Unit 13: The airways Flashcards
What makes up the laryngeal skeleton?
The hyoid bone
Thyroid cartilage
The cricoid cartilage
Describe the shape of the cricoid cartilage
A complete signet shaped ring with a broad aspect posteriorly
Describe the anatomical location of the cricoid cartilage relevant to other structures
In adult male cricoid cartilage is found midway (3-4cm) between the hyoid bone and the tracheal notch
What is the role of the cricothyroid joints?
Contracts to allow the cricoid cartilage and the thyroid cartilage to move independently and as a unit.
What is the role of the cricothyroid muscle?
Pull the thyroid inferior and anterior relative to the cricoid
This elongates the vocal cords
What si the cricothyroid membrane/ligament?
Attaches anteriorly in the midline, connects the cricoid and thyroid cartilages
Also attaches to the vocal process at the arytenoid cartilage, has a free thickened upper border which forms the vocal ligament and contributes to the vocal cords
What are some of the internal structures found in the larynx?
The epiglottis
Arytenoid cartilages
Cuneiform cartilage
Corniculate cartilage
Vocal cords.
What is the epiglottis?
Curved and leaf-shaped in structure
Folds over the glottis
Directs food and liquid into the oesophagus by closing over the larynx.
Where are the arytenoid cartilages found?
On the upper posterior rim of the cricoid cartilage
What is the purpose of the cuneiform and corniculate cartilage?
Found on top of the arytenoid cartilage - adds shape and bulk to mucosal folding
What are the vocal folds?
Ligaments from arytenoid to inside mid point of thyroid cartilages, ligaments can be tensed by muscles to open and close.
When do the vocal cords tend to move?
Open on inspiration
Close on expiration and when protecting the larynx
Vibration of the cords - produces sound
Change in thickness or tension of the cords alters pitch
What is the glottis?
The opening between the vocal folds in the larnyx
Passage between the lungs and the mouth.
What makes up the nasal cavity?
We have two separate cavities - separated by the nasal septum
Each cavity contains a superior, middle and inferior nasal conchae called turbinate bones.
The spaces between these bones makes up the sphenoidethmoid recess, superior meatus, middle meatus and the inferior meatus.
What is the purpose of the conchae in the nose?
Where air is swirled, warmed, filtered and humidified - part of the conducting system.
What is the different neurovascular content in the nasal cavity?
CN1 - the olfactory nerve
CN5 - general sensation
What is the role of CN1 in the nasal cavity?
Branch into the nasal septum and the lateral nasal wall
Provides sense of smell.
Olfactory nerves in the cavity communicate with the olfactory nerve which project to the brain via the olfactory tract.
Cass through the cribriform foramen in the ethmoid bone in order to get into the nasal cavity.
What are the different boundaries of the nasal cavity?
Anteriorly - the nares (or nasal vestibule)
Posteriorly - the choanae - gives rise to the nasopharynx in direct communication to the oropharynx.
Superiorly - parts of the frontal, ethmoid and sphenoid bones - separate from the cranial cavity
Inferiorly - the hard palate, division from the oral cavity
What are the different paranasal sinuses?
The frontal
The maxiallary
Sphenoidal
Ethmoid cells
2x of each
What are the different regions of the nasal cavity?
The olfactory (superior)
THe respiratory resgion (bulk of body)
The vestibule (opening at the nostrils)
What is the role of trigeminal nerve in the nasal cavity?
Provides general sensation - pain, temp, touch
Branches into nasal lateral wall, nasal septum and the hard palate
Enters the nasal cavity through the maxillary sinus.
What is the role of the nasolacrimal duct?
Lacrimal gland - tears into eye
Excess tear drain into the lacrimal canaliculi in the medial corner of the eye, drains into lacrimal sac then lacrimal duct - this empties into the inferior meatus in the nasal cavity.
Bilateral structure - one for each eye.
What are paranasal sinuses?
What is their function?
Hollow chambers in the skull
Increase sound resonance
Reduce weight of skull
Humidify and heat inspired air
Help protect from rapid temperature changes in the nose
Buffer aginst facial trauma.
Label the different paranasal sinuses.
Green - frontal
Blue - ethmoidal
Purple - maxillary
Red - sphenoidal.
Label the different paranasal sinuses on the x-ray?
Yellow - frontal
Green - ehtmoidal
Red - sphenoid
Yellow - maxillary
Blue - nasal cavity
What nerve innervates the paransal sinus?
Trigeminal nerve mainly V1 and V2.
What is the role of the pharnygotympanic tube related to nasal cavity?
Located in nasopharynx - links nasopharynx to middle ear, typically opened during swallowing.
Aerates middle ear and clears any mucus into the nasopharynx from the ear
However in children allows infection spread from nasal cavity to middle ear as more horizontal in shape and tend to lye on back a lot.
Label the following image
Inferior conchae
Soft palate
Nasopharynx
Opening of the pharyngotympanic tube
Middle concha
Superior concha
Where do the different paranasal sinuses drain into the nasal cavity?
- Sphenoidal sinus - into sphenoethmoidal recess
- Posterior ethmoidal cells into superior meatus
- Middle ethmoidal cells in ethmoidal bulba in middle meatus
- Anterior ethmoidal cells and frontal sinus - into infundibulum - frontonasal duct - middle meatus
- Maxillary sinus into the middle meatus in the floor of the semilunar hiatus.
What structure is the continuation of the larynx?
The trachea
What are the different divisions after the trachea?
Primary bronchi
Lobal bronchi - righ tlung has 3 left only has 2
Tertiary or segmental bronchi
What is the mediastinum?
Central chest - between the pleural cavtities, continas the heart in the pericardium.
What is the role of the pleura?
Reduce friction
Protection
Aid ventialtion - creates surface tension to move lungs with ribs.