Histology of Salivary Glands (Quiz 1)

Primary functions of saliva:

Protection

buffer __ of the oral cavity

________ formation

maintenance of tooth ______

_____________ action

_______ repair

digestion begins in oral cavity

taste

pH

pellicle

integrity

antimicrobial

tissue

What are the three pairs of major salivary glands?

Parotid, submandibular, and sublingual glands.

Which is the largest major salivary gland?

The parotid gland.

The parotid gland is associated with ______ nerve

facial

The innervation pathway of the parotid gland:

______________ (parasympathetic or sympathetic) nerves travel with CN __ (Glossopharyngeal Nerve).

___________ (preganglionic or postganglionic) parasympathetic nerves will synapse in the ____ ganglion

___________ (preganglionic or postganglionic) parasympathetic nerves will synapse in the _______________ nerve.

Parasympathetic

IX

otic

auriculotemporal

Where are the submandibular glands located?

In the posterior floor of the mouth.

Which is the second largest major salivary gland?

submandibular glands

How do the ducts of the submandibular glands open into the mouth?

Via the sublingual caruncles (2)

Innervation pathway for the submandibular glands:

_______________ (preganglionic or postganglionic) ______________ (parasympathetic or sympathetic) nerves run with facial nerve ___, and the branch that comes off of the facial nerve, which is called the ______ tympani, will join the _______ nerve, then synapse in the submandibular ganglion.

_______________ (preganglionic or postganglionic) will go to the submandibular gland

preganglionic

parasympathetic

VII

chorda

lingual

postganglionic

What is unique about the sublingual glands?

They are the smallest of the major salivary glands and open into the floor of the mouth via many small ducts, and at the sublingual caruncle

Innervation of the sublingual glands is exactly the same as the _____________ glands, both receiving parasympathetic secretomotor fibers from the facial nerve (via the chorda tympani)

Submandibular + Sublingual = CN VII (chorda tympani → lingual nerve → submandibular ganglion)

submandibular

How many minor salivary glands are there approximately?

600-1000 in number.

Minor salivary glands are present throughout the oral muscosa, except for the _________ palate and the ________

anterior

gingiva

Most of the minor salivary glands are _______ (mucous or serous)

EXCEPT: ____ ______ glands, which are found on the ________, are pure _______ (mucous or serous) glands

COMMONLY ASKED QUESTION

mucous

Von Ebnar's

tongue

serous

Development of Salivary Glands:

- As the oral cavity is first developing, it is lined by a layer of ____ epithelium sitting on a basement membrane, and on the other side of that membrane is surrounding ______________

- As the salivary glands develop, they remain connected to the surface epithelium by ______ or epithelial cells

- mesenchymal cells will _________ around the gland

- Then they go through __________ ____________

- Theres no ______ when these cells first develop

oral

ectomesnchyme

cords

condense

branching morphogenesis

lumen

Development of Salivary Glands:

- Eventually, the lumen will appear first in the _____ part of these cord cells and the branches, then in the _________ cord, and then in the _______ of the main cord

distal

proximal

central

Development of Salivary Glands:

You end up with two layers of cells:

• ______ (inner or outer) layer differentiates into secretory cells

• ______ (inner or outer) layer differentiates into myoepithelial cells, capsule and septa

inner

outer

What do secretory cells produce?

saliva

Histology of salivary glands

• _________ end pieces, or acini (singular: acinus*)

• cluster of secretory cells

• resemble clusters of grapes, each “grape” made up of a group of 8-10 cells, which secrete _________ _______ into a common lumen

secretory

primary saliva

The composition of serous saliva is fluid rich in _______ and ____________

proteins

glycoproteins

Serous acini are more _________ in shape, with __________-shaped cells and _________ located nuclei

- secretory granules (sacs that store and transport) located ________/at the apex of each cell, and contain ______________

• The serous cell contains a lot of rER, Golgi, mitochondria, lysosomes, etc., located in _____ part of cell

Spherical

pyramid

basally

apically

macromolecules

basal

What is the function of mucins in saliva?

