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130 Cards in this Set
- Front
- Back
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What does the Exocrine (secretory) glands or secretory cells of teh GI tract secrete (into the GI lumen)?
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DIGESTIVE ENZYMES
MUCUS Hydrochloric acid (HCL) Water and electrolytes Intrinsic factor |
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List the Phases of GI digestion/secretion
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CEPHALIC phase
GASTRIC phase INTESTINAL phase |
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What happens in the Cephalic Phase?
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Food is NOT in the GI Tract
Food is in the GI tract |
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In the Cephalic phase, what happens when teh food is NOT in the GI tract?
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Conditional reflex (Pavlov's reflex)
small sight thoughts of food |
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In the Cephalic phase, what happens when food is in the GI tract?
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taste of food (food in teh mouth)
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What happens in the gastric phase?
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food is in the stomach
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What happens in the Intestinal phase?
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food in the intestine
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What is the regulation of GI secretion?
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Neural Control
GI hormones |
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what are the two types of Neural control?
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Enteric Nervous System
Autonomic Nervous system |
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Parasympathetic stimultion increases or decrease the rate of GI secretion
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increase
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What does the sympathetic stimulation cause?
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DUAL EFFECT
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The DUAL EFFECT of Sympathetic stimulation is to increase secretion, and may decrease secretion if secretion is already increased by parasympathetic/hormonal stimulation.
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TRUE
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List teh GI homrones of GI secretion
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Gastrin
Cholecystokinin Secretin Gastric inhibitory peptide (GIP) somatostatin |
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What is the function of Salivary glands?
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Salivary secretion
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What is the daily secretion of Salivary secretion?
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800-1500 ml (avr. 1000 ml)
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Which gland has Mucous/Serous type of saliva?
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Submandicular
Sublingual |
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Which gland has Serous type of saliva?
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Parotid
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Which gland has Mucous type of Saliva?
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Buccal
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Which gland has the highest total secreted saliva?
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Parotid and Submandibular
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Which has the lowest total secreted saliva?
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Buccal
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List the function of Saliva
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Lubrication
Protection Hygiene Digestion Excretory |
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List the composition of Saliva
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Water, Mucus (Mucin), Electrolytes
Enzymes Immunoglobulin Bactericidal Blood group antigens Sex steroids |
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Whare the enzympes of Saliva?
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ptyalin (a-amylase)
lingual lipase kallikrein |
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What is kallikrein?
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PRECURSOS FOR BRADYKININ- a strong vasodilator
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Which immunglobulin will you find in saliva?
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IgA
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Which bactericidal would you find in Saliva?
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lysozyme
Lactoferrin |
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When is saliva ISOTONIC and has neutral pH?
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The initial saliva
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When is saliva HYPOTONIC?
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Before entering the oral cavity, with pH 6-7 d/t electrolyte modification
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In the primary secretion of saliva, what are the primary secretion?
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Ptyalin
Mucus Extracellular fluid |
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In primary secretion, what are the electrolyte-- active secretion?
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Na+, K+
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Which INCREASE salivary secretion rate? Parasympathetic or Sympathetic Nervous system?
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BOTH will increase
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Which one is DOMINANT? Parasypathetic or Sympathetic?
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PSNS; lots of water secretion
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How does Parasympathetic increase salivation?
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via increase acinar and duct cell secretory activity and VASODILATION
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Why is the action of SNS weak?
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thick, viscous secretion
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What happens when SNS stimulates myoepithelial cell contraction?
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causes VASOCONSTRICTION
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What causes increase in K+ secretion adn Na+ reabsorption in the striated duct?
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Aldosterone
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TQ~ What are the Physiological stimulators of the salivary secretion?
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Conditional (Pavlovian) reflexes:
Chewing Tasting Smelling Nausea |
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TQ What are the Physiological inhibitors?
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Sleep
Fatigue Dehydration Fear |
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GASTRIC mucosa has two major types of tubular glands
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Oxyntic glands
Pyloric glands |
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List the cells of the Oxyntic glands
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Parietal cells
Chief cells Mucus cells |
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List the cells of the Pyloric glands
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Mucus cells
G cells |
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What does the parietal cells make?
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HCL, intrinsic factor
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What does the Chief cells make?
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pepsinogen
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What does the Mucus cells make?
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mucus
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What does the G cells make?
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GASTRIN (hormone)
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Gastric secretion has ____# phases
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Three
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The three phases of Gastric secretion are:
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Cephalic phase
Gastric Phase Intestinal phase |
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Which phase has the most total daily secretion of Gastric?
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Gastric phase
60-70% total daily secretion |
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Which phase has the lease total daily secretion of GAstric?
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Intestinal phase
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HYDROCHLORIC ACID (HCL) is produced by what type of cells?
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PARIETAL CELLS
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What is the function of hydrochloric acid?
