Lab - Oral Cavity

Dr. Crissman has posted the lab powerpoint on the academic intranet – some slides are used here.

MCW 025 – Lip, H&E Orbicularis oris muscle

Oral mucosa

Thin skin (external surface)

Characteristics of the lip: •

Mucosal type stratified squamous epithelium (on buccal/oral side)

•

Keratinized stratified squamous epithelium w/ hair follicles and sebaceous glands (on other side)

•

Orbicularis oris muscle

Dermal papillae – extend deeply into epithelium and contain numerous capillaries, p. 97

Mucosal type stratified squamous epithelium

hair follicle (this is a whisker from a cat) Orbicularis oris (skeletal muscle) – innervated by buccal branch of facial nerve (CN VII)

Sebaceous gland

Keratinized side – has hair follicles and sebaceous glands

Hair follicle

Sebaceous gland

Keratinized stratified squamous (higher mag)

Hair follicle

Vermilion border

Orbicularis oris

Vermilion border (a.k.a. mucocutaneous junction) – the transition zone between the two types of epithelium of the lip: a) keratinized stratified squamous, b) mucosal stratified squamous –p. 97

Labial gland (salivary)

UW 042 Hair follicles associated with keratinized side

Intrinsic muscles - Bundles of muscles in various directions (innervated by hypoglossal nerve)

Circumvallate papilla

Von Ebner’s glands - serous

Taste buds – in epithelium lining moat

NOTE: circumvallate papillae inervated by glossopharyngeal nerve despite being in front of sulcus terminalis

Lamina propria

Epithelium of papilla is stratified squamous non-keratinized

Secondary papillae of lamina propria protrude into the epithelium, p. 98

Mucus glands – lighter staining that serous glands

Von Ebner’s glands – serous; open into the moat surrounding papilla

SL049 – Tongue, Vallate papilla

Circumvallate papilla

Taste bud

Serous glands of Von Ebner’s

MCO 0029 - Tongue, Mammal

Skeletal muscle

Thin lamina propria

Dorsum of tongue – has filliform papillae

NOTE: tooth pointing downwards

Alveolar bone

Artery, vein, and nerve in canal

Pulp cavity– in the center of the tooth and root canals; contains blood vessels, nerves, and CT. -p. 99

Gingiva Apex of tooth

NOTE: enamel has been removed during decalcification process, so will see dentin but not enamel here. Root – part of tooth covered by alveolar bone Crown – part of tooth visible in oral cavity

vein

nerve

arteries

bone

Gingival sulcus dentin

dentin

predentin

Odontoblasts (lining pulp cavity)

bone

cementum

Periodontal ligament – attaches cementum (on dentin) to the alveolar bone. The fibers that extend into the bone for a short distance are called Sharpey’s fibers. p. 99

dentin

Developing Tooth Cap stage

Late bell stages

bone

Dental sac – CT that surrounds enamel organ and dental papilla

Dental papilla

HERS (Hertwig epithelial root sheath)

Inner enamel epithelium Stellate reticulum

Enamel organ

Enamel organ – appears like an inverted cup; composed of loosely arranged, light staining cells; contains an inner layer of dark fibers and cells called ameloblasts, p. 100

odontoblasts dentin

ameloblasts

dental papilla

Outer enamel epithelium

Enamel (dark-staining in this slide)

Stratum intermedium – supports the ameloblasts Stellate reticulum – loosely fills enamel organ Outer enamel epithelium – forms the outer boundary of enamel organ p. 100

predentin

odontoblasts

dentin enamel

IEE = Inner enamel epithelium OEE = outer enamel epithelium SR = stellae reticulum

UTN 082 - Enamel Organ, Pig (Triple)

ameloblasts

dentin

odontoblasts

enamel

Parotid Gland

Parotid gland - serous secretions

Serous acini

Intercalated ducts: •Smallest - same size as acini •Difficult to recognize, easiest to see in parotid gland •Drain acini & tubules •Simple cuboidal cells & some myoepthelial cells (from lecture notes)

Striated ducts -No CT surrounding - Striations due to numerous mitochondria & membrane infoldings

Interlobular ducts – has CT around

Submandibular gland - MCO 0081

-mixed gland (but predominantly serous)

Sublingual gland Mixed gland, but predominantly mucus secretions