[W3] The Nose, Mouth + Throat Flashcards
What are the functions of the nasal cavity?
Warms, humidifies, and purifies inhaled air; drains tears; supports smell.
What bones form the nasal septum?
Anteriorly by hyaline cartilage; posteriorly by ethmoid and vomer.
What is the function of the cribriform plate?
It has holes for olfactory nerves (CNI) to pass, allowing olfaction.
What are the three regions of the nasal cavity?
Nasal vestibule (hairs trap particles), olfactory region (smell), respiratory region (warms/humidifies air).
Why is epistaxis (nosebleed) common?
Due to extensive superficial blood vessels in the respiratory region.
What are the four major paranasal sinuses?
Maxillary, frontal, sphenoidal, and ethmoidal.
What arteries supply the nose?
Ophthalmic and maxillary arteries.
What nerves supply the nose?
CNI (smell), CNV (sensation), CNVII (motor/parasymp), and sympathetic from superior cervical ganglia.
Where are olfactory receptors located?
In the olfactory region of the nasal cavity near the cribriform plate.
How is smell processed?
Odorants bind receptors → CNI → olfactory bulb → olfactory cortex (temporal lobe), amygdala, hippocampus.
Why do we adapt to smells?
Ion channel changes reduce action potentials over time (smell desensitization).
What is the typical range of smells humans can detect?
Around 5,000–10,000 odors.
What are the conditions for a molecule to be smelled?
Must be volatile, water-soluble, and lipid-soluble.
What are the three parts of the pharynx?
Nasopharynx, oropharynx, laryngopharynx.
What are the epithelial types lining the pharynx?
Nasopharynx – ciliated columnar; oro/laryngopharynx – stratified squamous.
What muscles help keep the pharynx open?
Pharyngeal muscles.
What is the function of the constrictor muscles?
They help push food down the esophagus during swallowing.
What cartilages make up the larynx?
Thyroid, cricoid, arytenoid (hyaline), and epiglottis (elastic).
What is the function of the epiglottis?
Prevents food/drink from entering the trachea during swallowing.
What is the glottis?
The space between the vocal cords.
How do vocal cords control pitch?
Adducted cords = high pitch; abducted cords = low pitch.
What are the two parts of the mouth?
Vestibule (outside gums/teeth) and oral cavity (inside).
What is the function of the mouth?
Food intake, chewing, bolus formation, taste, and initial digestion.
What is the epithelium lining the mouth?
Stratified squamous epithelium.
