Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
63 Cards in this Set
- Front
- Back
|
Types of Secretory Glands
Single Cell - m______ cells or g______ cells Simple - indentations in epithelium (crypts of L________) Tubular - acid secreting o______ gland Complex - salivary, pancreas |
Types of Secretory Glands
Single Cell - mucous cells or goblet cells Simple - indentations in epithelium (crypts of Lieberkühn) Tubular - acid secreting oxyntic gland Complex - salivary, pancreas |
|
|
Control of Secretions
L____ - tactile, distention, irritation R_____ - nervous input Hormonal - G.I. hormones Parasympathetic Stim. - incr rate of secretion Sympathetic Stim. - incr or decr rate of secretion |
Control of Secretions
Local - tactile, distention, irritation Reflex - nervous input Hormonal - G.I. hormones Parasympathetic Stim. - incr rate of secretion Sympathetic Stim. - incr or decr rate of secretion |
|
|
Basic Mechanism of Secretion
Secrete substance – via ___cytosis Secrete water and electrolytes to move substance into target area |
Basic Mechanism of Secretion
Secrete substance – via exocytosis Secrete water and electrolytes to move substance into target area |
|
|
Total daily secretion volume of alimentary tract
|
6700ml
|
|
|
Mucus Composition - Properties
Thick secretion that is mainly water, electrolytes and g_______________ Essential for digestion because – Adherent - sticks to food Body - coats well Low resistance - lubrication Self adherent - sticks together Resistant to digestion Buffering capacity |
Mucus Composition - Properties
Thick secretion that is mainly water, electrolytes and glycoproteins Essential for digestion because – Adherent - sticks to food Body - coats well Low resistance - lubrication Self adherent - sticks together Resistant to digestion Buffering capacity |
|
|
Two types of secretion –
Serous - watery secretion, contains an alpha-_______ (ptyalin) Mucous - contains _____ - lubrication |
Two types of secretion –
Serous - watery secretion, contains an alpha-amylase (ptyalin) Mucous - contains mucin - lubrication |
|
|
Secrete 800-____ ml/day of saliva
Maximum rate of secretion: 4 ml/min |
Secrete 800-1500 ml/day of saliva
Maximum rate of secretion: 4 ml/min |
|
|
Formation and Secretion of Saliva
Two Stages A_____ - primary secretion similar to plasma (Cl- is principle ion that is secreted actively, not Na+) Salivary D____ - modified as it passes through ducts |
Formation and Secretion of Saliva
Two Stages Acini - primary secretion similar to plasma (Cl- is principle ion that is secreted actively, not Na+) Salivary Ducts - modified as it passes through ducts |
|
|
Parotid glands make serous saliva
Buccal glands make ______ saliva |
mucous
|
|
|
Ionic composition depends upon rate of secretion. Resting composition is:
Na+ - 0.1 x plasma (15 mEq/L) Cl- - 0.15 x plasma (15 mEq/L) K+ - 7 x plasma (30 mEq/L) HCO-3 - 3 x plasma (70 mEq/L) |
Ionic composition depends upon rate of secretion. Resting composition is:
Na+ - 0.1 x plasma (15 mEq/L) Cl- - 0.15 x plasma (15 mEq/L) K+ - 7 x plasma (30 mEq/L) HCO-3 - 3 x plasma (70 mEq/L) |
|
|
Saliva is ____tonic
|
Saliva is hypotonic
|
|
|
Loss of saliva from body can lead to _+ depletion (aldosterone)
|
Loss of saliva from body can lead to K+ depletion (aldosterone)
|
|
|
Effect of Secretory Rate on Ionic Composition of Saliva
Saliva is always hypotonic, but its __________ increases (and nearly reaches 300 mOsm/L) as flow rate increases. |
Effect of Secretory Rate on Ionic Composition of Saliva
Saliva is always hypotonic, but its osmolarity increases (and nearly reaches 300 mOsm/L) as flow rate increases. |
|
|
Saliva Destroys bacteria - proteolytic enzymes (lysozyme)
- ____cyanate - antibodies |
Saliva Destroys bacteria - proteolytic enzymes (lysozyme)
- thiocyanate - antibodies |
|
|
_________ - (absence of saliva)
|
Xerostomia - (absence of saliva)
|
|
|
Nervous Regulation of Salivary Flow
___________ stimulation directly increases salivation However, it can decrease a____________ stimulated salivation because it limits blood flow. |
Nervous Regulation of Salivary Flow
Sympathetic stimulation directly increases salivation However, it can decrease acetylcholine stimulated salivation because it limits blood flow. |
|
|
Drooling
Treatment: - anticholinergics - surgical removal of the s_________ glands and retropositioning sub__________ ducts. - Margin between drooling and xerostomia is small |
Drooling
Treatment: - anticholinergics - surgical removal of the sublingual glands and retropositioning submandibular ducts. - Margin between drooling and xerostomia is small |
|
|
Xerostomia - dry mouth.
