Secretions - Lopez

Question 1

What is the origin of the salivary gland?

Blood supplied to it is from where?

Answer 1

Ectodermal

External carotid a.

Question 2

What is responsible for ejecting saliva into the mouth?

Answer 2

Myoepithelial cells

Question 3

In the intercalated duct, what is saliva compared to plasma?

Answer 3

Ionic composition

Question 4

What is the striated duct lined by?

How does it modify saliva?

Answer 4

Columnar epithelial cells

Makes it hypotonic

Question 5

What is saliva composed of?

Answer 5

H20
Alpha-amylase
Lingual lipase
Kallikrein

Question 6

Describe K, Na, HCO3, Cl [ ]s compared to plasma

Answer 6

HIGH K, HCO3

low NaCl

Question 7

What does Kallikrein do?

Answer 7

Makes bradykinin (vasodilator)

Question 8

Is there more absorption or secretion of solute?

Answer 8

More absorption (NaCl)

Question 9

Name the exchangers (3) in the salivary ductal cell

Answer 9

Na/H
Cl/HCO3
H/K

All on apical membrane

Question 10

What does the CFTR channel secrete or absorb?

How is it activated?

Answer 10

SECRETES HCO3 and Cl-

By cAMP

Question 11

What is the result in patients with deficient CFTR gene?

Answer 11

Ca, Na, protein INCREASED

Question 12

What is super special about ductal cells?

Answer 12

ductal cells are IMPERMEABLE to water

Question 13

Where do PS presynaptic nerves originate?

What do postsynaptic fibers innervate?

Answer 13

CN 7 and 9

Individual glands

Question 14

Where do Symp preganglionic nerves originate?

Where do the postganglionic extend to?

Answer 14

Cervical ganglion

Periarterial space glands

Question 15

What does CN 7 innervate?

CN 9?

(Both PS pathways)

Answer 15

Submandibular and sublingual glands

Parotid gland

Question 16

What nt does PS salivary secretion use?

What receptor?

What 2nd messenger?

Answer 16

ACh

MAChR

IP3 and Ca2+

Question 17

What nt does Symp pathway use for salivary secretion?

What spinal levels?

What receptor and 2nd messenger?

Answer 17

NE

T1-T3

Beta-andrenergics

cAMP

Question 18

How does vasopressin and aldosterone modify saliva?

Answer 18

Dec. [Na] and INC [K]

By inserting channels in membrane (reabsorbs sodium)

Question 19

What branch of the ANS increases salivary secretion?

Answer 19

BOTH

Question 20

What are the main components of gastric juice?

Answer 20

HCl
Pepsinogen
Mucus
Intrinsic Factor
H2O

Question 21

What is intrinsic factor required for?

Where?

Answer 21

Absorption of Vit B12

Ileum

Question 22

Where is the oxyntic gland located?

What does it secrete?

Answer 22

Proximal 80% of stomach (body and fundus)

Acid

Question 23

Where is the pyloric gland located?

Function?

Answer 23

Distal 20% of stomach (antrum)

Release Gastrin

Question 24

Where are parietal cells located?

What do they secrete?

Answer 24

Oxyntic glands

HCl, Intrinsic factor

Question 25

Where are G cells located?

Answer 25

Pyloric gland

Question 26

In the gastric parietal cell, what exchanger is located on the luminal side?

Answer 26

H+/K+ H+ is going into lumen (secreted) as Cl- follows H+

Question 27

What inhibits the H+ ion exchanger?

Answer 27

Omeprazole

Question 28

What exchanger is located on the basolateral side?

Answer 28

HCO3-/Cl- exchanger Cl- going back INTO the cell

Question 29

What is absorbed via the parietal cell?

Answer 29

HCO3- absorbed into blood

Question 30

What releases histamine? What else stimulates histamine release? What does histamine do?

Answer 30

ECL cells ACh and Gastrin Stimulates HCl secretion

Question 31

Where does histamine bind? What blocks the receptors? What does it act through?

Answer 31

H2 receptors Cimetidine cAMP

Question 32

What releases ACh? What does it stimulate?

Answer 32

Vagus n. HCl secretion

Question 33

Where does ACh bind? What blocks the binding? What 2nd messenger does it use?