They lubricate and form a surface barrier, binding and aggregating microorganisms.

serous cells

• have short _________

• lateral _______________ (folding of the lateral walls)

• basal membrane ________, which allows for the movement of fluid by increasing the surface area

• cells held together by _________ complexes, ____________, ___ junctions

• intercellular _________ are finger-like projections of lumen

between adjacent cells – increase lumen surface area

microvilli

interdigitations

infolding

junctional

hemidesmosomes

gap

canaliculi

- folded membrane at the bottom of cell, vesicles at the top, nucleus located basally,

Mucous cells produce, ______, which are rich in ______________.

Mucins

glycoproteins

mucous cells

• secretory end pieces are ________

• sometimes you'll have pure serous acini, sometimes pure mucous acini

• other times, you can have acini with both serous and mucous cells

• when this happens, the mucous cells are found in the _______, and the serous cells are found in the __________

tubular

center

periphery

mucous cells

• apical part of cell contains large quantities of ______

• nucleus, rER compressed _______ basal membrane

• in routine H&E, cells appear _______; special stains reveal mucous content

• cells joined by _________ complexes

• cells lack intercellular _________

mucins

against

empty

junctional

canaliculi

myoepithelial cells

• ___________ – similar to ________ muscle, but derived from __________ rather than mesenchyme

• surround _____ and intercalated ducts

• located between basal lamina and secretory cells or ducts – attach by _____________

• have multiple processes containing actin and myosin, with caveolae

smooth

contractile

epithelium

acini

hemidesmosomes

myoepithelial cells roles

• support secretory cells – help expel ________ saliva by contracting

• help maintain duct patency (hold them open)

• provide ______ to acinar cells

• might have tumor suppressor activity

• proteinase inhibitors

• anti-angiogenesis factors

primary

signals

Intercalated ducts

• receive _______ saliva from secretory cells

• lined by simple _______/cuboidal epithelium

• centrally located nucleus

• surrounded by ___________ cells

• have typical organelles, connected by junctional complexes, desmosomes and gap junctions

• the ducts add ________ and ________ to the saliva (antimicrobial proteins)

primary

squamous

myoepithelial

lysozyme

lactoferrin

striated ducts

• receive ________ saliva from intercalated ducts

• form major portion of duct system

• cells _________ in shape

• __________ located nucleus, acidophilic cytoplasm

• basal striations (highly folded) = mitochondria + membrane infoldings

• surrounded by basal lamina and _______ plexus

• contain secretory granules, lysosomes, peroxisomes, glycogen

• tight junctions, junctional complexes; no gap

- the composition of _________ is changed in the striated ducts

primary

columnar

centrally

capillary

saliva

What is the largest duct called?

excretory duct

excretory ducts

• _______ ducts lead to excretory ducts

• located in CT septa between lobules

• pseudostratified to stratified epithelium, attached to

basal lamina by hemidesmosomes

• ____ cells with long stiff microvilli and apical vesicles - might be receptor cells: associated with nerve endings

• lymphocytes, macrophages, dendritic cells - found in _____ of duct epithelium

striated

tuft

base

Surrounding the entire salivary gland is a _______. Extending into the gland from the capsule are _____, which divide the gland into ______, and transmit blood vessels and nerves.