Causes: - drug related - insufficient capillary perfusion - _________ treatment (aplasia of glands) - autoimmune disease |
Xerostomia - dry mouth.
Causes: - drug related - insufficient capillary perfusion - radiation treatment (aplasia of glands) - autoimmune disease |
|
|
Cystic Fibrosis - salivary Ca+, Na+, and protein are elevated (also true for bronchial secretions, pancreatic juice, and sweat).
Chloride secretion is essential for cell secretion. CF patients lack chloride transporter (CFTR ) CFTR = ______ ________ _____________ ____________ ________ |
Cystic Fibrosis - salivary Ca+, Na+, and protein are elevated (also true for bronchial secretions, pancreatic juice, and sweat).
Chloride secretion is essential for cell secretion. CF patients lack chloride transporter (CFTR ) CFTR = cystic fibrosis transmembrane conductance regulator |
|
|
Primary aldosteronism - (excess aldosterone)
salivary ____ close to zero salivary __ increases to high levels |
Primary aldosteronism - (excess aldosterone)
salivary NaCl close to zero salivary K+ increases to high levels |
|
|
Two types glands –
Gastric - HCl (ox______) pepsinogen intrinsic factor mucus rennin (chymosin) P______ - gastrin mucus (sm. amounts pepsinogen) |
Two types glands –
Gastric - HCl (oxyntic) pepsinogen intrinsic factor mucus rennin (chymosin) Pyloric - gastrin mucus (sm. amounts pepsinogen) |
|
|
Gastric (oxyntic) Gland
Three cell types - ______ neck cells - mucus ______ cells (chief cells) - pepsinogen - rennin _________ cells - HCl - intrinsic factor |
Gastric (oxyntic) Gland
Three cell types - Mucous neck cells - mucus Peptic cells (chief cells) - pepsinogen - rennin Parietal cells - HCl - intrinsic factor |
|
|
Mechanism of HCl Secretion
H+/K+ATPase or "proton pump" in cannalicular membrane is key player. ATPase is m________-dependent ATPase is not inhibited by o______ |
Mechanism of HCl Secretion
H+/K+ATPase or "proton pump" in cannalicular membrane is key player. ATPase is magnesium-dependent ATPase is not inhibited by ouabain |
|
|
Rennin (Ch______)
Proteolytic enzyme - causes milk to curdle in stomach Milk retained in stomach and released more slowly Rennin secretion - maximal first few days after birth. Replaced by secretion of ______ as major gastric protease Secreted as inactive proenzyme (prochymosin) that is activated on exposure to acid |
Rennin (Chymosin)
Proteolytic enzyme - causes milk to curdle in stomach Milk retained in stomach and released more slowly Rennin secretion - maximal first few days after birth. Replaced by secretion of pepsin as major gastric protease Secreted as inactive proenzyme (prochymosin) that is activated on exposure to acid |
|
|
Gastric secretion is stimulated by neural, paracrine and endocrine mechanisms
Acetylcholine - HCl secretion - mucus, pepsinogen, and gastrin Histamine - HCl secretion Gastrin - HCl secretion (____x more powerful compared to histamine) |
Gastric secretion is stimulated by neural, paracrine and endocrine mechanisms
Acetylcholine - HCl secretion - mucus, pepsinogen, and gastrin Histamine - HCl secretion Gastrin - HCl secretion (1500x more powerful compared to histamine) |
|
|
Regulation of Gastrin Secretion
Vagal control Gastrin secretion not blocked by a_______ G______ _________ p______ - stimulates gastrin release from G-cell S___________ - inhibits gastrin release from G-cell Antrum acidification - pH <_ inhibits gastrin release Small peptides and amino acids - directly stimulate gastrin release from G-cell |
Regulation of Gastrin Secretion
Vagal control Gastrin secretion not blocked by atropine Gastrin releasing peptide - stimulates gastrin release from G-cell Somatostatin - inhibits gastrin release from G-cell Antrum acidification - pH <3 inhibits gastrin release Small peptides and amino acids - directly stimulate gastrin release from G-cell |
|
|
Regulation of Histamine Secretion
Gastrin and acetylcholine stimulate histamine release from _______________-____ (ECL) cells ECL cells are a specialized endocrine cell in gastric mucosa Proliferation of ECL cells occurs in association with hypergastrinemic states Gastrin-secreting _______ Long term therapy with _____ that block acid secretion |
Regulation of Histamine Secretion
Gastrin and acetylcholine stimulate histamine release from enterochromaffin-like (ECL) cells ECL cells are a specialized endocrine cell in gastric mucosa Proliferation of ECL cells occurs in association with hypergastrinemic states Gastrin-secreting tumors Long term therapy with drugs that block acid secretion |
|
|
Histamine ___________ effects of gastrin and acetylcholine. H2 blockers _________ secretory responses to both acetylcholine and gastrin.
