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GI - Pt 3 Secretions Flashcards

1
Q

Serous (acinar) cells secrete [] & []

Mucus acinar cell secrete []

A

Serous (acinar) cells secrete water & bicarb

Mucus acinar cell secrete mucus

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2
Q

Salivary Secretions:

  • Almost totally under [] NS control
    • Primarily []
    • Secondarily []
  • What are the ~4 main secretions we covered?
A
  • Almost totally under Autonomic NS control
    • Primarily parasympathetic
    • Secondarily sympathetic
  • What are the ~4 main secretions we covered?
    • Salivary Amylase
    • Lingual lipase
    • Haptocorrin
    • Intrinsic Factor
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3
Q

Salivary Amylase:

  • Indentical to [] amylase
  • Its optimum resides around pH - []
  • Cleaves the interal [] [] [] []
A
  • Indentical to pancreatic amylase
  • Its optimum resides around pH - 7
  • Cleaves the interal alpha 1-4 glycosidic bonds
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4
Q

Lingual Lipase

  • secreted by the glands of the []
  • Begins digestion of []
  • Optimal pH resides around - [] []
A
  • secreted by the glands of the tongue
  • Begins digestion of triglycerides
  • Optimal pH resides around - acidic conditions
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5
Q

Haptocorrin

  • It is a []
  • Binds vitamin [] in the []/duodenum
    • so it protects B12 in [] environments.
  • VERY similar to [] []
    • This protects B12 in the []
A

Haptocorrin

  • It is a glycoprotein
  • Binds vitamin B12 in the stomach/duodenum
    • so it protects B12 in acidic environments.
  • VERY similar to Instrinsic Factor
    • This protects B12 in the intestines
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6
Q

Lubrication & protection salivary secretions:

  • [] - protect stomach from initial [] stress
  • [] aspect (bacteriocidal)
  • [] (IgA) - optimizing an immunological response against bacteria and virus
  • [] - chelates Iron
A
  • Mucus - protect stomach from initial food stress
  • Lyzozymal aspect (bacteriocidal)
  • Immunoglobin A (IgA) - optimizing an immunological response against bacteria and virus
  • Lactoferrin - chelates Iron
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7
Q

Dry Mouth

  • [] refers to chronic infectins of the buccal mucosa
    • Dissolution of [] components by [] acids produced by enzymatic actions of masses of []
A
  • Xerostomia refers to chronic infectins of the buccal mucosa
    • Dissolution of inorganic components by organic acids produced by enzymatic actions of masses of microorganism
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8
Q

Parotid Gland

  1. Largest [] gland
  2. Made of serous cells with produce []/[] and []
  3. At rest, produce [] of saliva volume
  4. Active, produces [] of saliva volume
A
  1. Largest salivary gland
  2. Made of serous cells with produce H2O/HCO3- and enzymes
  3. At rest, produce 25% of saliva volume
  4. Active, produces 80% of saliva volume
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9
Q

Submandibular Gland

  1. Unstimulated, accounts for [] of overall saliva volume
  2. It is a [] salivary gland
    1. [] is the major component
    2. Also has a [] component.
A
  1. Unstimulated, accounts for 70% of overall saliva volume
  2. It is a mixed salivary gland
    1. mucus is the major component
    2. Also has a serous component.
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10
Q

Sublingual Gland

  1. Mainly a [] gland
    1. contains a very minor [] portion
A
  1. Mainly a mucus gland
    1. contains a very minor serous portion
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11
Q

T/F

Saliva secreted by serous/mucus acinus is modified in the intercalated duct and not the striated duct?

