GI: Salivary Glands

Question 1

What are the three salivary glands? Minor?

Answer 1

Major: parotid, sublingual, submandibular
Minor: Labial, Palatine, Buccal, Lingual (von Ebner’s gland) Sublingual mucosae

Question 2

Which major salivary glands have a single duct? Multiple ducts?

Answer 2

Single: Parotid and submandibular
Multiple: Sublingual

Question 3

The Parotid (___) duct empties opposite the upper ___ molar.

Answer 3

Stensen’s; second

Question 4

The parotid is a ___ gland that produces a ___ secretion. It is also a major source of ___.

Answer 4

serous; watery; amylase

Question 5

What duct opens beneath the base of the tongue?

Answer 5

Submandibular (Wharton’s) duct

Question 6

The submandibular gland produces ___ secretions that include what?

Answer 6

Mixed (serous/mucous)

water/electrolytes and mucin

Question 7

The ___ gland’s (___) duct branches with several openings into the anterior floor. It makes mostly ___ secretions.

Answer 7

Sublingual; Rivinus’s; mucous

Question 8

T/F. The parotid and submandibular glands are inactive at rest and the sublingual gland is active at rest.

Answer 8

False, The parotid and SUBLINGUAL glands are inactive at rest and the SUBMANDIBULAR gland is active at rest.

Question 9

T/F. The minor salivary glands secrete mostly mucous except von Ebner’s glands.

Answer 9

True.

Question 10

Minor salivary glands make up ___-___% of the total (___ml) saliva.

Answer 10

5-10%; 750ml

Question 11

Which glands, major or minor, harbor lymphocytes?

Answer 11

minor

Question 12

Von Ebner’s glands are involved with ___ by rinsing the ducts of ___ and ___ papillae.

Answer 12

rinsing; circumvallate; foliate

Question 13

Von Ebner’s glands secrete lingual ___ to initiate fatty acid digestion that continues into the stomach. How are they these enzymes active in the stomach?

Answer 13

lipases

they are acid resistance proteins and therefore, can remain active in low pH and continue to breakdown fats

Question 14

Describe the structures that saliva passes as it exits the salivon.

Answer 14

1. acinus (acinar and myoepithelial cells)
2. intercalated duct
3. striated duct
4. excretory duct

Question 15

Describe the composition of saliva.

Answer 15

water
inorganic salts
organic components

Question 16

What percentage of saliva is made up of water?

Answer 16

99.5%

Question 17

What organic components originate from acinar cells?

Answer 17

amylase (from parotid gland - break down starch)
lipase
mucoproteins (mucins)
Proline- and Tyrosine-rich proteins (bind Ca++ and prevent it from precipitating out in saliva)

Question 18

What organic components are not made by acinar cells?

Answer 18

lysozymes (break down bugs)
immunoglobulin
growth factors (support tissues in mouth and GI tract)
regulatory proteins (NGF)

Question 19

Saliva’s pH is highly buffered from ___ to ___ to avoid tooth damage.

Answer 19

6.4 - 7.4

Question 20

Describe the salivary fluid secretion mechanism that accounts for most salivary secretions.

Answer 20

1. Na+/K+ ATPase Pump brings more Na+ outside than inside
2. Na+ passes inside via transporter b/c of concentration gradient. Transporter also brings Cl- and K+. This concentrates Cl- inside the cytoplasm.
3. When the cell is stimulated, Ca++ gated Cl- channels open releasing Cl- into the lumen.
4. Na+ in interstitium drawn between tight junctions between ducts and H2O follows.

Question 21

Describe the alternative method that uses bicarb to cause salivary fluid secretion.

Answer 21

1. CO2 and H2O is converted by carbonic anhydrase to form bicarb (HCO3-).
2. HCO3- collects within the cell and transporter uses concentration gradient to put HCO3- out and bring Cl- in.
3. When the cell is activated, Ca++ gated Cl- channels open sending intracellular Cl- out of the cell.
4. Na+ passes between cells thru tight junctions and H2O follows.

Question 22

Describe the alternative salivary fluid secretion method that concentrates bicarb in the lumen.

Answer 22

HCO3- draws Na+ across not Cl-

1. CO2 and H2O are converted to HCO3- by carbonic anhydrase. HCO3- accumulates within the cell.
2. Ca++ gated BICARB channels puts HCO3- into the lumen.
3. Na+ passes between cells thru tight junctions and H2O follows to make serous secretion

Question 23

1. In salivary fluid secretion, intracellular Na+ is kept ___ and intracellular K+ is kept ___.
2. Intracellular Cl- is ___.
3. In unstimulated cells, ___ levels are low and Ca2+ activated K+ and Cl- channels are ___.
4. Upon stimulation, ___ opens Cl- and K+ channels.
5. ___ leaks through tight junctions to follow ___.

Answer 23

1. low; high
2. high
3. Ca2+; closed
4. Ca2+
5. Na+; Cl-

Question 24

As saliva flows down the duct, ___ cells modify the saliva by removing Na+, Cl-, and HCO3- so that the saliva becomes ___ to plasma. In order for this to happen the saliva must be moving ___. If the gland is hyperstimulated, the saliva will be ___.

Answer 24

ductal; hypotonic; slowly; isotonic

Question 25

T/F. The tight junctions of ductal cells are permeable to H2O with a Na+ concentration gradient, however, acini are not permeable to H2O.

Answer 25

False, The tight junctions of ACINI cells are permeable to H2O with a Na+ concentration gradient, however, DUCTAL are not permeable to H2O.

Question 26

In ductal cells, the number of ___ are distributed in a polarized manner across the cell. These cells reabsorb ___ and ___ but not ___.