Acetylcholine ___________ effects of gastrin and histamine. Atropine __________ secretory effects of histamine and gastrin. |
Histamine potentiates effects of gastrin and acetylcholine. H2 blockers attenuate secretory responses to both acetylcholine and gastrin.
Acetylcholine potentiates effects of gastrin and histamine. Atropine attenuates secretory effects of histamine and gastrin. |
|
|
Gastric Phase
Accounts for __% of acid response to a meal Increased pH - gastrin release ** Distention - gastrin release ** Ach stimulation of HCl * Peptides / AA - gastrin release ** * blocked by ________ ** blocked by acidification of _____ |
Gastric Phase
Accounts for 60% of acid response to a meal Increased pH - gastrin release ** Distention - gastrin release ** Ach stimulation of HCl * Peptides / AA - gastrin release ** * blocked by atropine ** blocked by acidification of antrum |
|
|
Intestinal Phase
Accounts for __% of acid response to a meal Distention of small intestine - stimulates acid secretion (entero_______ - postulated hormone) Amino acids - circulating amino acids stimulate acid secretion via direct effect on parietal cell |
Intestinal Phase
Accounts for 10% of acid response to a meal Distention of small intestine - stimulates acid secretion (enterooxyntin - postulated hormone) Amino acids - circulating amino acids stimulate acid secretion via direct effect on parietal cell |
|
|
Before meal - pH is low - acid secretion is suppressed
Acid stimulates ____________ release (which decreases gastrin secretion) ____ has direct effect to suppress parietal cell secretion |
Before meal - pH is low - acid secretion is suppressed
Acid stimulates somatostatin release (which decreases gastrin secretion) Acid has direct effect to suppress parietal cell secretion |
|
|
Describe acid secretion and serum gastrin with pernicious anemia
|
no acid
high gastrin |
|
|
Describe acid secretion and serum gastrin with Zollinger-Ellison syndrome
|
high acid
high gastrin |
|
|
Gastric ulcers - main problem is decreased ability of ______ to protect itself
|
Gastric ulcers - main problem is decreased ability of mucosa to protect itself
|
|
|
Duodenal ulcers - main problem is exposure to increased amounts of ____ and ______
|
Duodenal ulcers - main problem is exposure to increased amounts of acid and pepsin
|
|
|
Duodenal ulcer patients often have 2-3x more ________ cells than normal
|
Duodenal ulcer patients often have 2-3x more parietal cells than normal
|
|
|
Increased acid secretion lowers plasma _______.
|
Increased acid secretion lowers plasma gastrin.
|
|
|
H+ back-leaks into mucosa in exchange for Na+. This is a forerunner to gastric _____
Decreased cell pH leads to cell death Damaged mast cells (ECL cells) leak histamine Viscous cycle - Histamine .. vascular damage .. local ischemia .. greater leakage of H+.. more cell death ... |
H+ back-leaks into mucosa in exchange for Na+. This is a forerunner to gastric ulcer
Decreased cell pH leads to cell death Damaged mast cells (ECL cells) leak histamine Viscous cycle - Histamine .. vascular damage .. local ischemia .. greater leakage of H+.. more cell death ... |
|
|
H. pylori found in 95% patients with DU and 100% patients with GU (when ______, ______, ______ are eliminated)
|
H. pylori found in 95% patients with DU and 100% patients with GU (when alcohol, aspirin, NSAIDS are eliminated)
|
|
|
Helicobacter pylori
High u______ activity - high NH4+ activity - can withstand acid environment - _____ damages epithelial cells (GU) - Increases acid secretion (_U) |
Helicobacter pylori
High urease activity - high NH4+ activity - can withstand acid environment - NH4+ damages epithelial cells (GU) - Increases acid secretion (DU) |
|
|
H2 receptor blockers - R_________ (Zantac)
- ___________ (Tagamet) |
H2 receptor blockers - Rantidine (Zantac)
- Cimetidine (Tagamet) |
|
|
Proton pump inhibitors - ___________ (Prilosec)
(Treatment of Peptic Ulcers) |
Proton pump inhibitors - Omeparazole (Prilosec)
(Treatment of Peptic Ulcers) |
|
|
Surgical (rare) - v_______
- a______omy (Treatment of Peptic Ulcers) |
Surgical (rare) - vagotomy
- antrectomy (Treatment of Peptic Ulcers) |
|
|
Internal Structure of Pancreas
_____ - grape-like clusters of cells that store and secrete digestive enzymes Ducts - secrete ___________ --Inter______ ducts - receive secretions from acini --Intra_______ ducts - receive fluid from intercalated ducts |
Internal Structure of Pancreas
Acini - grape-like clusters of cells that store and secrete digestive enzymes Ducts - secrete bicarbonate Intercalated ducts - receive secretions from acini Intralobular ducts - receive fluid from intercalated ducts |
|
|
Trypsin – cleaves p______ to polypeptides
Chymo_______ - cleaves proteins to polypeptides |
Trypsin – cleaves proteins to polypeptides
Chymotrypsin - cleaves proteins to polypeptides |
|
|
Carboxypeptidase – cleaves polypeptides to __
|
Carboxypeptidase – cleaves polypeptides to AA
|
|
|
Pancreatic lipase -
fat --> _____ _____ +monoglycerides |
Pancreatic lipase -
fat fatty acids +monoglycerides |
|
|
Phospholipase -
phospholipids --> _____ ____ |
Phospholipase -
phospholipids --> fatty acid |
|
|
Cholesterol esterase -
cholesterol esters --> _____ ____ |
Cholesterol esterase -
cholesterol esters --> fatty acid |
|
|
Why Doesn’t the Pancreas Digest Itself?