A

FALSE

The modification of saliva happens in the stiated duct

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12
Q
  • Salivary glands receive a high blood flow which results in the production of a large volume of []
A

fluid

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13
Q
  • Salivary glands receive both [] and [] innervation
    • Parasympathetic is the [] component and is done by 2 nerves:
      • [] Nerve (VII)
      • [] (IX)
    • Sympathetic is the []component done through the [] spinal cord via the superior [] ganglion
A
  • Salivary glands receive both parasympathetic and sympathetic innervation
    • Parasympathetic is the major component and is done by 2 nerves:
      • Facial Nerve (VII)
      • Glossopharyngeal Nerve (IX)
    • Sympathetic is the minor component done through the thoracic spinal cord via the superior cervical ganglion
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14
Q

For salivary glands, even though they receive Para/Symp innervation, [] innervation is more important because they are somehow [] to the salivary glands. So, if this innervation is cut off…the glands would []

A

For salivary glands, even though they receive Para/Symp innervation, parasympathetic innervation is more important because they are somehow nutritive to the salivary glands. So, if this innervation is cut off…the glands would “die”

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15
Q

Salivary glands, Autonomics regulate…

  1. secretions by acting on [] cells
  2. Blood flow by acting on [] networks
  3. Growth by acting directly on [] cells
A
  1. secretions by acting on myoepithelial cells
  2. Blood flow by acting on arteriolar networks
  3. Growth by acting directly on acinar cells
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16
Q

Parasympathetic flow of Salivary glands

  • Receptors - [] and []
  • [] of transport process
  • Contraction of [] cells
  • [] the blood vessels
  • [] the cellular activity resulting in [] of the cell.
A
  • Receptors - muscarinic and cholinergic
  • Activation of transport process
  • Contraction of myoepithelial cells
  • Vasodilate the blood vessels
  • Increase the cellular activity resulting in growth of the cell.
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17
Q

Sympathetic (w/ Para)

  • Uses [] receptors
  • Increases secretion, metabolism, and growht
  • With [] parasympathetic stimulation..
    • produces a more[] secretion
    • increases []
    • Causes [] - reduced [] secretions.
A
  • Uses B2 adrenergic receptors
  • Increases secretion, metabolism, and growth
  • With reduced parasympathetic stimulation..
    • produces a more viscous secretion (thicker), = nervous
    • increases mucus
    • Causes vasoconstriction - reduced serous secretions.
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18
Q

Salivary Flow

  1. [] [] [] (VIP), a [], is released at the [] end and mediates []
A

Vasoactive intestinal peptide (VIP), a neurocrine, is released at the postganglionic end and mediates vasodilation

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19
Q
  • Conditioned reflex like smell/taste –>
  • stimuli in the [] [] in the medulla Oblongata –>
  • Parasymp Nerves: [] (VII) & –> releases [] & [] –>
  • [] and Sailvary gland stimulation –>
  • In salivary gland: Increase in [] = Increase in [] –> Increase in metabolism, secretion, growth, myoepithelial contraction.
A
  • Conditioned reflex like smell/taste –>
  • stimuli in the Nucleii Salvatorii in the medulla Oblongata –>
  • Parasymp Nerves: Facial (VII) & Glossopharyngeal (IX) –> releases ACh & VIP –>
  • Vasodilation and Salivary gland stimulation –>
  • In salivary gland: Increase in IP3 = Increase in Ca2+ –> Increase in metabolism, secretion, growth, myoepithelial contraction.
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20
Q
  • Conditioned reflex like smell/taste –>
  • Sympathetic nerves T1/T2/T3 - release [] –>
  • Superior [] ganglion–> postgonglionic axons release [] at salivary gland that bind to [] [] receptors –> increase in [] = increase in [] –> increaes metabolism, cell contraction, secretion, growth.
A
  • Conditioned reflex like smell/taste –>
  • Sympathetic nerves T1/T2/T3 - release ACh –>
  • Superior Cervical ganglion–> postgonglionic axons release norepinephrine at salivary gland that bind to B2 adrenergic receptors –> increase in cAMP = increase in Ca2+ –> increaes metabolism, cell contraction, secretion, growth.
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21
Q

Saliva Compostion:

