Adenoid Anatomy and Function Quiz

Anatomy of the Palate

• The palate is the roof of the mouth, separating the oral cavity from the nasal cavity
• It has two parts:
  • Hard palate (bony) anteriorly
  • Soft palate (muscular) posteriorly

Oral Cavity

• The mouth extends from the lips to the oropharyngeal isthmus
• It comprises two main parts: the vestibule and the oral cavity proper
• Oral Vestibule
  • Boundaries:
    • Anteriorly by lips
    • Laterally by cheeks
    • Posteriorly, medially by teeth and gums
• Oral Cavity Proper
  • Boundaries:
    • Anteriorly laterally by teeth and gums
    • Superiorly by the palate
    • Inferiorly by the tongue and the floor of the mouth
    • Posteriorly by opening into the pharynx

Floor of the Mouth

• Sublingual region structures:
  • Frenulum of the tongue
  • Sublingual papillae (on each side of frenulum)
  • Sublingual fold
• Lingual frenulum (connects tongue to floor of mouth)
• Sublingual fold (passes laterally and backwards from the papilla and overlies sublingual gland)
• Papillae (openings of submandibular duct)

Tongue

• Composed of striated muscular mass, covered by mucous membrane
• Anterior 2/3 (oral part) lies in the floor of the mouth
• Posterior 1/3 (pharyngeal part) lies in the oropharynx
• Muscles:
  • Intrinsic muscles: consist of longitudinal, transverse and vertical fibers; alter the shape of tongue
  • Extrinsic muscles: hyoglossus, genioglossus, styloglossus, and palatoglossus
• Nerve supply: Hypoglossal nerve (except palatoglossus)
• Blood supply: Lingual artery (branches from external carotid)

Posterior 1/3 of the Tongue

• Sensory and taste: glossopharyngeal nerve
• Taste: chorda tympani branch of facial nerve via lingual branch

Hard Palate

• Separates oral cavity from nasal cavities
• Covered by respiratory mucosa (superior surface) and oral mucosa (inferior surface).
• Anterior ¾ formed by maxillae, posterior ¼ by palatine bones
• Anterior and lateral margins are continuous with alveolar arches and gums.

Hard Palate: Features

• Incisive papilla : a small oval elevation over incisive fossa
• Palatine rugae: transverse folds of hard palate mucosa
• Mid-palatine raphe: a median longitudinal ridge

Soft Palate

• It helps close off the nasopharynx during deglutition
• Composed of five muscles:
  • Musculus uvulae
  • Tensor veli palatini
  • Levator veli palatini
  • Palatopharyngeus
  • Palatoglossus

Muscles of Soft Palate

• Actions:
• Bilaterally: Pulls the posterior portion of the soft palate superoposteriorly, separating the nasopharynx from the oropharynx
• Unilaterally: Deviates the soft palate laterally

Palatoglossus

• Origin: Palatine aponeurosis (oral surface)
• Insertion : Lateral tongue to dorsum or intrinsic transverse muscle
• Nerve Supply: Vagus n. (CNX) via pharyngeal plexus
• Action: Pulls the root of the tongue superiorly and approximates the palatoglossal arch, separating the oral cavity from the oropharynx.

Palatopharyngeus

• Origin: Palatine aponeurosis (superior surface) and posterior border of palatine bone
• Insertion: Thyroid cartilage (posterior border) or lateral pharynx
• Nerve Supply: Vagus n. (CNX) via pharyngeal plexus
• Action : Elevates the pharynx anteromedially bilaterally

Vessels of Palate

• Arteries: greater palatine branch of maxillary artery, ascending palatine branch of facial artery, palatine branch of ascending pharyngeal artery
• Veins: generally follow arteries, ultimately drain into the pterygoid plexus of veins in the infratemporal fossa, or into pharyngeal plexus or facial vein.
• Lymphatic: drain into deep cervical nodes.

