Anatomy of URT

Nose

-extends frm nostrils/nares to choanea
- facial part: - superior part – small nasal bones (medial)
- maxillae (lateral)
- inferior part – lateral and alar cartilages
- alar nasi (flared portion at lower end of nose) – alar cartilage and dense connective tissue

Internal chamber:
- nasal septum (bone and hyaline cartilage) divides nasal cavity into R & L nasal fossae
- roof – ethmoid and sphenoid bones
- floor – palate (separates nasal cavity frm oral cavity)
- vestibule – start of nasal cavity (int. chamber), bordered by ala nasi, stratified squamous epithelium n vibrissae (hair)
- ciliated pseudostratified respiratory mucosa – lines rest of cavity
– non-sensory epithelium
- goblet cells (secrete mucus)
- ciliated cells (drives mucous
twrds choanea)
- nasal conchae – superior, middle, inferior
- inferior conchae – erectile tissue (extensive venous tissue)
- meatus – narrow air passage beneath each conchae; narrowness ensures most air contacts mucous membrane
- olfactory mucosa – contain sensory cells tht detect odours
– covers roof of fossa and parts of septum and sup conchae
- lamina propria – mucous glands
– populated by lymphocytes (immune defense) and plasma cells (secrete
antibodies)
– large blood vessels tht help warm the air

Pharynx (throat)

Nasopharynx

• posterior to choanae and dorsal to the soft palate (uvula)
• receives auditory (Eustachian) tube and houses the pharyngeal tonsil
• inhaled air turns 90degrees downwards
• Passes only air
• Pseudofied columnar epithelium

Oropharynx

• space between soft palate and root of tongue
• contains palatine and lingual tonsils
• Passes air, food and drink
• Stratified squamous epithelium

Laryngopharynx

• begins wth union of nasopharynx and oropharynx at level of hyoid bone
• ends at level of circoid cartilage (start of oesophagus)
• Passes air, food and drink
• Stratified squamous epithelium

Larynx (voicebox)

- passageway for air between pharynx and trachea
- consists of 9 cartilages
- epiglottis: protects trachea frm foreign objects (keeps food and drink out of airway)
- glottis: sound production

~*Shantz*~