  • High [] concentration
  • Low []
  • Inorganic Composition:
    • K+ is always [] than plasma
    • Na+ is [] than plasma
    • CL- is [] than plasma
    • HCO3- is [] than plama (except at [] [])
A
  • High K+ concentration
  • Low Osmolarity
  • Inorganic Composition:
    • K+ is always greater than plasma
    • Na+ is less than plasma
    • CL- is less than plasma
    • HCO3- is greater than plama (except at low flow)
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22
Q

All ions in salivary acinus = the plasma [] of ions

A

concentration

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23
Q

T/F - all ion in the acinus are in equal concentration to the ionic concentration of the plasma

A

True

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24
Q

Striated Ductal Function

  • Reabsorb [] and []
  • Secrete [] and []
  • [] dependent
  • More [] and [] leaves than [] and [] enter
  • Epithelium is relatively [] to H2O
  • As saliva leaves the duct, it is []
A
  • Reabsorb Na+ and Cl-
  • Secrete K+ and HCO3-
  • Time dependent
  • More Na+ and Cl- leaves than K+ and HCO3- enter
  • Epithelium is relatively impermeable ot H2O
  • As saliva leaves the duct, it is hypotonic
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25
As flow past the salivary duct cells increase, the time for resorptive and secretory processes []; saliva moves toward []
As flow past the salivary duct cells increase, the time for resorptive and secretory processes **decreases**; saliva moves toward **i****sotonicity**
26
As salivary flow rate _increase_: * Na+ and Cl- concentrations in the lumen [] * [K+] in the lumen [] slightly * [HCO3-] in the lumen [] because its secretion is increased by the same [] that increase flow rate.
* Na+ and Cl- concentrations in the lumen **increase** * [K+] in the lumen **decreases** slightly * [HCO3-] in the lumen **increases** because its secretion is increased by the same **stimuli** that increase flow rate.
27
Even when salivary flow rate increase, Na+ and Cl- will [] reach their concentrations in the plasma.
Even when salivary flow rate increase, Na+ and Cl- will **never** reach their concentrations in the plasma.
28
* Increased Flow rate --\> Increased metabolism and Increased[] and [] production ---\> H+ and [] production * The H+ gets [], but the HCO3- does not...so pH of saliva will [].
* Increased Flow rate --\> Increased metabolism and Increased **CO2** and **H2O** production ---\> H+ and **HCO3-** production * The H+ gets **buffered**, but the HCO3- does not...so pH of saliva will **increase**.
29
2 functions of Esophageal mucus secretions:
Lubrication protection against gastric reflux
30
Intrinsic factor is secreted by [] cells.
Intrinsic factor is secreted by **parietal** cells.
31
What is present in higher concentration in the stomach: heptacorrin or intrinsic facto?
Intrinsic factor | (heptacorring is higher in saliva.)
32
The most ptent stimuli for HCl production by the parietal cells are: * [] - Enteric NS * [] - from G-cells * [] - paracrine relationship
* **Acetylcholine** - Enteric NS * **Gastrin** - from G-cells * **Histamine** - paracrine relationship
33
Gastrin release is inhibited as acid acts on the [] cell which then produces [] Inhibition of acid secretion is also mediated as acid in the duodenum releases [] which inhibits []cells production of acid
Gastrin release is inhibited as acid acts on the **Somatostatin** cell which then produces **somatostatin** Inhibition of acid secretion is also mediated as acid in the duodenum releases S**ecretin** which inhibits P**arietal** cells production of acid
34
Pepsinogen/Pepsin Secretion * Secreted by [] cells near base of Gastric [] * 2 types of pepsinogen Type I - []and Type II is found in the [] [] * Pepsinogen converts itself to pepsin at pH \< [] = []