Answer 26

transporters; Na+; Cl-; H2O

Question 27

Describe how ductal cells work.

Answer 27

1. ATPase pumps Na+ out of the cell into the interstitium to create a concentration gradient. 2. A transporter allows Na+ to pass into the cell from the lumen. 3. Cl- is brought out of the saliva into the cell then into the interstitium. 4. HCO3- is removed from the cell and passed in the lumen

Question 28

T/F. The electrolyte composition is unaffected by flow rate in primary (acini) salivary secretions, however secondary (ductal) cells' electrolyte composition is strongly affected by flow rate.

Answer 28

True.

Question 29

In secondary (ductal) modifications, low rate = high [___] and high rate = high [___].

Answer 29

K; Na

Question 30

What is the most abundant protein in saliva? Which glands produce it? What is its composition and function?

Answer 30

mucin sublingual and submandibular glands carbohydrate-rich protein salivary visocity

Question 31

___ is predominately produced by the parotid glands and is packed in ___ granules. It is involved in the initiation of ___ breakdown.

Answer 31

Amylase; zymogen; starch

Question 32

Match: 1. Digestive protein 2. Immune-associated protein 3. Calcium binding protein 4. Growth factors A. Lactoferrin (binds iron to keep from bac - prevents replication) B. PRP, TRP (statherin) cystatins, histatins (promote mineralization of teeth) C. Lingual lipase from von Ebner's gland (fat breakdown) D. EGF, NGF (stimulates gastric and nerve growth) E. Immunoglobulins (sIgA) F. Muramidase (lyse muramic acid in the cell wall of bac)

Answer 32

1 - C 2 - A, E, F 3 - B 4 - D

Question 33

How are protein secreted?

Answer 33

proteins are packed into vesicles that fuse with the plasma membrane and release its contents via exocytosis

Question 34

How is salivation controlled?

Answer 34

autonomic nervous system

Question 35

Cranial nerve VII (psymp) supplies what structures?

Answer 35

1. glands of palate and nose 2. sublingual 3. submandibular

Question 36

What structures are supplied by CN IX (psymp)?

Answer 36

1. Parotid | 2. lingual

Question 37

What structures are innervated by the sympathetic system?

Answer 37

all of the salivary glands and blood vessels

Question 38

___ cells have contractile properties. When contracted, it'll squeeze the acini and allow ___ to get into the ductal region.

Answer 38

Myoepithelial; H2O

Question 39

What neurotransmitters are involved in salivation?

Answer 39

1. parasymp - ACh 2. symp - NE 3. others - substance P and vasoactive intestinal peptide (VIP) - found in sensory neurons involved in salivation 4. others - neuropeptide Y (NPY) and calcitonin gene related peptide - influence motor neurons

Question 40

What areas of the brain are involved in salivation?

Answer 40

1. superior solitary nucleus - impulses from the brain go down thru CN VII 2. Inferior solitary nucleus - impulses go thru CN IX

Question 41

The reflex loop is initiated by mechanoreceptors in the ___ ___ and ___. Afferent impulses signal what nerves? Where do they synapse?

Answer 41

periodontal ligament; tastebuds Afferent - trigeminal, facial, glossopharyngeal Synapse - trigeminal, solitary nucleus -if superior SN impulse travels down CN VII -if inferior SN impulse travels down CN IX

Question 42

Psymp stimulation releases ___ onto the acinar cells and results in ___ plasma-like secretion.

Answer 42

ACh; watery

Question 43

ACh binds a ___ receptor, which is a GPCR, to activate PLC. PLC leads to ___ activation, which binds to the ___ ___ and opens Ca2+ channels. What does the Ca2+ go on to do?

Answer 43

muscurinic; IP3; endoplasmic reticulum Ca2+ activates Ca2+ gated Cl- channels causing Cl- to leave the cell and enter the lumen. Na+ follows Cl- and H2O follows Na+

Question 44

T/F. Psymp secretion greatly enhances protein secretion (via beta adrenergic receptors).

Answer 44

False, SYMP secretion greatly enhances protein secretion (via beta adrenergic receptors).

Question 45

___ secretion is by PKA mediated exocytosis.

Answer 45

Protein

Question 46

T/F. Muscarinic or alpha adreneergic receptor activation causes intracellular release of Ca2+, which goes to activate K+ and Cl- channels. This causes an increase in luminal Cl- concentration and intercellular Na+ concentration. Water will follow.

Answer 46

True.

Question 47

___ is primarily used ( with some effect of NE via ___-adrenergic receptors) to open ___ sensitive Cl- and K+ channels. This will increase flow rate and lower ductal modifications.

Answer 47

Acetylcholine; alpha; Ca2+

Question 48

___ stimulated cells produce protein rich saliva through ___ mediated exocytosis via the ___-adrenergic receptor.

Answer 48

NE; PKA; beta

Question 49

What can saliva detect as a diagnostic fluid?

Answer 49

1. infection 2. endocrine disorders 3. cardiovascular markers 4. cancer

Question 50

What type of conditions can occur when saliva goes bad?

Answer 50

1. halatosis 2. dry mouth and tongue thickness (bulbus) with deep fissures 3. demineralization of teeth due to lack of Ca2+ binding proteins 4. ducts attacked by infection leading to lack of secretion and glandular swelling

Question 51

Which of the following is true about Xerostomia? 1. it is prevalent in the aging 2. it is caused by drug/treatment side effects 3. it is caused by autoimmune disorders 4. 1 and 2 are true 5. all of the above are true.

Answer 51

5

Question 52

What type of treatment is available for patients suffering from xerostomia?

Answer 52

muscarinic (ACh) receptors (pilocarpine) | symptom management