Oral cavity, salivary glands, and esophagus Flashcards
3 major functions of the oral cavity
- Digestion- receives food, preparing it for digestion in the stomach and small intestine. Beginning of lipid digestion (small amount) occurs here.
- Communication- modifies the sound produced in the larynx to create a range of sounds.
- Breathing- acts as an air inlet in addition to the nasal cavity.
Borders of the nasal cavity
Anteriorly: opening between the lips
Posterior: oropharyngeal isthmus
Regions of the oral cavity
2 regions created by the dental arches:
- Vestibule: Region between lip and teeth. Like pull down lower lip and the dip in there.
- Mouth/oral cavity proper. Enclosed by teeth.
The internal lining of the check is comprised of which type of epithelium?
SSNK. Mucous membrane.
Oral orifice/ oral fissure
Opening between lips.
Which muscle and touch receptors are found in the lips
Orbicularis oris muscle controlled by CN 7
Meissner’s corpuscles for fine touch.
Vermilion border skin
Most peripheral part of lips near skin. Does contain hair and glands.
Vermilion zone
- Which epithelium type?
- Contain hair or glands?
- Red area of lips due to increased vascularization
- Contains SSK epithelium that slightly thickens adjacent to the mucocutaneous junction.
- Lacks hair or glands
Mucocutaneous junction
Transition area from lips to inside mouth. Lips contain SSK and inside mouth, a mucous membrane, contains SSNK.
Outer to inner 3 regions of the lips
Vermilion border of skin, vermillion zone, mucocutaneous junction
___ and __ make up the roof of the oral cavity
Hard and soft pallet.
Hard and soft pallet contain which epithelium type?
SSNK on the oral cavity side, psuedostratified ciliated columnar within the nasal cavity.
What causes a cleft palate?
Maxillary and palatine bones don’t fuse together. This should occur during the 8th-10th week of fetal development.
Linked more so to environmental factors such as diabetic mother or medications taken by mother during pregnancy rather than genetic factors.
What is the anterior and posterior hard pallet made of?
The hard pallet is more anterior than the soft pallet. Made of maxilla (most anterior) and palatine (posterior)
What is the role of the soft pallet and where is it located in relation to the hard pallet?
Soft pallet is important for swallowing. Closes oropharynx from nasopharynx.
Two major regions of the tongue
- Body (oral) Most visible. muscles here are involved with changing shapes.
- Root (pharyngeal). Muscles here are involved in protruding and retracting the tongue.
Arterial supply of the tongue
Lingual artery (brach off the facial, which is a branch off the external carotid)
Musculature of the tongue (2)
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)
- SA (touch)
- GSE
- Facial for anterior 2/3 and glossopharyngeal for posterior 1/3
- Mandibular branch of trigeminal for anterior 2/3 and glossopharyngeal for posterior 1/3
- Hypoglossal primarily. CN XII. Main muscle is genioglossus. Other two are styloglossus and hyoglossus.
How to do CN testing for hypoglossal nerve
Stick out tongue
Palatoglossus is innervated by which CN?
X. The rest of the muscles are innervated by CN XII
Types of lingual papillae
Circumvallate- located in the back center.
Foliate- located in the back sides
Fungiform- located along the sides.
^^ All associated with tastebuds.
Filliform papillae are found in the center of the tongue and are not associated with tastebuds.
Features of a taste bud
Taste pore, supporting cells, basal and sensory cells
How many teeth and what kinds
Incisors- 8 total. 4 top, 4 bottom
Canines- 4 total. 2 top, 2 bottom
Premolars- 8 total. 4 top, 4 bottom.
Molar- 12 total. 6 top, 6 bottom.
3 divisions of a teeth from top to bottom
Top
Crown: Capped by enamel. Hardest substance in the body.
Cervix or neck: Where crown meets root
Root: Located in the alveolus (bony socket for tooth) below gingiva. Cementum surrounds the dentin. Cementum anchors tooth to bone. Holds/cements things in place. Bone and cementum are connectedly periodontal ligaments.
Cementum
Surrounds the dentin. Bony material where enamel stops. Calcified substance and anchors the tooth to bone by connecting periodontal ligaments.
Gingiva (gums)
Fibrous tissue covered by a mucous membrane. Hemidesmosomes bind teeth to gums.
What factors help hold teeth in place?
Cementum that anchors tooth to bone by periodontal ligaments
Hemi desmosomes between gingiva and teeth in basal lamina secreted by epithelium.
Gingival sulcus
Groove between gingiva and tooth. Sealed off by junctional epithelium which prevents infection of the periodontal ligament and loss of teeth from periodontal cavities.
Pulp:
Blood vessels and nerves.
What is dentin (dentine)?
Simular to bone, but avascular. Made by odontoblasts (not osteoblasts) and has dentinal tubules instead of boney canaliculi. Very sensitive, but no nerve endings.
How is the root of the tooth connected to alveolar bone of the maxilla or mandible?
By the periodontal ligament. Composed of collagen fibers that attach to the cementum of the tooth root and the alveolar bone. Contains fibroblasts, vessels and nerves.
Periodontium is composed of which 4 things
Ligament, cementum, gingiva, and bone. Considered a join or articulation.
Mandible role and anatomy
Single bone that makes up the lower jaw. Largest and strongest bone in the face.
Involved in mastication. Chewing.
Anatomy: Mandibular body is horizontal. Angle is 70 degrees. Ramus is almost vertical. At the top, there are two processes. One anterior is called the coronoid process. Attaches to the temporalis muscle. The posterior process is called the condylar process. articulation with mandibular fossa on the temporal bone to form the TMJ.
The coronoid process (anterior) attaches to which muscle
Temporalis.
The condylar process (posterior) attaches to what
Attaches to the mandibular fossa on the temporal bone to form the TMJ.
The TMJ is an articulation between which 3 surfaces?
The surfaces are split by what
Mandibular fossa
Articular tubercle (squamous portion of temporal bone)
Head of mandible (the condyle and the coronoid)
The surfaces are split by the articular disc. It splits the joint into two synovial joint cavities.
The articular surface of the TMJ is covered by what cartilage type?
Fibrocartilage. Tougher and more rare than hyaline cartilage.
Which 3 ligaments stabilize the TMJ
Lateral ligament (stabilizes mandible) and prevents posterior disloation.
Sphenomandibular ligament and stylomanidubular ligament support jaw weight and are both medial to the mandible.
Main muscles that move the TMJ
Muscles of mastication and hyoid muscles.
Muscles of mastication include the masseter, temporalis, and medial/lateral pterygoids. (all paired muscles)
Hyoid muscles include genioyoid, digastric, and mylohyoid.