* Secreted by **chief** cells near base of Gastric **Gland** - 2 types of pepsinogen Type I - **predominant** and Type II is found in the **Pyloric** region * Pepsinogen converts itself to pepsin at pH \< **5** = **Autocatalytic**
35
* Pepsin splits interior peptide bonds making it an []
endopeptidase
36
* [] is the most potent and important stimulator for pepsinogen/pepsin secretion * Acid triggers a local [] reflex stimulaitng chief cells * [] also stimulates chief cells to produce pepsinogen.
* **Acetylcholine** is the most potent and important stimulator for pepsinogen/pepsin secretion * Acid triggers a local **cholinergic** reflex stimulaitng chief cells * **Secretin** also stimulates chief cells to produce pepsinogen.
37
Haptocorrin Secretion * Secreted by the [] glands, thought to be by parietal cells * Associated with the []/[] [] Pump in some way. * Binds B12 in [] environment. B12: * Necessary cofactor in the maturation of [] * []can store B12 for up to 6 year supply * Abosprtion by the [] mucosa * If absent = [] []... associated with * Achlorhydria * Lack of [] cells
* Secreted by the **Gastric** glands, thought to be by **parietal** cells * Associated with the **H+/K+ Proton** Pump in some way. * Binds B12 in **acid** environment. B12: * Necessary cofactor in the maturation of **RBCs** * **Liver** can store B12 for up to 6 year supply * Abosprtion by the **ileal** mucosa * If absent = **Pernicious Anemia** associated with * Achlorhydria * Lack of **parietal** cells
38
Intrinsic Factor Secretion: 1. Secreted by [] cells 2. Is a [] 3. Binds B12 at a [] pH 4. Made in the [], but protects B12 in the [] 5. [] transporter in the [] that aborbs B12 bound to intrinsic factor.
1. Secreted by **parieta**l cells 2. Is a m**ucoprotein** 3. Binds B12 at a **nuetral** pH 4. Made in the **stomach**, but protects B12 in the **duodenum** 5. **Active** transporter in the **ileum** that absorbs B12 bound to intrinsic factor.
39
Mucus secretions: * 2 types of mucus * []: Fills the lumen * []: Coats the mucosa * Provides a physical and chemical barrer to both [] and [] enzyme contact
* 2 types of mucus * **Soluble**: Fills the lumen * **Insoluble**: Coats the mucosa * Provides a physical and chemical barrer to both **acid** and **digestive** enzyme contact
40
Peptic Ulcer Disease normally involves an increased acid secretion or bacterial infection by []
**H.Pylori**
41
Peptic Ulcer Disease: * Most often associate with interupting/inhibiting the dilatory actions of [] [] * NSAID - [] [] []-[] [] will inhibit Prostaglandin E2 --\> [] and restricted blood flow --\> restricts [] access to mucosa --\> [] barrier to acid on stomach lining.
* Most often associate with interupting/inhibiting the dilatory actions of **Prostaglandin E2** * NSAID - **non steroidal anti-inflammatory drugs** will inhibit Prostaglandin E2 --\> **vasoconstriction** and restricted blood flow --\> restricts **HCO3-** access to mucosa --\> **smaller** barrier to acid on stomach lining.
42
Peptic Ulcer Treatment: * Neutralization of acid with a [] [] as Antacid: * Peptobismol * Tums * Ralids * Mylants
weak base
43
Peptic Ulcer Treatment: * Specific treament: Blocking the [] type receptor blockers * decreases [] of parietal cells by [] * Or Inihibt secretion of H+ by the []/[] [] Pump in the [] membrane of parietal cells * Can lead to [] [] by decreasing levels []/[]Factor --\> decreased levels of B12 --\> [] RBCs
* Specific treament: Blocking the **H2** type receptor blockers * decreases **activation** of parietal cells by **histamine** * Inihibt secretion of H+ by the **H+/K+ Proton** Pump in the **apical** membrane of parietal cells * Can lead to **Pernicous Anemia** by decreasing levels **Heptacorrin/Instrinsic Factor** --\> decreased levels of B12 --\> **rounded** RBCs
44