|
Pancreatic proteolytic enzymes are stored and secreted in an inactive form - (also, a trypsin inhibitor is present in cells)
trypsinogen --> trypsin chymotrypsinogen --> chymotrypsin procarboxypeptidase --> carboxypeptidase |
|
|
Trypsinogen --> Trypsin with what enyzme?
|
Enterokinase
Enterokinase - located on intestinal mucosal cells |
|
|
Trypsin - autocatalytic activation
- activates - c_______________, - p__________________ - t___________ |
Trypsin - autocatalytic activation
- activates - chymotrypsinogen, - procarboxypeptidase - trypsinogen |
|
|
Acute pancreatitis -
- a primary lack of _______ inhibitor - not enough ________ inhibitor is present |
Acute pancreatitis -
- a primary lack of trypsin inhibitor - not enough trypsin inhibitor is present |
|
|
Secretin induced ___________ secretion neutralizes acid chyme creating optimal conditions (pH = 7-8) for digestive enzymes -
|
Secretin induced bicarbonate secretion neutralizes acid chyme creating optimal conditions (pH = 7-8) for digestive enzymes -
|
|
|
Secretin is nature’s _________
|
Secretin is nature’s antiacid
|
|
|
HCO3- moves out of cell in exchange for ___.
|
HCO3- moves out of cell in exchange for Cl-.
|
|
|
Rate of HCO3- secretion is dependent upon luminal ___ concentration.
Na+ moves down electrochemical gradient. Water moves into lumen establishing osmotic equilibrium. (Pancreatic juice is always ___tonic.) Secretin - acts to open ___ channels and thus increase secretion of bicarbonate. |
Rate of HCO3- secretion is dependent upon luminal Cl- concentration.
Na+ moves down electrochemical gradient. Water moves into lumen establishing osmotic equilibrium. (Pancreatic juice is always isotonic.) Secretin - acts to open Cl- channels and thus increase secretion of bicarbonate. |
|
|
Secretin released when pH < ___.
|
Secretin released when pH < 4.5.
|
|
|
During meal pH rarely < ___ or ___.
|
During meal pH rarely < 3.5 or 4.0.
|
|
|
Chronic pancreatitis - (multiple shared causes)
_______ - most common cause in adults cystic fibrosis - most common cause in _________ |
Chronic pancreatitis - (multiple shared causes)
alcohol - most common cause in adults cystic fibrosis - most common cause in children |
|
|
Acute pancreatitis - (multiple shared causes)
__________ - most common cause |
Acute pancreatitis - (multiple shared causes)
gallstones - most common cause |
|
|
Brunner’s glands secrete an alkaline mucus.
Compound mucus gland in duodenum Protects mucosa from acid chyme Stimulated by local irritation - _____ (___) Inhibited by ____________ (__) Crypts of _________ - mostly secrete water -like fluid - 1800 ml/day |
Brunner’s glands secrete an alkaline mucus.
Compound mucus gland in duodenum Protects mucosa from acid chyme Stimulated by local irritation - vagus (Ach) Inhibited by sympathetics (NE) Crypts of Lieberkühn - mostly secrete water -like fluid - 1800 ml/day |
|
|
Large intestine also contains crypts of Lieberkühn but there are no _____ or enzymes.
Crypts mainly secrete alkaline mucus Mucus secretion increased by _______________ stimulation |
Large intestine also contains crypts of Lieberkühn but there are no villi or enzymes.
Crypts mainly secrete alkaline mucus Mucus secretion increased by parasympathetic stimulation |
