Chapter 11 FP, Chapter 7 FH- Head and Neck Structures/ Glandular Tissue- Orofacial Anatomy

Test 2

head and neck structures

salivary glands

parathyroid glands

thyroid glands

lacrimal glands

lymphatic gland

thymus gland

nasal cavity

paranasal sinuses

gland properties

a structure that produces a secretion necessary for body functioning

exocrine gland

has duct, empties directly into the location to be used

example: saliva glands

endocrine gland

no duct, directly into the bloodstream then carried to distant location

2 types of glands

exocrine gland and endocrine gland

Lacrimal glands

Secrete lacrimal fluid, has both epithelial and lymphatic tissue

Lacrimal fluid

Tears, lubricate eyelids and eyeball

2 parts of lacrimal gland

Palpebral

Orbital

Palpebral

on the bottom, smaller, closer to the eye

can be seen when upper eyelid is inverted

Orbital

on the top, larger, superior to the palebral

Lacrimal gland located

within the lacrimal fossa

Ducts

both orbital and palpebral parts combine lacrimal fluid

travel to lacrimal punctum (small hole)

excrete onto face OR. in naslolacrimal sac

then drain into the inferior nasal meatus

cause

salivary gland properties

produce saliva

controlled by ANS

major or minor

saliva

immunoglobulins

minerals

electrolytes

buffers

enzymes

metabolic waste

Saliva Pros

Lubricates

cleanses

protects

digestion (enzymes)

buffers (bicarbonate and phosphate, keep PH stable)

Antibacterial activity (lysozyme, IgA, lactoferrin)

Maintains tooth integrtity; enamel remineralization (calcium and phosphate)

Saliva Cons

dental biofilm (part of plaque) formation

supplies minerals for calculus mineralization

demineralization

histology of salivary glands

epithelium cells: line the ducts & produce saliva

connective tissue: surrounds epithelium, protection & support, make capsule and septa

capsule

surrounds outer part of gland and septa

septa (septum)

divides the inner part of the gland into lobes, and then smaller lobules

likes rivers

acinus (acini)

group(s) of secretory cells; resemble grapes

terminal part of the gland within lobules

single layer of cuboidal epithelial cells surrounding a lumen

lumen

central opening where the saliva is deposited after being produced

serous- serous cells

watery and serous secretion

narrow lumen (tiny center)

proteins and glycoproteins/ Produce amylase: begins digestion

thin icing tip

mucous- mucous cells

thick

viscous, mucous secretory product

wider lumen

lubricates and forms a surface barrier against microorganisms (like motor oil)

thick icing tip

mucoserous or seromucous

mixed secretory product

can have both cell types

mixed product within one cell type predominating

either more mucous or more serous

Myoepithelial cells

end of acini

help facilitate the flow of saliva

on the surface of some acini

contractile nature; squueze the saliva out of the lumen

ductal system

hollow tubes

progressively grow larger from the inner to the outer parts of the gland

lined by the epithelium

parts of the ducts

intercalated duct

striated duct

excretory duct

intercalated duct

associated terminal part

hollow tube lined with single layer of cuboidal cells

contribute lysozyme and lactoferrin- break down bacteria and viruses

striated duct

connected to the intercalated ducts but longer

single layer of columnar cells- lengthened

resorbs and secretes electrolytes into saliva from blood- buffering action

excretory duct

final part located in the septum

larger than striated

saliva exits and enters oral cavity

pseudostratified columnar epithelium→stratified cuboidal epithelium

3 major salivary glands

parotid

submandibular

sublingual

parotid salivary gland

largest encapsulated

25% total volume of saliva

behind mandibular ramus (in front of TMJ)

serous acini only

associated with parotid duct and Stenson’s duct

opens in oral cavity at parotid papilla

parotid salivary gland associated with

parotid duct or Stenson’s duct

2 lobes in the parotid salivary gland

superficial (at surface)

deep (lower)

submandibular salivary gland

2nd largest

60-65% of saliva produced here

located in the submandibular fossa for protection

seromucous acini

opens at sublingual caruncle

submandibular salivary gland associated with

submandibular duct or Wharton’s duct

sublingual salivary gland

smallest

only un-encapsulated (no CT sheath for protection)

