Anat 5- oral cavity and pharynx Flashcards
What type of joint is the TMJ, and what are its unique features?
The TMJ is a synovial joint with fibrocartilage lining (not hyaline cartilage). It acts as a modified hinge joint, allowing hinge (elevation/depression) and gliding (protrusion/retraction) movements. The two TMJs function as a couple due to the U-shaped mandible.
Anatomy 5 - Oral Cavity…
What are the movements of the TMJ and the muscles involved?
Elevation (closing mouth): Masseter, temporalis, medial pterygoid
Depression (opening mouth): Lateral pterygoid (initiates), suprahyoid muscles
Protrusion: Lateral pterygoid (primary)
Retraction: Posterior fibers of temporalis
Lateral movements: All muscles of mastication.
Anatomy 5 - Oral Cavity…
What happens during TMJ dislocation, and how is it reduced?
TMJ dislocation occurs when the condyle moves anteriorly past the articular tubercle. To reduce:
Place thumbs on molars.
Apply downward and backward pressure.
Relax the muscles if spasms occur.
Anatomy 5 - Oral Cavity…
What are the key morphological features and innervation of the tongue?
Anterior 2/3: General sensation by lingual nerve (V3); taste by chorda tympani (VII).
Posterior 1/3 and circumvallate papillae: General sensation and taste by glossopharyngeal nerve (IX).
Motor: All muscles by hypoglossal nerve (XII), except palatoglossus (X).
Anatomy 5 - Oral Cavity…
How does the tongue contribute to swallowing?
The tongue pushes the bolus backward during the voluntary phase of swallowing. To test for unilateral paralysis, ask the patient to protrude their tongue; it will deviate toward the paralyzed side.
Anatomy 5 - Oral Cavity…
What is the lymphatic drainage of the tongue?
Tip: Submental nodes
Lateral edges: Submandibular nodes
Midline and posterior: Deep cervical nodes, including jugulo-digastric nodes.
Anatomy 5 - Oral Cavity…
Describe the location and relations of the submandibular gland.
The submandibular gland has a superficial part (below mylohyoid) and a deep part (above mylohyoid). It is related to the lingual nerve, submandibular duct, and hypoglossal nerve. Injury to these nerves during surgery can impair sensation, secretion, or tongue movement.
Anatomy 5 - Oral Cavity…
Outline the secretomotor innervation of the submandibular gland.
Parasympathetic fibers from the facial nerve (VII) travel via chorda tympani to synapse in the submandibular ganglion. Postganglionic fibers then innervate the gland.
Anatomy 5 - Oral Cavity…
What causes a cleft palate, and what are its functional implications?
Failure of the palatal shelves to fuse during embryogenesis causes a cleft palate. This results in feeding difficulties, speech impairments, and increased risk of ear infections.
Anatomy 5 - Oral Cavity…
What are the histological features of the tongue and submandibular gland?
Tongue: Stratified squamous epithelium; taste buds in papillae; intrinsic and extrinsic muscles.
Submandibular gland: Predominantly serous acini with some mucous acini.
Anatomy 5 - Oral Cavity…
Identify key anatomical landmarks on the mandible.
Body: Mental foramen, mylohyoid line
Ramus: Condyle, coronoid process, mandibular foramen
Angle: Attachment of masseter and medial pterygoid.
Anatomy 5 - Oral Cavity…
Name the muscles of the soft palate and their innervation.
Muscles: Tensor veli palatini (V), levator veli palatini (X), palatoglossus (X), palatopharyngeus (X), musculus uvulae (X).
Function: Elevation and tension of soft palate during swallowing.
Anatomy 5 - Oral Cavity…
What is the anatomical structure of the articular disc in the TMJ?
The TMJ articular disc is made of fibrocartilage and divides the joint into two compartments:
Upper compartment: For gliding movements (protrusion/retraction).
Lower compartment: For hinge movements (elevation/depression).
The lateral pterygoid muscle attaches to the disc.
Anatomy 5 - Oral Cavity…
What are the boundaries and contents of the oral cavity proper?
Boundaries:
Roof: Hard and soft palate
Floor: Tongue and mucosa
Anterior and lateral walls: Teeth and alveolar arches
Contents: Tongue, ducts of salivary glands, and openings into the oropharynx.
Anatomy 5 - Oral Cavity…
How does lymphatic drainage of the tongue relate to cancer spread?
Tumors in the lateral tongue spread to submandibular lymph nodes.
Tumors in the apex spread to submental nodes.
Tumors in the posterior tongue drain to deep cervical nodes.
Cancer may metastasize to thoracic duct or right lymphatic trunk.
Anatomy 5 - Oral Cavity…
What are the key roles of the muscles of the soft palate in swallowing?
Tensor veli palatini: Tenses palate during swallowing.
Levator veli palatini: Elevates soft palate to block the nasopharynx.
Palatoglossus and palatopharyngeus: Aid in movement of food to the oropharynx.
Musculus uvulae: Adjusts the uvula position for a tight seal.
Anatomy 5 - Oral Cavity…
What are the relations of the parotid gland, and why are they clinically significant?
Anterior: Mandibular ramus and masseter muscle.
Posterior: External acoustic meatus, mastoid process.
Medial: Styloid process, facial nerve, and external carotid artery.
Surgery on the parotid gland risks facial nerve damage, leading to facial paralysis.
Anatomy 5 - Oral Cavity…
What are the anatomical regions of the pharynx, and what key features are found in each?
Nasopharynx: Tubal elevation, pharyngeal tonsil.
Oropharynx: Palatine tonsils, vallecula.
Laryngopharynx: Piriform recess, inlet of larynx.
Anatomy 5 - Oral Cavity…
What ligaments stabilize the TMJ, and what are their roles?
Lateral ligament: Prevents posterior dislocation.
Capsular ligament: Encloses the TMJ.
Sphenomandibular ligament: Acts as a passive support for the mandible.
Stylomandibular ligament: Limits excessive protrusion.
Anatomy 5 - Oral Cavity…
What are the functions of the longitudinal muscles of the pharynx?
Elevate the pharynx and larynx during swallowing and speaking.
Include stylopharyngeus (IX), salpingopharyngeus (X), and palatopharyngeus (X).
Anatomy 5 - Oral Cavity…
