Midterm 2: Oral Cavity Flashcards
Marks the beginning of the alimentary canal
Oral Cavity
True or false:
Absorption of nutrients starts in the oral cavity
False. It begins in the stomach.
What are the 3 major functions of the oral cavity?
Digestion: Receives food, preparing it for digestion in the stomach and small intestine.
Verbal communication: Modifies the sound produced in the larynx to create a range of sounds.
Respiration involvement: The oropharynx communicates with nasopharynx as well as the trachea via the laryngopharynx
What does the oral cavity border anteriorly and posteriorly?
Anteriorly: Oral fissure
Posteriorly: Opening into the oropharynx
Describe your cheeks (no, not butt cheeks). What lines the surface?
Lateral walls of your oral cavity.
Made of internal mucosal lining comprised of stratified squamous non-keratinized epithelium
Describe your lips and areas on lips.
-Two fleshy folds surrounding the oral orifice containing the orbicularis oris muscle (sphincter-like muscle surrounding oral orifice) and Meissner’s corpuscles.
Vermilion border skin:
Most peripheral. Contains hair cells and glands
Vermilion zone:
Red” area of lip due to its vascularization
Contains thin stratified squamous epithelium that slightly thickens adjacent to the mucocutaneous junction
Lacks hair and glands
What is the mucocutaneous junction of the lips?
it is the transition area from stratified squamous keratinized to stratified squamous non-keratinized.
Describe the hard and soft palate
Roof of oral cavity
Stratified squamous non-keratinized on the oral cavity side.
Pseudostratified ciliated columnar within the nasal cavity
Oral cavity anterior to soft palate consists of maxilla (anterior) and palatine facial bones
4 Functions of the tongue
Taste (papillae on dorsal surface)
Chewing
Swallowing
Speech
Arterial supply to the tongue
Mostly lingual artery (branch of EXTERNAL CAROTID Artery)
Musculature of the tongue
Intrinsic: Muscles not attached to bone and affect tongue shape
Extrinsic: Muscles attached to bone and move tongue as a whole
Innervation of the tongue
SVA (taste): Facial/CN VII (anterior); glossopharyngeal/CN IX (posterior)
SA (general touch): Mandibular branch of trigeminal/CN V3 (anterior); glossopharyngeal/CN IX (posterior)
GSE (motor): Hypoglossal/CN XII (primarily)
Function of teeth
Cut and grind food within oral cavity
How many teeth do we have? (List type and amount)
32 teeth total
Incisors = 8 Canine = 4 Premolar = 8 Molar = 12
What is the crown of the tooth capped with?
Capped by enamel. Hardest substance in the body
Where is the root of the tooth?
Located in the alveolus (bony socket for tooth) below gingiva
Cementum surrounding the dentin(e)
What is dentin?
Bony material; starts where enamel stops
Calcified substance and anchors the tooth by connecting periodontal ligaments
Describe the gingiva (gums) and type of epithelium.
Fibrous tissue covered by a mucous membrane Gingival epithelium (near tooth) that attaches strongly to the tooth via hemidesmosomes
What is the groove between gingiva and tooth that is sealed off by epithelium which prevents infection of the periodontal ligament and tooth loss from periodontal disease
gingival sulcus
What features are located externally on a tooth?
Crown
Cervix (neck)
Gingiva
Internal features of a tooth
pulp
Dentin
root of tooth
What makes up the pulp of the tooth?
blood vessels and nerves
Describe dentin
Surrounds pulp
Similar to bone but AVASCULAR
Very sensitive, but no nerve endings
What is the root of the tooth connected to? What is it composed of? What does it contain?
Connected to alveolar bone of the maxilla (upper) or mandible (lower) by the periodontal ligament.
Composed of collagen fibers attached to the cementum of the tooth root and alveolar bone
Contains fibroblasts, vessels and nerves as well.
What makes up periodontium?
Periodontium = Ligament + cementum + gingiva + bone
Describe the temporomandibular joint. What does it articulate between? What are the articulate surfaces covered by and what are they stabilized by?
Specialized joint located anterior to tragus of external ear.
Articulates between. Mandibular fossa, Articular tubercle (squamous portion temporal bone), and head of the mandible.
Articular surfaces covered by fibrocartilage and separated by an articular disc.
Joint stabilized by three ligaments
What are the 3 types of movements of the temporomandibular joint? (JMJ)
1) Protrusion & retraction
2) Elevation & depression
3) Lateral- grinding food
What are the 3 types of movements of the temporomandibular joint? (JMJ)
1) Protrusion & retraction
2) Elevation & depression
3) Lateral- grinding food
What are the muscles of mastication innervated by?
mandibular nerve/CN 5V3 (trigeminal)
What are the 4 muscles of mastication?
1) Masseter
2) Temporalis
3) Medial Pterygoid
4) Lateral Pterygoid
Describe the masseter (superficial to, function)
Most powerful, deep and superficial
Superficial to the pterygoids and temporalis
Actions: elevates the mandible, can cause protrusion
Describe temporalis function
elevates and retracts the mandible
Describe medial pterygoid function
Elevates mandible
Has two heads( deep and superficial)
Describe lateral pterygoid function
Protract the mandible, side to side movement of the jaw. Two heads (superior and inferior)
What muscles assist gravity in depressing the mandible?
geniohyoid and mylohyoid