10% volume of saliva

located in sublingual fossa anterior to the submandibular salivary glands

mucoserous

shares the the openings as the submandibular duct-share caruncle

sublingual salivary gland associated with

sublingual duct and Bartholins’s duct

minor salivary glands

smaller but more numerous

exocrine glands

scattered in oral cavity

mostly mucous acini, few serous

keep tissue moist

exception to mucous acini

Von Ebner’s glands

only serous acini

associated with circumvallate papillae

aging salivary glands

30%-60% of salivary glands lost with age

duct systems undergo change

stimulation of saliva less, but production of saliva remains the same

nerve issue, reaction slows

hyposalivation=

xerostomia

xerostomia

increases trauma, caries

less protection

diabetes, Sjogren syndrome, rheumatoid arthritis

radiation for head and neck destroys salivary glands

changes in dental treatment

sialolith

salivary stone- blockage; calcified

ducts blocked

mucocele

minor (on lip)

ranula

major (on floor of the mouth)

mucocele and ranula

lesion caused by retention of saliva in gland

treated by removal of sialoth or entire gland

lingual tonsils

located on base of the dorsal surface of the tongue

posterior to circumvallate papillae

indistinct layer of diffuse lymphoid tissue (can hardly see)

palatine tonsils

tonsils we check

2 rounded masses of different sizes

located between anterior and posterior faucial pillars

contains fused- together lymphatic nodules

swell if sick or have allergies

thyroid gland

largest endocrine gland

located anteriorly and lateral regions of the neck, inferior to the thyroid cartilage

ductless

thyroxine: metabolic rate

2 lateral lobes connected by the isthmus

thyroid gland development

1st endocrine gland in development (24th day in embryo)

from median down growth from the foramen cecum

foramen cecum

begins the opening of thyroglossal duct

thyroid gland: clinical considerations

disease or endocrine disorder

thyroid gland becomes enlarged

goiter

goiter

viewed during the extraoral exam

firm and tender when palpated

medical referral

parathyroid glands

4 small endocrine glands: 2 on each side

adjacent to or within the thyroid gland on its posterior surface

not visible or palpable

produce and secrete parathyroid hormone

regulate calcium and phosphorus level

thymus gland

endocrine gland

part of the immune system

t-cell lymphocytes, WBCs mature in the gland

grows from birth to maturity

shrinks after puberty & returns to weight present at birth at adulthood

located at the base of the neck, inferior to the thyroid gland

not palpable

nasal cavity properties

inner space of the nose

communicates with the exterior by 2 nares

nares are separated by the midline

nasal septum

nasal septum also divies

the internal nasal cavity into 2 parts

nasal conchae

3 projecting structures located on each lateral wall, extend inward

beneath each concha are openings through which the

paranasal sinuses or nasolacrimal ducts

nasal cavity lined by a respiratory mucosa

pseudostratified columnar epithelium

goblet cells

the moist mucus forms a superficial coating on the respiratory mucosa

cilia

superficial coating; ciliary action posteriorly to the nasopharynx (similar to filiform)

foreign materials

are trapped and removed in cilia

paranasal sinus properties

paired air-filled cavities in bone

air filled cavities in bone

frontal, sphenoidal, thmoidal, and maxiallry

paranasal communicates with nasal cavity through small openings in the lateral nasal wall called

OSTIA

ostia

holes in cribiform plate

ostia main serve is to

lighten the skull, resonate sound, and provide mucous for the nasal cavity

paranasal sinus similar to

nasal cavity

paranasal sinus lined with

respiratory mucosa consisting of ciliated pseudostratified columnar epithelium

sinusitis

inflammation of the nasal cavity and paranasal sinuses

sinusitis and maxillary posterior teeth

in close proximity to the maxillary sinus

can sometimes result as infection spreads from a periapical abscess assocaited with a maxiallry posterior tooth

frontal

located within the frontal bone superior to the nasal cavity

approx 2 to 3 cm

asymmetric

L and R separated by a septum

each one communicates with and drains into the nasal cavity by way of frontonasal duct

sphenoidal

located deep within the body of the sphenoid bone

cannot be palpated

approx 1.5 to 2.5 cm

asymmetric

comm. with and drain into the nasal cavity by the opening on each superior nasal concha

can’t see

ethmoidal

a variable number of small cavities

located deep within each lateral mass of the ethmoid one

cannot be palpated

divided into the anterior, middle, posterior

by the bridge of nose

maxillary

located within the body of the maxillae; posterior to the canines and premolars

size varies by age

usually largest paranasal sinus

drains into the middle meatus on each side by ostium (opening)

because of the position of the ____

gravity cannot drain the maxillary sinus contents when the head is erect