Cephalic Phase - Effects on Gastric Acid Secretion * The vagus stimultes [] cells directly * [] is the neurotransmitter stimulating the release of gastrin via [] * If the vagus nerve is cut above the stomach...gastric acid secretion will []
* The vagus stimulates **parietal** cells directly * **ACh** is the neurotransmitter stimulating the release of gastrin via **GRP** * If the vagus nerve is cut above the stomach...gastric acid secretion will **stop**
45
Gastric Phase (Digestion) Effect on Gastric Secretion: * Neural input via * [] phase influence * [] reflex * Distention * Chemical changes in the stomach * Peptides, amino acids ([] and []) * Secretagogues * [], [], and []
* Neural input via * **Cephalic** phase influence * **Vaovagal** reflex * Distention * Chemical changes in the stomach * Peptides, amino acids (**Phenylalanine** and **Tryptophan**) * Secretagogues * **Calcium, Caffeine, alcohol**
46
Intestinal Phase & Gastric Secretions: * Very [] component to gastric secretions * Stimulated by products of [] digestion in the [] * Mediated by [] and []
* Very **minor** component to gastric secretions * Stimulated by products of **protein** digestion in the **duodenum** * Mediated by **Enterooxynitin** and **distention**
47
Enterooxynitin * Secreted by [] cells in the duodenum * Target is the [] Gland in the stomach, primarily p[] cells * Causes [] secretion
* Secreted by **Endocrine** cells in the duodenum * Target is the **Oxynitic** Gland in the stomach, primarily **parietal** cells * Causes **H+** secretion
48
Pancreatic Secretions: * Exocrine Secretions * []/Aqeuous component * Produced by [] cells * [] volume * Enzyme component * produced by [] cells * [] volume
* Exocrine Secretions * **HCO3-**/Aqeuous component * Produced by **ductal** cells * **High** volume * Enzyme component * produced by **Acinar** cells * **Low** volume
49
3 way to regulate pancrease exocrine secretion: 1. [] Polypeptide 2. [] Efferents 3. [] Efferents
1. **Pancreatic** Polypeptide 2. **Sympathetic** Efferents 3. **Parasympathetic** Efferents
50
Regulating Pancreatic Exocrine Secretions * Pancreatic Polypeptide * released in response to [] Acids * [] exocrine functions. * Sympathetic Efferents * [] exocrine secretions * Post-ganglionic fibers arise from: [] Plexus and Superior [] Plexus * Parasympathetic Efferents * Innervation comes from the[] nerve * Terminates at the [] * [] exocrine secretions.
* Pancreatic Polypeptide * released in response to **Amino** Acids * **Inhibits** exocrine functions. * Sympathetic Efferents * **Inhibit** exocrine secretions * Post-ganglionic fibers arise from: **Celiac** Plexus and Superior **Mesenteric** Plexus * Parasympathetic Efferents * Innervation comes from the **Vagus** nerve * Terminates at the **acini** * **Stimulates** exocrine secretions.
51
_Aqueous_ Pancreatic Secretions * [] with plasma * Cl- and HCO3- amounts vary [] due to [] [] present on membrane * Secreted by [] and centroacinar cells; set up by * Na+/K+ ATPase in [] membrane * [] Anhydrase * Regulation through [] initiated mechanism in the duodenum
* **Isotonic** with plasma * Cl- and HCO3- vary **inversely** due to **anion exchangers** present on membrane * Secreted by **ductal** and centroacinar cells; set up by * Na+/K+ ATPase in **basolateral** membrane * **Carbonic** Anhydrase * Regulation through **acid** initiated mechanism in the duodenum
52
Enzyme Component of Pancreatic Secretions * Types of Enzymes: Lipase, Amylase, and [] produced as [] precursors * Enzymes stored at [] granules near the [] membrane * Enzymes released by [] controlled by * [] input and [] input * Mediated through [] and [] in the duodenum
* Types of Enzymes: Lipase, Amylase, and **proteases** produced as **inactive** precursors * Enzymes stored at **zymogen** granules near the **apical** membrane * Enzymes released by **exocytosis** controlled by * **Neural** input and **hormonal** input * Mediated through **fat** and **protein** in the duodenum