• there are also fibroblasts, macrophages, dendritic cells, mast cells, plasma cells (IgA), adipose cells, some granulocytes and lymphocytes (lost of immune type cells bc oral cavity is exposed)

•collagen and elastic fibers

capsule

septa

lobules

The superior salivatory nuclei is going to supply the ____________ ganglion

submandibular

The inferior salivatory nuclei is going to supply the ____________ ganglion

otic

nerve supply

parasympathetics

-> preganglionics

• from superior and inferior ________ nuclei in the brainstem

• run with ___ and __

-> postganglionics

• synapse in submandibular or otic ganglion

• run with lingual or auriculotemporal (parotid) nerve

salivatory

VII

XI

VII -> _________ salivatory nucleus

XI -> _________ salivatory nucleus

superior

inferior

The superior salivatory nuclei is going to supply the ____________ and ____________ glands

submadibular and sublingual

The superior salivatory nuclei is going to supply the __________ gland

parotid

The sympathetic innervation is going to _______ the production of saliva or produce a more _______ saliva

- Scared or nervous = mouth goes ___

inhibit

viscous

dry

nerve supply

sympathetics

• follow blood vessels out to the glands

• modulate secretion by __________ blood flow to glands = DEC BF

neurotransmitters:

• ____________ (pregang) and ____________ (postgang)

• substance P and VIP: induce secretion, modulate effects of acetylcholine and norepinephrine, might affect blood flow

• neuropeptide Y and CGRP: _______ blood flow

controlling

acetylcholine

norepinephrine

regulate

• blood is the source of ____ and ___________

• arterioles lead to capillary networks

• blood flow to glands ________ during secretion

• ___________ (inc or dec) pressure in capillaries and venules causes increased production of saliva

fluid

electrolytes

increases

increased

What type of acini does the parotid gland have (+which 2 ducts)?

Pure serous acini

+ fat cells

+ many long intercalated ducts

+ numerous striated ducts

What type of acini do submandibular glands have (+what's different about their ducts?)?

Mixed acini, mostly serous.

+ intercalated and striated ducts less numerous than in parotids

What type of acini do sublingual glands have (+what's different about their ducts?)?

Mixed, predominantly mucous acini.

+ ducts short and difficult to see

What is the primary saliva produced by acinar cells?

Isotonic fluid that contains macromolecular components.

What type of acini do minor glands have (+what's different about their ducts?)?

• mostly mucous

+ short ducts

• secretions rich in mucins, antibacterial proteins, immunoglobulins

• von Ebner’s glands

• located on posterior part of tongue, associated with circumvallate papillae

• secrete enzymes and proteins that impact taste

The fluid and electrolyte portions of saliva come from ______

blood

Water secretion is regulated by ____________ innervation

parasympathetic

What is xerostomia?

Dry mouth due to loss of salivary function or reduction of saliva volume.

What modifications occur to saliva in duct cells?

• transporters cause reabsorption of ___ and ___

• ___ and ___ are secreted

regulation of these actions by

• autonomic nerves

• mineralocorticoids

Na+ and Cl-

K+ and HCO3-

What can cause xerostomia?

Medications, radiation therapy, chemotherapy, and autoimmune diseases.

clinical considerations

•effects of age

• loss of salivary gland parenchymal tissue

• replaced by ________ tissue

• reduced ______ production

adipose

saliva

clinical considerations

disease

• some viruses infect and replicate within salivary gland cells:

• ______________

• __________ virus

• _______ viruses 6 & 7

• _______

• some bacterial infections cause _______ and _______ of salivary glands

cytomegalovirus

Epstein-Barr

herpes

mumps

inflammation

swelling

clinical considerations

disease

ducts can be obstructed by:

• _________ (salivary stones, calculi)

• ______ plugs

• _______ to the ducts

• various _______ can affect the glands

• pleomorphic adenoma

• Warthin’s tumor

sialoliths

mucus

trauma

tumors

clinical considerations

other diseases can affect salivary gland function:

• diabetes

• Sjögren syndrome

• rheumatoid arthritis

• adrenal disease

• AIDS

xerostomia - dry mouth

results:

• dryness of mouth

• loss of protective effects of salivary ________, proteins and mucins

• oral tissues becoming more __________ to infections

• speech, eating and swallowing to become difficult

• teeth become more susceptible to ______

buffers

susceptible

caries