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Bactericidal (prevents GI infection)
Denature polypeptides Pepsinogen --> Pepsin (pH <5) |
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PEPSINOGEN is produced by what cells?
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CHIEF CELLS
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What is the function of Pepsin?
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initiates protein digestion
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What is teh function of GASTRIC lipase?
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Fat digestion
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What cells produce Mucus and HCO3?
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MUMUS CELLS
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What siteh the function of MUCUS and HCO3?
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GASTRIC MUCOSAL BARRIER -- protects gastric mucosa
Lubricates Chyme Buffers gastric acid |
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What cells produce the INTRINSIC FACTOR?
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PARIETAL CELLS
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What is the function of INTRINSIC FACTOR?
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Vit B12 absorption (deficit will cause pernicious anemia
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What causes the GASTRIC MUCOSAL barrier"?
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Alkaline pH 7 mucus layer (0.2) mm thick, which protects gastric mucosa
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List the compositions of Gastric juices
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Hydrochloric acid (HCL)
Pepsinogen Mucus and HCO3 Intrinsic factor |
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List the Gastric acid secretion
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BASAL SECRETION
STIMULATED SECRETION (post prandial) |
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STIMULATED secretion of Gastric secretion phases are:
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CEPHALIC
GASTRIC INTESTINAL |
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What stimulates secretion of Gastric ACID?
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Ach
gastrin histamine |
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What inhibits Gastric acid secretion?
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somatostatin
secretin |
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List the things that stiulates gastric acid secretion
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Ach
Histamine Gastrin |
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Ach DIRECTLY acts on what type of cells?
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Parietal cells
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Ach INDIRECTLY act on?
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indirectly act on stimulating gastrin and histamine release
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Histamine DIRECTLY act on
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paracrine mechanism
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Gastrin directly and indirectly is stimulated by?
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histamine release
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Note: Gastric secretion increase, reaches maximum, and then gradually decreases when the chyme entering the suodenum.
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NOTE
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When is gastric secretion the maximal during gastric phase?
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1 hour after a meal gastric secretion is maximal
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High or low pH lead to:
inhibits gastrin release (via negatie feedback mechanism) Stimulates release of somatostatin which diretly inhibits acid secretion |
Low pH (high acidity)
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What stimulates RELEASE OF SECRETIN and ENETROGASTRIC REFLEX in the duodenum?
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Chyme
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List the Chyme found during gastric phase
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acids
protein digestion product fat hyperosmotic or hypo-osmotic fluids |
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What happens when you release secretin during gastric phase?
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Secretin inhibits gastric acid secretion
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What happens in enetrogastric reflex?
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INHIBITS gastric SECRETION and stomach EMPTYING
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List the Stimuli for HCL secretion
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Neural: PSNA (Ach)
Paracrine: Histamine Endocrine: Gastrin (directly and indirectly) |
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What does Somatostatin inhibit?
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H+, histamine
gastrin secretion |
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Gastric acid secretion is inhibited by:
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Somatostatinn
Secretin GIP |
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What are the MOST inhbitors of Acid secretion?
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H, K-ATPase inhibts (proton pump blockers)
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What does the GASTRIC MUCOSAL BARRIER function as?
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The alkaline mucus layer lubricates chyme and buffers gastric acid
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Mucus + HCO3
Prostaglandins Mucosal blood flow Growth factors Are Protective or Damaging Factors? |
Protective Factors
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H+ and pepsin
H pylori NSAIDs Stress Smoking Alcohol Are Protective or Damaging Factors? |
Damaging Factors
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What is Peptic Ulcer Disease?
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Acids and pepsin damage mucosal barrier and cayse peptic ulcer disease
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What are the steps that lead to Peptic Ulcer disease?
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Damaged mucosal barrier--> H+ leaks into the mucosa--> cellular injury and death--> H+ damages mucosal mast cells--> stimulates histamine release --> histamine acts on the mucosal capillaries --> local ischemia, hypoxia, vascular stasis
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Gastric acid secretion is inhibited by:
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Somatostatinn
Secretin GIP |
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What happens when Pepsin leaks into the mucosa?
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Plasam proteins leak into the gastric lumen adn cause BLEEDING
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What are the MOST inhbitors of Acid secretion?
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H, K-ATPase inhibts (proton pump blockers)
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List the factors that cause peptic ulcer disease (damages mucosa)
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H. Pylori
Aspirin Bile acids |
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What does the GASTRIC MUCOSAL BARRIER function as?
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The alkaline mucus layer lubricates chyme and buffers gastric acid
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Mucus + HCO3
Prostaglandins Mucosal blood flow Growth factors Are Protective or Damaging Factors? |
Protective Factors
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Which factor that cause paptic ulcer disease involve:
produces NH4+ and various cytokines Increase H+ secretion |
H Pylori
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H+ and pepsin
H pylori NSAIDs Stress Smoking Alcohol Are Protective or Damaging Factors? |
Damaging Factors
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What is Peptic Ulcer Disease?