Nerve Supply to the Palate

• Sensory: greater and lesser palatine nerves, nasopalatine nerve (pterygopalatine ganglion)
• Motor: cranial accessory nerve through pharyngeal plexus (except tensor palati from trigeminal nerve)

Anatomy of Pharynx

• A conical fibromuscular tube forming the upper part of the air and food passages
• 12-14 cm long and 3.5 cm wide at the base; 1.5 cm at the pharyngo-oesophageal junction
• From outwards
  • Mucous membrane: pseudostratified ciliated columnar cells (nasopharynx)
  • Stratified squamous epithelium
  • Pharyngeal aponeurosis: pharyngobasilar fascia; fibrous layer lining muscular coat
  • Muscular coat: longitudinal muscles (internal layer) and constrictors
  • Buccopharyngeal fascia: covers pharynx externally; pharyngeal plexus of nerves

Pharyngeal Muscles

• Stylopharyngeus:
  • Origin: medial aspect of styloid process
  • Nerve supply: glossopharyngeal
• Palatopharyngeus:
  • Origin: upper surface of palatine aponeurosis
  • Nerve supply: pharyngeal plexus
• Salpingopharyngeus:
  • Origin: cartilage of auditory tube near pharyngeal opening
  • Nerve supply: pharyngeal plexus

Pharyngeal Gaps

• First gap (Sinus of Morgagni): Above the margin of superior constrictor; pharyngeal wall is deficient in muscle, completed by pharyngeal fascia and pierced by:
  • Eustachian tube
  • Levator veli palatini
  • Tensor veli palatini
  • Ascending palatine artery
• Second gap: Between superior and middle constrictor and the posterior border of the mylohyoid muscle. It contains:
• stylopharyngeal muscle and glossopharyngeal nerve.
• Third gap: Between the lower border of the middle constrictor and upper border of the inferior constrictor. It contains:
• internal laryngeal nerve and superior laryngeal artery.
• Fourth gap: Below lower border of inferior constrictor. It contains:
  • Recurrent laryngeal nerve and inferior laryngeal artery

Blood Supply of Pharynx

• Arterial:
  • From external carotid artery: Ascending pharyngeal artery, maxillary artery, greater palatine artery, artery of pterygoid canal, tonsillar branch of facial artery; dorsal lingual branch from lingual artery.
• Venous: Pharyngeal plexus drains into internal jugular vein.
• Lymphatic: Deep cervical and retropharyngeal lymph nodes.

Nerve Supply to Pharynx

• Motor: cranial part of accessory nerve through pharyngeal plexus (except stylopharyngeus - supplied by glossopharyngeal nerve)
• Sensory:
  • Nasopharynx: maxillary nerve via pharyngeal branch of sphenopalatine ganglion
  • Oropharynx: glossopharyngeal nerve
  • Laryngopharynx: vagus nerve via recurrent and internal laryngeal nerves

Palatine Tonsil

• Shape: a large ovoid mass of lymphoid tissue resembling an almond; 2 poles, upper and lower; 2 borders, anterior and posterior; 2 surfaces, medial and lateral
• Position: between palatine and tongue; bounded by palatoglossal arch anteriorly and palatopharyngeal arch posteriorly. lies in tonsillar fossa on lateral wall of oropharynx
• Blood supply: descending palatine artery, facial artery, ascending palatine artery, dorsal lingual artery
• Venous drainage: pharyngeal plexus, into lingual vein, some into superior constrictor; some run into veins of the superior and middle constrictor
• Nerve supply: Lesser palatine (maxillary) and glossopharyngeal

Enlarged Adenoids

• Enlarged adenoids are swollen adenoids; a common problem in children
• Causes breathing difficulties (through nose) which may result in dry mouth, cracked lips, runny nose, loud breathing, snoring, restlessness, and sleep apnea

Waldeyer's Ring

• Circular group of lymph nodes in oropharynx and nasopharynx; prevents microorganisms from external environment. Includes nasopharyngeal, tubal, palatine, and lingual tonsils

Killian's Triangle

• Potential gap weak area of pharyngeal wall
• Where perforation can occur during oesophagostomy.

Test your knowledge on the pharyngeal tonsils, commonly known as adenoids. This quiz covers their functions, vascular supply, complications from enlargement, and related symptoms in children. Assess your understanding of this important lymphatic tissue and its implications for health.