Histology of the Derivatives Pharyngeal Arch Region (Exam 1) Flashcards
Ant. 2/3 (moveable) Dorsal surface has:
SSK epithelium
Ectoderm germ layer
Specialized Mucosa
Ant. 2/3 (moveable) Ventral surface has:
SSNK
Endoderm
Lining mucosa
Posterior 1/3 (immovable) Dorsal surface:
SSNK
Endoderm (Hypobrachial emmence 3rd/4th PA
Lining mucosa
What is specialized Mucosa:
Refers the presence of surface elevations known as lingual papillae– Lingual papillae may contain taste buds
The only place where lingual papillae is:
Specialized Mucosa, which is found mainly on the dorsal surface of anterior 2/3 of tongue
Skeletal muscle extrinsic and intrinsic tongue muscle is:
Derived occipital somites- Primarily hypoglassal nerve
Name the four types of lingual paella in Ant 2/3:
Filiform
Fungiform papillae
Foliate
Circumvallate (vallate)
Describe Filiform Papillae
Located: Scattered amount fungiform papilla on dorsal surface of anterior 2/3.
- Conical in shape, extensive keratinization
Innervation (GSA): Branch of Trigeminal V3— Pain and Temp
Describe Fungiform papillae:
Contain taste buds (Red vascularized)
Located: scattered over dorsal surface of anterior 2/3 tongue.
Round shape, variable height; highly vascularized CT
Innervation: (SVA); chorda tympani (branch of VII)– Innervation to taste buds
Describe Foliate papillae:
Contain taste buds
Located along posterior lateral surface of anterior 2/3
Conical shape, same height, rudimentary in man; associated with serous glands
Describe Circumvallate (Vallate):
Contain taste buds
Located: anterior to the sulcus terminals; anterior 2/3 dorsal surface of tongue
Large domed shaped papillae; serous salivary glands (glands of Von Ebner)
Innervation: (SVA) glossopharyngeal (Branch of IX) (3rd arch)
Describe taste buds:
Taste buds are chemoreceptive cells associated with most papillae or scattered in the oral Mucosa. Each bud composed of four sensor cell (neuroepithelial) types:
Type I supporting cells
Type II and II neuroepithelial receptor cells
Type IV basal (regenerative): stem cells
Sour, Bitter, Sweet, Salty, Unami
Can be found on: Fungiform, foliate, circumvallate papila
What is a taste Pore?
Small opening at the apex of taste bud; Serves as site of sensory transduction. `
Features of Ventral Tongue– Ant 2/3
Lining mucosa: SSNK and underlying CT
Lingual papillae absent
Mixed minor salivary glands open onto ventral surface– glands located near tip
All taste buds are capable of detecting each test modality due to:
Different sensory receptors
Taste buds may also be scattered without papillae in:
Posterior 1/3; Epiglottis, soft palate
Describe the Ventral tongue anterior 2/3
Lining mucosa- SSNK and underlying CT
Lingual papillae absent
Mixed minor salivary glands open onto ventral surface– glands located near tip
Name the three types of minor salivary glands in tongue:
Serous
Mucous
Mixed
Describe Serous salivary glands:
Glands may secrete a watery (serous) secretion and stain very eosinophilic, nuclei are rounded, Known as glands of Von Ebner
- Anterior to sulcus terminalis region of circumvallate papillae, foliate papilla
Describe Mucous salivary glands:
Mucous glands may secrete a viscous (mucous) secretion and appear pales staining due to mucin, nuclei flattened at cell base
- Posterior 1/3 of tongue (Also found in soft palate)
Describe mixed (seromucous) salivary glands:
Produce a mixed secretion. Serous cell “ sits” on top of mucous cell- Serous cell called serous demilune (SD)
Note* Often the mixed gland may be more serous or produce a predominately mucous type of secretion.
- Anterior 2/3 near tip open onto ventral side; Will look largely mucous. Also on the lavial surface (lip) and buccal surface, pharynx, and larynx
Where are the laryngopharynx and larynx:
Both corresponds to region between the epiglottis and cricoid cartilage and is derived from 4th and 6th arch. The larynx sits anterior to laryngopharynx.
What is the Pharyngeal (adenoids):
Single structure in the midline of the roof of the nasoparynx
What is the Palatine:
Bilateral; posterior to palatoglossal folds in oropharynx