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Acids and pepsin damage mucosal barrier and cayse peptic ulcer disease
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What are the steps that lead to Peptic Ulcer disease?
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Damaged mucosal barrier--> H+ leaks into the mucosa--> cellular injury and death--> H+ damages mucosal mast cells--> stimulates histamine release --> histamine acts on the mucosal capillaries --> local ischemia, hypoxia, vascular stasis
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What happens when Pepsin leaks into the mucosa?
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Plasam proteins leak into the gastric lumen adn cause BLEEDING
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List the factors that cause peptic ulcer disease (damages mucosa)
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H. Pylori
Aspirin Bile acids |
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Which factor that cause paptic ulcer disease involve:
produces NH4+ and various cytokines Increase H+ secretion |
H Pylori
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Which peptic ulcer factor:
decrease mucosal production of prostaglandins (PGE2) by inhibiting cyclooxygenas (COX) and cause mucosal damage? PGs regular secertion of mucus + HCO3 and manintain blood flow |
Aspirin (NSAID)
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Which factor of Peptic ulcer disease involves:
increase H+ leaks into the mucosa? |
Biel acids
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The pancrease has ____% exocrine cells
& _______% of endocrine cells. |
90%, 10%
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List the Aqueous Component of the Pancreatic secretion
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by ductal cells HCO3, H2O, electrolytes
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What is the function of the AQUEOUS COMPONENT?
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optimize pH for digestive enzymes
Prevent ulceration |
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List the Enzymatic Component of Pancreatic secreion
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by acinar cells:
digestive enzymes (amylase, lipase, proteases) |
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What is the function of enzymatic component?
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digestion
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TQ! List the hormone that regular pancreatic secretion
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Secretin (nature's antacid)
Cholecystokinin (CCK) |
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List the stimuli for pancreatic Secretion
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Secretin
Cholescystokinin (CCK) |
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What is the stimuli for Secretin in pancreatic secretion?
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Acidic (pH < 4.5-5.0) HCl) chyme in the duodenum
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What is the primarily effect of Secretin?
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increase HCO3 FROM PANCREASE (DUCTAL CELLS) and LIVER
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What is Cholecystokinin (CCK) stimuli in pancreatic secretion?
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amino acids
some peptides fatty acids in teh Small intestine |
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What is the primarily effect of Cholecystokinin (CCK)?
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increase enzyme secretion
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What is the neural regulation used in pancreatic secretion?
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Ach
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What are the Ach stimuli for secretion of CCK in pancreatic secretion?
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peptides
amino acids (initiate neural reflexes) |
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What is the primarily effect of Ach in pancreatic secretion?
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increase enzyme, and squeous secretion
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Which regulator potentiates the secretory responses to CCK and secretin and maintains normal rates of pancreatic protein synthesis and stores of digestiec enzymes?
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Insulin
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Note: pancreatic enzyme secretion is able ot adapt to the diet. A high protein, low carb diet increase the proprotion of proteases and decreases the proportion of amylase
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NOTE
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Liver functions
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Carbohydrate metabolism
Protein metabolism Lipid Metabolism Synthesis and secretion of bile Breakdown of hormones, hemoglobin, toxic substances, ans most medicinal products (drug metabolism) synthesis of plasma proteins and blood coagulation factors Conversion of ammonia to urea Storage of glycogen, Vit B 12, iron and copper Erythropoiesis in 1st timester Body defense system |
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Which organ produces bile?
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Liver
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Bile is secreted by _______ and _______ cells
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hypatocytes
ductular epithelial cells |
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List what bile consists of:
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bile salts
phospholipids cholesterol bile pigments electrolytes water |
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Where is bile stored and concentrated?
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Gallbladder
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Where is STORED bile release?
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released into duodenum in reponse to a meal
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True or False: Bile participates in emulsification and digestion of ingested lipid material.
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True
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GALLBLADDER contraction is stimulated by ______ and________
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CCK and cholinergic vagal stimulation
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What does the small and large intestines perform what functions?
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secretion adn absorption functions
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What are the components of the Small intestine?
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1-2 L/day
Alkaline Isotonic H2O ENZYMES Electrolytes Mucus |
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What is the functions of Small intestine?
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Chyme Fluidity:
Digestion/Absorption/Motility Dilute Toxins Buffer |
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What is the components of the colon?
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o.2 L/day
Mucus K+, HCO3 |
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What is the neural control for Colon?
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ENTERIC NS and PSNS
-Tactile (Mucosa) - Distension (WAll) |
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What are the hormonal regulation for the colon?
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secretin- mucus secretion by Brunner's glands
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