Throat Flashcards
What are the 2 parts of the oral cavity?
- Oral vestibule (between lips and teeth)
- Oral cavity proper
What are the boundaries of the oral cavity?
- Lips to palatoglossal arch
- Palate to floor of mouth/tongue
- Buccal mucosa
Stenson’s duct
Parotid duct
Where is the parotid duct located?
The duct pierces the buccinators muscle then opens up into the oral cavity on the inner surface of the cheek, usually opposite the maxillary second molar
Wharton’s duct
Submandibular duct
Where is the submandibular duct located?
Lying superior to the digastric muscle, each submandibular gland is divided into superficial and deep lobes, which are separated by the mylohyoid muscle
What is the lingual nerve a branch of?
The mandibular division of the trigeminal nerve
What does the lingual nerve supply?
General somatic afferent innervation from the anterior 2/3s of the tongue
What nerve fibres does the lingual nerve carry that are not part of the trigeminal nerve?
Chorda tympani nerve of the facial nerve which provides special sensation (taste) to the anterior 2/3 of the tongue
What are the functions of the oral cavity?
- Taste
- Mastication (teeth, tongue)
- Speech (tongue, cheek, lips)
- Digestion (salivary enzymes)
- Swallowing (tongue, hard and soft palate)
What papillae do no contain taste buds?
Filliform papillae
Where does the anterior 2/3s of the tongue originate?
1st branchial arch
What is responsible for the sensation of the anterior 2/3s of the tongue?
Lingual nerve
What is responsible for taste in the anterior 2/3s of the tongue?
Chorda tympani
Where does the posterior 1/3 of the tongue originate from?
3rd branchial arch
what supplies the posterior 1/3 of the tongue?
Cr N IX
What do the intrinsic muscles of the tongue do?
Alter shape
What do the extrinsic muscles of the tongue do?
Alter position
What is the nerve supply to the muscles of the tongue
Cr N XII the hypoglossal nerve supplies all except from the palatoglossus which is supplied by the pharyngeal plexus (CrN IX-X)
What are the functions of the tongue?
- Taste
- Mastication
- Swallowing
- Speech
What are the 4 muscles involved in mastication?
- Lateral pterygoid
- Medial pterygoid
- Temporalis
- Masseter
What nerve supplies the muscles of mastication?
Cr N V3
How is food positioned for grinding by the tongue and cheek?
Between teeth
What are the boundaries of the oropharynx?
- Lower border of soft palate to upper margin of epiglottis
- Palatoglossal arch to posterior pharyngeal wall
- Lateral: faucial pillars and palatine tonsils
What type of epithelium lines the oropharynx?
Stratified non-keratinised squamous
What is the nerve supply of the oropharynx?
Pharyngeal plexus (CrN IX and X)
Where does the blood supply of the hypopharynx come from?
- Superior thyroid artery
- Lingual artery
- Ascending pharyngeal artery
What is the nerve supply of the hypopharynx?
Pharyngeal plexus
What are the boundaries of the hypopharynx?
- Superior margin of epiglottis to lower border of cricoid
- Continuous with oesophagus
- Anterior wall: back of larynx
What are the 3 subsites of the hypopharynx?
- Pyriform sinus
- Post cricoid area
- Posterior pharyngeal wall
What is the nerve supply of the hypopharynx?
Pharyngeal plexus
What are the 3 phases of swallowing?
- Oral phase
- Pharyngeal
- Oesophageal
What is involved in the oral phase of swallowing?
- Tongue propels food (bolus) into pharynx
- Triggering swallowing reflex
What is involved in the pharyngeal phase of swallowing?
- Soft palate pulled upwards
- Epiglottis covers the larynx, vocal cord approximate, larynx moves upward
- Upper oesophageal sphincter relaxes
- Respiration is reflex inhibited
What is involved in the oesophageal phase of swallowing?
- Once bolus passed UOS, the sphincter constricts
- Bolus propelled downwards by peristaltic motion, reflex via myenteric plexus
What are the functions of the larynx?
- Part of the respiratory tract
- Voice
- Swallowing
What are the 3 parts of the larynx?
- Supraglottis
- Glottis
- Subglottic
What are the 7 segments of cartilages that form the larynx?
- Cricoid
- Thyroid
- Epiglottis
- Paired arytenoid cartilages (corniculate and cuneiform)
Where is the supraglottis located?
Extends from the superior tip of the epiglottis to the floor of the ventricular fold (junction of respiratory and squamous epithelium)
Where is the glottis located?
Begins superiorly at the true vocal fold and extends inferiorly to a horizontal plane 5mm inferior to the vocal cord
Where is the subglottis located?
Begins 5mm below the free edge of the true vocal cord and proceeds to the inferior border of the cricoid cartilage
What do the extrinsic muscles of the larynx do?
Move the entire laryngeal complex
What do the intrinsic muscles of the larynx do?
Regulate the movement of the vocal folds
What provides the motor innervation of the larynx?
- Cr N X
- All intrinsic muscles supplied by recurrent laryngeal nerve except cricothyroid muscle (external laryngeal nerve)
What provides supraglottic sensory innervation?
Internal laryngeal nerve
What provides glottis and subglottic sensory innervation?
Recurrent laryngeal nerve
Why does the left recurrent laryngeal nerve have a higher risk of injury during operative chest procedures?
It has a longer course since it loops around the aortic arch instead of the right subclavian artery
Where does the superior laryngeal nerve divide into its internal and external branches?
At the level of the greater cornu of the hyoid
What does the internal branch of the superior laryngeal nerve travel with?
Superior laryngeal artery through the thyrohyoid membrane and allows supraglottic sensation and increased airway protection.
What does the external branch of the superior laryngeal nerve supply?
Subglottic mucosal sensation and motor fibres to the cricothyroid muscle
What are the 5 phases of speech?
- Respiration
- Phonation
- Resonation
- Articulation
- Prosody
What is involved in the respiration phase of speech?
- Source of energy: air flow
- Inhalation and exhalation
What is involved in the phonation phase of speech?
Flow of air through different VC position, tension, vibration and length
What is involved in the resonation phase of speech?
- Oral/nasal speech balance
- Depend on nasopharynx, nasal cavity and oral cavity
What is involved in the articulation phase of speech?
Production of speech, determined by action of lips, tongue and jaw
What is involved in the prosody phase of speech?
- Production of syllable stress and emphasis
- Provide effective speech tone
Prosody
The rhythm, stress and intonation of speech. It is associated with Brodmann areas 44 and 45 (Broca’s area) of the left frontal lobe