Answer 33

M3 on parietal cells Atropine IP3/Ca2+

Question 34

Where does Gastrin bind CCK? What 2nd messenger does it work through? Does Atropine block this pathway?

Answer 34

CCK B receptors on parietal cells IP3/Ca2+ NO

Question 35

What releases somatostatin? What does it do? Where does it bind?

Answer 35

D cells in antrum inhibits HCl SSTR2 on parietal cells

Question 36

What effects does somatostatin have?

Answer 36

Direct effect - inhibits adenylate cycle -> inhibit H+ Indirect effect - inhibits histamine and Gastrin

Question 37

What has potentiation effects?

Answer 37

Histamine on ACh and Gastrin ACh on histamine and Gastrin

Question 38

What do PGs do in gastric parietal cells?

Answer 38

Inhibits cAMP (Gi)

Question 39

What nt do G cells use when vagally stimulated?

Answer 39

GRP

Question 40

What stimulates the cephalic phase?

Answer 40

Smelling, tasting, chewing, swallowing

Question 41

What is the MOA for the cephalic phase?

Answer 41

Vagus n. -> parietal cell using ACh Vagus n. -> Gastrin -> parietal cell using GRP

Question 42

What stimulates the gastric phase?

Answer 42

Distention of stomach, breakdown proteins, a.a., small peptides

Question 43

What are the MOA for the gastric phase?

Answer 43

2 Vagal reactions Distention of antrum A.a. And small peptides

Question 44

What foreign substance can stimulate gastric HCl secretion?

Answer 44

Coffee (incl. decaf)

Question 45

What stimulates the intestinal phase?

Answer 45

``` Distention of s.i. Digested proteins (a.a.) via direct effect ```

Question 46

Gastric juice is what kind of solution? low secretion rates what is high? High secretion rates?

Answer 46

Isotonic NaCl HCl

Question 47

What is the most important stimulus for pepsinogen secretion?

Answer 47

Vagus nerve stimulation

Question 48

When is pepsin irreversibly inactivated?

Answer 48

pH > 7-8

Question 49

What leads to pernicious anemia?

Answer 49

Failure to secrete intrinsic factor | Atrophic gastritis

Question 50

What damages the gastric mucosa?

Answer 50

``` acid Pepsin NSAIDs H. Pylori Alcohol Bile Aspirin ```

Question 51

How do gastric ulcers primarily form? What is the major cause? Via what mechanism?

Answer 51

Mucosal barrier defective H. Pylori Urease allows bacteria to colonize the gastric mucosa, converts urea to NH3

Question 52

How do duodenal ulcers form? Cause?

Answer 52

H+ secretory rates higher than normal (most common) indirectly H.pylori inhibits somatostatin

Question 53

What are the 2 main components of the exocrine pancreas?

Answer 53

Aqueous solution, has HCO3- | Enzymatic secretion

Question 54

What secretes the HCO3-?

Answer 54

Ductal and centroacinar cells

Question 55

Where are Symp post-gang nerves from?

Answer 55

Celiac and Superior Mesenteric plexuses

Question 56

PS nervous system innervation from where? Where do preganglionics synapse? Postganglionics?

Answer 56

Vagus n. ENS On exocrine pancreas

Question 57

In the exocrine pancreas what is inhibitory? Excitatory?

Answer 57

Symp PS

Question 58

Where are pancreatic proteases activated?

Answer 58

Lumen of duodenum

Question 59

What exchanger is present on the luminal side of the pancreatic ductal cell?

Answer 59

HCO3-/Cl- HCO3- secreted into pancreatic juice

Question 60

What exchanger is present on the basolateral side of pancreatic ductal cell?

Answer 60

H+/Na+ | H+ into the blood, so it becomes ACIDIC

Question 61

At high flow rate is bicarbonate high or low in pancreatic juice?

Answer 61

HIGH

Question 62

Which phase of pancreatic secretions accounts for the majority of secretion? What does this phase have that the others don't?

Answer 62

Intestinal (80%) Has enzymatic and aqueous secretions

Question 63

Whic salivary gland is the largest? What enzyme does it have a lot of?

Answer 63

Parotid gland Amylase