Structure Of Upper Respiratory Tract Flashcards
Nose
most superior portion of respiratory tract
Anterior nares open into the enlarged
1. Vestibule- skin lined/ stiff hairs
2. Surface area of nose- doubled by turbinates
Turbinates create
- Superior meatus- olfactory epithelium, cribriform plate, sphenoid sinus
- Middle meatus- sinus openings
- Inferior meatus- nasolacrimal duct
Functions of nose
• Temperature of inspired air (0.25s contact)- 37 degrees
• Humidity (75-80%)
• Filter function
• Defence function- cilia take inhaled particulates backwards to be swallowed
Paranasal sinuses
pneumatised areas of the: frontal, maxillary, ethmoid, sphenoid bones
• Arranged in pairs
• Evagination of mucous membrane from the nasal cavity
Frontal sinuses:
within frontal bone
• Midline septum
• Over orbit and across superciliary arch
• Nerve supply- ophthalmic division of V nerve
Maxillary sinuses
Located within the body of the maxilla
• Pyramidal shape
• Base - lateral wall of the nose
• Apex - zygomatic process of the maxilla
• Roof - floor of the orbit
• Floor - alveolar process
• Open into the middle meatus
• Hiatus semilunaris
Ethmoid sinuses:
between the eyes
• Labyrinth of air cells
• Semilunar hiatus of the middle meatus
• Nerve supply- ophthalmic and maxillary V nerve
Nerve supply of ethmoid sinuses
ophthalmic and maxillary V nerve
Nerve supply of frontal sinuses
ophthalmic division of V nerve
Sphenoid sinuses:
medial to the cavernous sinus
• Carotid artery III, IV, V, VI
• inferior to optic canal, dura and pituitary gland
• Empties into sphenoethmoidal recess, lateral to the attachment of the nasal septum
• Nerve supply - ophthalmic V
Nerve supply of sphenoid sinuses
ophthalmic V
Pharynx
Fibromuscular tube lined with epithelium
• Squamous and columnar ciliated, mucous glands
• Skull base → C6 → Oesophagus
• Anterior → Nasal Cavities, mouth and larynx
3 parts of pharynx
Nasopharynx
Oropharynx
Laryngopharynx (hypopharynx)
Nasopharynx
Bounded by:
• base of skull
• Sphenoid rostrum
• C Spine
• Posterior nose (choana)
• Inferiorly at soft palate opens to oropharynx
• Eustachian tube orifices (lateral wall)- Supply air to middle ear
• Pharyngeal tonsils on posterior wall
Oropharynx
soft palate anteriorly
• Palatine tonsils on the lateral walls- palatoglossal folds and palatopharyngeal folds
• Inferiorly to the hyoid bone
Larynx
• Valvular function- prevents liquids and food from entering lung
• Rigid structure
• 9 cartilages
• Multiple muscles
• Arytenoid cartilages rotate on the cricoid cartilage to change vocal cords
• Innervation- vagus (X)= superior and recurrent laryngeal nerves
Innervation of larynx
vagus (X)= superior and recurrent laryngeal nerves
Superior laryngeal nerve
Provides sensation to larynx
inferior ganglion
• Lateral pharyngeal wall
• Divides into internal (sensation) and external (cricothyroid muscle)
Recurrent laryngeal nerves
all muscles except cricothyroid
• Left- lateral to arch of aorta, loops under aorta, ascends between trachea and oesophagus
• Right- right subclavian artery, plane between trachea and oesophagus
Laryngeal cartilages
• single- epiglottis, thyroid, cricoid
• Double- cuneiform, corniculate, arytenoid
Single laryngeal cartilages
epiglottis, thyroid, cricoid
Sensory Innervation to pharynx
Glossopharyngeal nerve
Nerve innervates muscle of tongue
Hypoglossal
Double laryngeal cartilages
cuneiform, corniculate, arytenoid
Nerve that innervates intrinsic muscles of larynx
Vagus nerve
Larynx moves with speech and swallowing due to action of which muscles
Extrinsic muscles of the larynx (suprahyoid and infrahyoid muscles)
Arytenoid cartilages
Connected to vocal chords
Eustachian tubes
a narrow tube that connects the middle ear to the back of the nose.
Normally, the Eustachian tube opens with every swallow or yawn to act as a pressure-equalizing valve for the middle ear. It also serves to drain the mucus produced by the lining of the middle ear.
What are nares and their structure
Nostrils
Skin lined
Stiff hairs
Sphenoid sinuses
Medial to the cavernous sinus
Very close to Carotid artery, III, IV, V, VI nerves
Inferior to optic canal, dura and pituitary gland (sinus protects the sinus gland)
Empties into sphenoethmoidal recess, lateral to attachment of nasal septum
Nerve supply of sphenoid sinuses
Ophthalmic V
Eustachian tube
Tube from ear empties into Nasopharynx
Obligate nasal breathers
Primarily breathe through nose
Where are turbinates found
Lateral nasal wall
Function of turbinates
Increase surface area
Superior meatus
Olfactory epithelium
Cribriform plate
Sphenoid sinuses
Middle meatus
Sinus openings
Inferior meatus
Nasolacrimal duct
Nares
Nostrils
What is lined by respiratory epithelium
Trachea, bronchi, bronchioles, nasopharynx, sinuses
What is the roof of the nasopharynx lined by
Olfactory epithelium
Reinke’s space
Loose irregular fibrous tissue in the vocal cords
Lies between epithelium and vocal ligaments
