The Structure Of The Upper Respiratory Tract Flashcards
What portion of the respiratory tract is the nose?
Most superior portion
What are the functions of the nose?
- humidifies the temperature of the air
- filter function
- defence function (cilia take inhaled particulates backwards to be swallowed)
Where do the anterior nares (nostrils) open into?
The vestibule (area just inside the nostril that leads to the nasal cavity:
- skin lined
- stiff hairs
How is the surface area of the nose increased?
- Doubled by turbinates (small structures / pockets which increases SA so as much air can be humidified before it reaches the alveolus
What do turbinates create?
- superior meatus (The superior meatus is an air passage of the lateral nasal cavity located between the superior nasal concha and lateral nasal wall):
-olfactory
-epithelium
-cribriform plate - sphenoid sinus
Middle meatus:
- sinus openings
Inferior meatus:
- nasolacrimal duct
Where are the paranasal sinuses pneumatised?
- frontal
- maxillary
- ethmoid
- sphenoid bones
How are the paranasal sinuses arranged?
In pairs
What do the paranasal sinuses do?
- evaginate (turn inside out) the mucous membranes from the nasal cavity
- resinates sounds to project it (talking). Works with the voice box
- sinuses are full of mucous same as nasal cavity just an extra space
Where are the frontal sinuses located?
- Within the frontal bone
- Midline septum
- Over orbit and across the superciliary arch (eyebrow)
What is the nerve supply for the frontal sinus?
Ophthalmic division of V nerve
Where are the maxillary sinuses located?
- Within the body of the maxilla
- They have a pyramidal shape:
- Base: lateral wall of the nose (Side)
- Apex: zygomatic process of the maxilla (near cheeks)
- Roof: floor of the orbit
- Floor: alveolar process
Where do the maxillary sinuses open?
Into the middle meatus and hiatus semilunaris
Where are the ethmoid sinuses located?
Between the eyes and like a labyrinth of air cells
How are the ethmoid sinuses drained?
By semilunar hiatus of the middle meatus
What is the nerve supply for the ethmoid sinuses?
The ophthalmic and maxillary V nerve (cranal nerves)
Where are the sphenoid sinuses located?
- Medial to the cavernous sinus
- Carotid artery III, IV, V, VI
- Inferior to optic canal, dura and pituitary gland
Where does the sphenoid sinus empty?
Into the sphenoethmoidal recess, lateral to the attachment of the nasal septum
What is the nerve supply for the sphenoid sinus?
Ophthalmic V
What happens if the sphenoid sinus gets infected?
Can lead to pituitary gland infection which can cause medical problems
Where is the nasopharynx located?
Bounded by the:
- Base of the skull
- Sphenoid rostrum
- C spine
- Posterior nose
- Inferiorly at soft palate opens to: oropharynx
What is the eustachian tube?
- Supplies air to the middle of the ear (allows them to ‘pop’)
- Has orifices (openings) in the lateral wall
- Pharyngeal tonsils on posterior wall
Where is the oropharynx located?
- Back of the mouth
- Soft palate anteriorly
Where are tonsils and their folds?
- Palatine tonsils on the lateral wall
- Palatoglossal folds
- Palatopharyngeal folds (further back and in)
- Inferiorly to the hyoid bone
What is the function of the larynx?
Valvular function:
- to prevent liquid and food from entering the lung
What is the structure of the larynx?
- Rigid structure
- 9 Cartilages
- multiple muscles
How are the vocal chords changed?
Arytenoid cartilages rotate (lengthening and shortening) on the cricoid cartilage to change vocal cords
What different laryngeal cartilages do we have?
Single:
- Epiglottis
- thyroid
- cricoid
Double:
- cuneiform
- corniculate
- arytenoid
What nerves innervate the laryngeal?
The vagus X
- superior laryngeal nerve
- recurrent laryngeal nerve
Where is the superior laryngeal nerve located?
- Inferior to the ganglion
- Lateral pharyngeal wall
What does the superior laryngeal nerve divide into?
Internal : provides sensation to the larynx
External: cricothyroid muscle (little slit below cartilage. If larynx is blocked, put tube in here and could allow breathing)
What does the recurrent laryngeal nerve innervate?
All muscles except the cricothyroid
Where is the left recurrent laryngeal nerve located?
- Lateral to arch of aorta, loops under aorta, ascends between trachea and oesophagus
Where is the right recurrent laryngeal nerve located?
- Right subcalvian artery, plane between the trachea and oesophagus
