refers to:

What effect does an increase in sympathetic activity have on salivation?

What represents invaginations of the epithelium in the submucosa in the small intestine?

Gastrointestinal secretions are not influenced by the presence of food in the GI tract.

The primary function of gastric mucus is to aid in the digestion of food.

The space of Disse in the liver has a primary role in bile secretion.

Parotid glands mainly secrete mucus to aid in lubricating the mucosa.

Sympathetic activity has no effect on salivation.

The space of Disse is involved in the exchange of substances between hepatocytes and blood vessels.

Sympathetic stimuli can cause a moderate decrease in glandular secretion.

The primary function of saliva is to begin the digestion of proteins in the mouth.

The net result of the reactions leading to HCl secretion in the stomach is a decrease in the pH of the stomach.

The rate of saliva secretion during sleep is approximately 0.5ml/min.

The parotid glands secrete about 70% of the saliva and the type of secretion is mixed.

Stimulation of salivation can be induced by unconditioned salivary reflex, which occurs by stimulation of chemo-receptors and pressure-receptors in the stomach.

The pH of saliva during resting secretion is around 4.0.

Both sympathetic and parasympathetic nervous systems increase salivation by the same mechanisms.

The formation of primary saliva increases as much as 20 folds during maximal stimulation, resulting in a relative reduction of the reabsorptive and secretory activity of the duct cells.

The acinar cells are rich in endoplasmic reticulum (ER) and Golgi apparatus, providing sufficient energy supply for transport of nutrients.

Lysozyme in saliva acts as an enzyme that synthesizes certain bacteria.

The final saliva is a hypertonic solution due to a higher absorption rate of Na+ and Cl- than secretion of K+ and HCO3- by tubular cells.

The liver synthesizes two primary bile acids from cholesterol: cholic acid and chenodeoxycholic acid.

Bile salts are usually secreted as bile acids rather than as bile salts.

The primary bile secretion is hypotonic and contains Na+, K+, and Cl-.

During meals, the gallbladder is contracted and the sphincter of Oddi is relaxed, resulting in bile flowing into the intestine.

The entire bile salt pool is recirculated once during a normal meal, known as the enterohepatic circulation.

About 40% of bile salts are lost daily into feces.

Cholic acid is transformed into lithocholic acid by the activity of bacteria in the intestine.

Biliverdin is transformed into bilirubin and secreted in bile as conjugated with glucoronide, sulfate, and other substances.

Bile acts as a solvent to emulsify lipids and make them insoluble in the lumen of the intestine.

The environment in the lumen of the intestine is an aqueous environment in which lipids are readily soluble.

The space between sinusoid and hepatocytes is called the space of Disse, where lymphatic circulation takes place.

Jaundice is caused by the presence of low concentration of bilirubin in the extracellular space.

Excess of acids causes feed back inhibition of gastric secretions by 2 ways: Reduction of gastrin release and initiation of inhibitory reflexes.

Cephalic phase of control of gastric secretions is activated before food reaches the stomach.

Caffeine and alcohol can stimulate acid secretions even when no food is present in the stomach.

The presence of chyme in the intestine usually inhibits gastric secretions.

The tubular glands in the submucosa of the duodenum secrete mucus, water, and electrolytes.

Local neural mechanisms that activate intestinal secretions are mediated by Ach and VIP neurons.

Pancreatic enzymes are synthesized by duct cells and stored in zymogen granules.

Pancreatic amylase is responsible for converting disaccharides into polysaccharides.

Bile salts are synthesized by acinar cells and stored in zymogen granules.

Carbonic Anhydrase (CA) catalyzes the reaction: H2O + CO2 → H2CO3  H+ + HCO3-.

Parasympathetic stimulation is excitatory via Vagal stimulation, leading to the release of Ach, VIP, and GRP (Gastrin releasing peptide) in pancreatic secretion regulation.

Cholecystokinin (CCK) inhibits the release of enzymes by its inhibitory effects on the release of Ach from enteric nervous system.

Saliva plays a role in facilitating movements of the lips and tongue, aiding in speech.

Esophageal secretion consists of mainly complex mucus glands that produce acidic secretions.

Gastric mucus functions to prevent proteolytic enzymes from acting on the mucosa.

Parietal cells in the stomach secrete intrinsic factor and pepsinogen.

Active secretion of H+ by H+/K+ pump into the canaliculus is responsible for Cl- transport during HCl secretion.

The concentration of H+ in the canaliculus during gastric secretions is about 3 thousand times that in blood.

Pepsinogen is secreted by peptic (chief) cells and is already in its active form when secreted.

Gastrin has a trophic effect on gastric mucosa to inhibit the growth of mucosal cells.

Somatostatin released from paracrine cells in the mucosa decreases HCl secretion by increasing cAMP.

Histamine secreted by enterochromaffin-like cells activates parietal cells via H2 receptor to decrease HCl secretion.

Regulation of pepsinogen secretion is not directly influenced by Ach, Gastrin, or HCl.

Pancreatic polypeptide plays a primary role in inhibiting pancreatic secretion.