53
Cephalic Phase & Pancreatic Secretion: * Vagal efferents synapse on acinus, primarily the [] cells * Drive [] of enzymes * [] can also drive secretion of enzymnes becuase its chemical structure is similar to CCK
* Vagal efferents synapse on acinus, primarily the **acinar** cells * Drive **secretion** of enzymes * **Gastrin** can also drive secretion of enzymnes becuase its chemical structure is similar to CCK
54
Gastric Phase and Pancreatic Secretions: * [] of stomach produces vagovagal reflex. * primarily acts to [] enzymatic secretion * Little effect on []/[] secretions (aqeuos)
* **Distention** of stomach produces vagovagal reflex. * primarily acts to **increase** enzymatic secretion * Little effect on **H2O/HCO3-** secretions (aqeuos)
55
Intestinal Phase and Pancrease Secretions: * provides the [] stimulus for secretion * Primary Agents * [] - form S-cells * [] - from I-cells * [] via Vagovagal reflexes
* provides the **most** stimulus for secretion * Primary Agents * **Secretin** - form S-cells * **Cholecystokinin** - from I-cells * **Acetylchoine** via Vagovagal reflexes
56
Intestinal Phase and Pancreatic Secretion: Mechanism * pH \< 4.5 * Stimulates []-cells of duodenal mucosa to produce secretin * Secretin stimulates [] of aqueous component * Fats/Proteins/H+ * stimulate []-cells ofo duodenum to produce CCK * CKK increases the [] component of secretion * Acetylcholine * Acts via [] (Vagovagal) of H+, fatty acids, peptides, amino acids. * Increases [] component of secretion
* pH \< 4.5 * Stimulates **S**-cells of duodenal mucosa to produce secretin * Secretin stimulates release of **aqueous** component * Fats/Proteins/H+ * stimulate **I**-cells ofo duodenum to produce CCK * CKK increases the **enzymatic** component of secretion * Acetylcholine * Acts via **chemoreception** (Vagovagal) of H+, fatty acids, peptides, amino acids. * Increases **enzymatic** component of secretion
57
* **Choleresis** - parenchymal secretion of lipid/bile against the concentration gradient? * **Choleretic** - a substance that increases Bile Flow
58
Bile Salts/Acid * Synthesis is mediated by the cytoplasmic enzyme [] * Derivative of [] * Hydrophilic and Hydrophobic = []
* Synthesis is mediated by the cytoplasmic enzyme **7à-Hydroxylase** * Derivative of **cholesterol** * Hydrophilic and Hydrophobic = **amphipathic**
59
* [] Bile Acids are formed by the Liver, from scratch * the 2 we know: [] Acid and [] Acid * [] Bile Acids are formed by [] bacteria from teh primary Bile Acids * The 2 we know: [] Acid and [] Acid
* **Primary** Bile Acids are formed by the Liver, from scratch * the 2 we know: **Cholic** Acid and **Chenodeoxycholic** Acid * **Secondary** Bile Acids are formed by **GI** bacteria from the primary Bile Acids * The 2 we know: **Deoxycholic** Acid and **Lithocholic** Acid
60
Lithocholic Acid * Only Bile Acid that can be []by the liver * This will not be [] * The predominant Bile Acid in []
* Only Bile Acid that can be **sulfonated** by the liver * This will not be **reabsorbed** * The predominant Bile Acid in **feces**
61
T/F The primary bile acids are not reabsorbed in the intestines and are predominately found in feces.
FALSE This is describing lithocholic acid...which is a secondary bile acid.
62
Liver Ductal Cells * Secrete [] and [] which are an ultrafiltrate of plasma * Stimulated by [] to produce HCO3-
* Secrete **H2O** and **electrolytes** which are an ultrafiltrate of plasma * Stimulated by **Secretin** to produce HCO3-
63
Regulation of Bile secretion - Enterohepatic Circulation: 1. Accounts for [] of Bile salt secretion 2. [] reabsorption from intestine 3. [] reabsorption from [] ileum 4. entire bile salt pool may be [] several times/meal
