Physiology of Salivary Gland Secretion

Question 1

Gland secretion involves two integrated processes including:

Answer 1

1) Production of fluid (water and electrolytes)

2) Secretion of proteins (mainly by exocytosis)

Question 2

_____ stimulation leads to the production of saliva at a rather high flow rate but with ___ organic content

Answer 2

Parasympathetic, high

Question 3

______ stimulation leads to a relatively smaller increase, but more of a ____ nature

Answer 3

Sympathetic, viscous

Question 4

Neurotransmitters evoke salivary gland secretion by binding to specific receptors on _____ surface of ____ cells

Answer 4

basolateral, acinar

Question 5

Neurotransmitters trigger production of specific ___ messages

Answer 5

intracellular

Question 6

Intracellular messages trigger production of ____ secretion and exocytosis of _____

Answer 6

fluid/ion, proteins

Question 7

Sympathetic neurotransmitter

Answer 7

Norepinephrine (and epinephrine)

Question 8

Norepinephrine and epinephrine bind to ____ receptors

Answer 8

adrenergic

Question 9

Sympathetic receptors are

Answer 9

alpha adrenergic, and beta adrenergic

Question 10

Parasympathetic neurotransmitter

Answer 10

Acetylcholine

Question 11

Acetylcholine acts on ____ receptors

Answer 11

muscarinic

Question 12

Parasympathetic receptor is

Answer 12

muscarinic

Question 13

Majority of protein synthesized and secreted by ____ cells

Answer 13

acinar

Question 14

Serous and mucinous acini secrete ____ protein mixtures

Answer 14

different

Question 15

Acini secrete ____ mix of inorganic ions

Answer 15

isotonic

Question 16

Ducts reabsorb ___ , ____ and release ____

Answer 16

• Na+, Cl-,

- K+

Question 17

Final saliva is a ____ solution

Answer 17

hypotonic

Question 18

Unstimulated saliva flow rate is

Answer 18

.1 ml/min

Question 19

Stimulated saliva flow rate is

Answer 19

1.1-3 ml/min

Question 20

____ gland produce most volume in stimulated saliva

Answer 20

Parotid

Question 21

_____ glands produce most volume in unstimulated saliva

Answer 21

Submandibular/sublingual

Question 22

Salivary fluid is formed by a two stage process, first being:

Answer 22

Formed as a nearly isotonic plasma-like secretion in acinar lumen.

Question 23

Salivary fluid is formed by a two stage process, second being:

Answer 23

modified in ducts by removal of Na+, Cl- and addition of K+ and HCO3-.
-No further secretion or absorption of water to produce a hypotonic solution.

Question 24

First stage of fluid secretion is dependent on

Answer 24

Cl- and HCO3-

Question 25

Fluid secretion is the result of concerted action of four membrane transport systems

Answer 25

1. loop diuretic (eg furosemide, bumetanidine) sensitive Na+/K+/Cl- ion cotransporter in acinar basolateral membrane 2. Basolateral Ca2+ activated K+ channel 3. Basolateral Na/K ATPase 4. Apical Ca2+ activated Cl channel

Question 26

In resting state, ___ + ___ concentrated in acinar above electrochemical equilibrium

Answer 26

K+, Cl-

Question 27

____ by Na+/K+ ATPase

Answer 27

K+

Question 28

____ by Na+/K+/Cl- contransporter

Answer 28

Cl-

Question 29

Cl- ion secretion by Na+/K+/Cl- contransporter when stimulate by alpha adrenergic or cholinergic secretagogue leads to:

Answer 29

- Intracellular Ca2+ increase - Opens basolateral K+ channel, apical Cl- channel - K+ exits cell basolaterally - Cl- exits cell into lumen - Net negative charge in lumen - Na+ follows Cl- by leaking from interstatium - Creates NaCl osmotic gradient - Causes transepithelial movement of water into lumen

Question 30

CO2 enters cell and is converted to HCO3- and H+ by _______

Answer 30

Carbonic anhydrase

Question 31

Cl-/HCO3- basolateral exchange increases ____ concentration

Answer 31

Cl-

Question 32

Cl- leaves the cell by _____ activated channel

Answer 32

Ca2+

Question 33

pH maintained by

Answer 33

Na+/H+, Na+/K+ exchangers, and K+ channel

Question 34

Carbonic anhydrase action _______ cytoplasm

Answer 34

acidifies

Question 35

Cl- channel allows ____ release to lumen, which facilitates water movement

Answer 35

HCO3-

Question 36

pH of cytoplasm maintained by further ______ transport

Answer 36

ion

Question 37

Electroneutral ameloride-sensitive Na+/H+ exchanger exports protons driven by _____ gradient

Answer 37

Na+

Question 38

NA+/H+ exchange further stimulated by

Answer 38

muscarinic, alpha-adrenergic agonist

Question 39

Na+/K+ ATPase reduces ___ level in the cell

Answer 39

Na+

Question 40

K+ channel opens on stimulation to maintain

Answer 40

K+

Question 41

G proteins associated with membrane normally present as ____ GDP-bound heterotrimer GDP-G(alpha-beta-gamma)

Answer 41

inactive

Question 42

Binding of _____ to alpha-adrenergic or muscarinic receptor leads to receptor cytoplasmic domain interaction with particular GDP-G(abg)

Answer 42

agonist

Question 43

Stimulates exchange of GTP for GDP and release of GTP bound...

Answer 43

G alpha subunit

Question 44

_______ is active, and can associate with other | enzymes. (e.g. phospholipase C)

Answer 44

GTP-Galpha

Question 45

Phospholipase C converts PIP2 to

Answer 45

IP3 and DAG

Question 46

IP3 trigger release of ___ from ER to cytoplasm

Answer 46

Ca2+

Question 47

DAG activates ...

Answer 47

protein kinase C (involved in various cellular responses like amylase secretion)

Question 48

Binding of B-adrenergic agonist to its receptor leads to formation of distinct _____ complex. Then interacts with adenylate cyclase.

Answer 48

GTP-G alpha

Question 49

GTP-Galpha convert ATP to cAMP which activates cAMP dependent protein kinase and other enzymes which ultimately promotes _____

Answer 49

exocytosis

Question 50

____ pathway is the predominant pathway regulating exocytosis

Answer 50

cAMP

Question 51

___ increase also promotes exocytosis

Answer 51

Ca2+

Question 52

T or F: Parasympathetic pathways do not solely stimulate fluid secretion.

Answer 52

T

Question 53

T or F: Sympathetic pathways do not solely stimulate protein exocytosis

Answer 53

T

Question 54

Ductal modification of saliva includes net reabsorption of

Answer 54

Na and Cl

Question 55

Ductal modification produces a _____ solution

Answer 55

hypotonic

Question 56

At high flow rates

Answer 56

NA+, Cl- rises and K+ falls

Question 57

Electrolyte secretion/reabsorption regulates by

Answer 57

ANS and mineralocorticoids

Question 58

____ more important for regulating electrolyte transport in ducts compared to acini

Answer 58

Sympathetic