The Airways Flashcards
(53 cards)
Respiratory system comprises:
Nose, pharynx, larynx, trachea, bronchi and lungs.
Classification:
> Upper airways:
Nose
Pharynx
Associated structures.
> Lower airways: Larynx Trachea Bronchi Lungs 5
The nose
- Provides an airway for resp.
- Moistens and warms air
- Filters inhaled air
- Resonating chamber for speech
- Houses olfactory receptors
- External nose and internal nasal cavity
External nose:
Apex and root
-dorsum, nares (nostrils), alae and vestibule
Bony framework
– Nasal part of frontal bone, nasal bones, frontal processes of maxillae and bony parts of nasal septum
Cartilaginous framework
– septal cartilage, 2 lat. nasal cartilages, and 2 alar cartilages
Nasal septum
- 1/2s nasal cavities
- Found between nares ant. and choanae post.
- Inf. 2⁄3 of made up of nasal mucosa = Respiratory area, warms
and moistens air - Sup. 1⁄3 = Olfactory area for smell
Components:
Bony part
- Perpendicular plate of ethmoid bone, Cribriform plate and crista
galli
- Vomer --> Postero-inferior part
Cartilaginous part
- Septal cartilage (hyaline cartilage)
Nasal cavity: BoundariesLook at nasal 1 - 7 diagrams
Nasal cavity: Boundaries
Roof:
Nasal, frontal, sphenoid, cribriform plate of ethmoid
Floor:
Maxilla and palatine bones
Medial wall: (septum)
Ethmoid (perp. Plate)
Vomer, septal cartilage
Lateral wall:
Three shelves, formed by projections of the sup., middle, and inf. nasal conchae, extend out of each lat. wall
= nasal conchae (actual bones) / turbinates (still covered by resp. epithelium.)
Clean and humidifies air
Meatuses – groovelike passageways
Posterosuperior spheno- ethmoidal recess
Lateral wall of the nasal cavity contains the following openings:
Sphenoethmoidal recess - Between sup. Nasal concha and sphenoid - Contains opening from sphenoid sinus Superior meatus - Inf. To sup. Nasal concha - openings of post. Ethmoidal air cells Middle meatus - Inf. To middle nasal concha - Opening for frontal sinus (nasofrontal duct) - Middle ethmoidal air cells (ethmoidal bulla) - Ant. Ethmoidal air cells - Maxillary sinus (hiatus semilunaris) Inferior meatus - Inf. To inf. Nasal concha - Opening for nasolacrimal duct (drains tears from Eye)
Paranasal sinuses
air-filled extensions of respiratory part of nasal cavity into frontal, ethmoid, sphenoid bone and maxilla
Functions:
↑ surface area for cleaning & humidifying air
and lightens weight of skull
Arterial supply of the nasal cavity:
Branches off one another:
1. Internal carotid artery - ophthalmic artery - Ant. And post.
Ethmoidal arteries
2. External carotid artery - Maxillary A - Sphenopalatine artery
3. External carotid artery (External nose from other branches) -
Facial artery - Septal branches
Venous drainage of the nasal cavity:
Medial & lat. Walls drain via submucosal venous plexus into sphenopalatine, facial & opthalmic vv.
–> Thermoregulation (altering the temperature of air.)
Nerve supply of nose
Opthalmic n. Branch of Trigeminal n – cranial n V1 • Anterior and posterior ethmoidal nn. from nasociliary n. Maxillary n. Branch of Trigeminal n – cranial n V2 • Nasopalatine n. - septum • Greater palatine n. - lateral wall Dorsum & apex: Mostly opthalmic n. • Infratrochlear n. • Anterior ethmoidal n. Alae: Maxillary n. • Infra-orbital n.
Pharynx
• Extends from the skull base to the inferior border of the cricoid
cartilage (at the level of C6), and is continuous with the esophagus
• Ant. to vertebral bodies
•Divided into 3 parts according to the part with which it communicates:
nasopharynx, oropharynx and laryngopharynx
Nasopharynx
Posterior to nasal cavities
superior to soft palate
Begins behind Choanae
Nasopharynx Contains lymphoid tissue:
- pharyngeal tonsil (adenoids) in roof & post. Wall
- tubal tonsils adjacent to opening auditory tube
Openings of pharyngotympanic tubes (Eustachian) on lat. walls
- connect the nasopharynx to each tympanic cavity.
- Equalize pressure middle ear with atmospheric pressure
Pharyngeal recess
Respiratory function
Pharyngotympanic tube
- Part of nasopharynx
• Opening post. to inf. nasal meatus
• Posterolat. 1⁄3 is bony remainder cartilaginous
• Equalize pressure middle ear with atmospheric pressure
• Opened by mm.levator veli palatini & tensor veli palatini
• Salpingopharyngeal fold covers those muscles
• Tubal tonsils adjacent to openings of tubes
Pharyngotympanic tube
Oropharynx
- Posterior to oral cavity
- Boundaries:
• Extends from soft palate sup. to sup. border epiglottis
• Palatoglossal and palatopharyngeal arches laterally
• Soft palate sup. & base tongue inf. - Lymphoid tissue:
o Palatine tonsils between palatoglossal and palatopharyngeal arches/folds
o Lingual tonsils on post. third of tongue - Digestive function
Laryngopharynx
- Posterior to the larynx.
- Ant.C4–C6
- Extending from the superior border of the epiglottis to the inferior border of the cricoid cartilage.
- Walls Constrictor muscles
- Laryngeal inlet. (entrance)
- Piriform fossa (recess) – where inhaled objects can get stuck
Laryngopharynx is a shared pathway for food and air.
Food:
Moves from the oral cavity, through the oropharynx and then into the esophagus
Air:
Nasopharynx/Oropharynx – depends on if you’re mouth breathing or not –> into the larynx
[So overlap]
When a bolus of food is swallowed – pushes epiglottis closed – so it flaps down over the opening of the larynx = food directed into esophagus