1. Accounts for **most** of Bile salt secretion 2. **Passive** reabsorption from intestine 3. **Active** reabsorption from **terminal** ileum 4. entire bile salt pool may be **recirculated** several times/meal
64
Secretion of Bile (from liver) is increased by: 1. [] stimulation ([] phase) 2. [] hormone 3. Increasd liver [] flow
1. **Vagal** stimulation (**Cephalic** phase) 2. **Secretin** hormone 3. Increasd liver **blood** flow
65
Enterohepatic Regulation of Bile Production * Senses Primary/secondary bile acids return from enterohepatic circulation * Centered on regulating the [] enzyme via the [] [] [] * [] of Nuclear Receptor FXr -\>[] gene expression of 7à-Hydroxylase -\> * decreased production fo newly []primary bile acids --\> [] of existing primary and secondary bile acids.
* Senses Primary/secondary bile acids return from enterohepatic circulation * Centered on regulating the **7à-Hydroxylase** enzyme via the **Nuclear Receptor FXR** * **Activation** of Nuclear Receptor FXr -\> **Decreased** gene expression of 7à-Hydroxylase -\> * decreased production of newly **synthesized** primary bile acids --\> **secretion** of existing primary and secondary bile acids.
66
Intestinal Secretions * Mucus * released by [] cells through [] & exocytosis processes * Increased secretion by: * [] NS * [] hormone * [] Reflexes (Mechano/Chemo)
* Mucus * released by **goblet** cells through **exfoliation** & exocytosis processes * Increased secretion by: * **Parasympathetic** NS * **Secretin** hormone * **Tactile** Reflexes (Mechano/Chemo)
67
Intestinal Secretions: * Electrolytes * serves as vehicle for [] * Secretion [] during digestive phase
* serves as vehicle for **reabsorption** * Secretion **increases** during digestive phase
68
Intestinal Secretions: * Hormones: * [] - stimulates electrolyte secretion * [] - stimulate enzymatic secretion
* Hormones: * **Secretin** - stimulates electrolyte secretion * **CCK** - stimulate enzymatic secretion
69
Intestinal Secretions: * Extracellular Enzymes * [] (enterokinase) * converts trypsinogen (comes from []) into [] * []-amylase * Brush Border * [] step in digestion * Tons of enzymes: peptidases, lipase, sucrase, maltase, lactase
* Extracellular Enzymes * **Enteropeptidase** (enterokinase) * converts trypsinogen (comes from **pancrease**) into **trypsin** * **alpha**-amylase * Brush Border * **Last** step in digestion * Tons of enzymes: peptidases, lipase, sucrase, maltase, lactase
70
Secretory Diarrheal Dysfunction: * Typically caused by [] bacteria * Permanetly [] adenyl cyclase elevating crypt levles of [] * Activates brush border [] channel and deactivates [] on basolateral side * Na+ and Cl- secrete, taking [] with them. * Can poop out [] L/day * Best treatment - []
* Typically caused by **Cholera** bacteria * Permanetly **activates** adenyl cyclase elevating crypt levles of **cAMP** * Activates brush border **Cl-** channel and deactivates **Na+** pump on basolateral side * Na+ and Cl- secrete, taking **water** with them * Can poop out **20** L/day * Best treatment - **rehydration**
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Colonic Secretions: * Mucus high in [] and [] and comes from []cells * Functions to main [], [], and bind [] together * Regulated * Local [] reflex * Parasympathetic NS [] secretion (form pelvic nerve) * Sympathethetic NS [] secretion (from pelvic nerve)
* Mucus high in **K+ and HCO3-** and comes from **goblet** cells * Functions to maintain **neutrality**, **lubricate**, and bind **feces** together * Regulated * Local **intrinsic** reflex * Parasympathetic NS **increase** secretion (form pelvic nerve) * Sympathethetic NS decrease secretion (from pelvic nerve)

Dental Physio (36 decks)

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