Structure of the airway Flashcards
List the structures that form the conducting and respiratory portions of the respiratory tract
The structures of the respiratory tract;
- Nose, nasal cavity and sinuses
- Nasopharynx and soft palate
- Larynx
- Trachea
- Bronchi and bronchial tree
- Lungs and pleura
- Thoracic wall
- Diaphragm
- Mechanisms of respiration
What does the nose branch off into?
The nose is the external structure which anteriorly encloses the nasal cavities which are held open by bone and cartilage. The entry into the nasal cavities is via the nares. The nasal cavities are located above the oral cavity posterior to the nose and anterior to the nasopharynx
What are the nasal cavities lined with?
The nasal cavities are lined with a highly vascularised mucosal membrane which is lined with Respiratory epithelium
What makes up the respiratory epithelium?
The respiratory epithelium is made up of ciliated pseudostratified columnar epithelium which are interspersed with goblet cells (that secret mucus).
What makes up the respiratory epithelium?
The respiratory epithelium is made up of ciliated pseudostratified columnar epithelium which are interspersed with goblet cells (that secret mucus).
What makes up the respiratory epithelium?
The respiratory epithelium is made up of ciliated pseudostratified columnar epithelium which are interspersed with goblet cells (that secret mucus).
What are special about the cells in the oral cavity?
They are more robust as cells will be damaged when eating food here
What is the Nasal septum?
The nasal septum is a midline structure which separates the left and right nasal cavities.
What is the nasal septum made from?
Anteriorly the nasal septum is made of septal cartilage, while posteriorly the septum is made of bone.
What are the names of the boundaries of the nasal cavities?
Nasal conchae - lateral Bone (ethmoid, frontonasal, sphenoid; roof ) Nasal septum - Medial Hard palate - over mouth Soft palate - further back of mouth
What kind of epithelium is found in the roof and adjacent lateral wall of the nasal cavity and what is its function?
The olfactory epithelium is responsible for smell and is restricted to the roof and adjacent lateral wall
What kind of epithelium is found in the roof and adjacent lateral wall of the nasal cavity and what is its function?
The olfactory epithelium is responsible for smell and is restricted to the roof and adjacent lateral wall
What does the lateral wall of the nasal cavity contain?
The lateral wall of the nasal cavity contains 3 nasal conchae (superior, middle and inferior).
What is the role of the conchae?
The conchae are responsible for providing turbulence and increasing the surface area within the nasal cavity to allow for air flow and better heat exchange - which helps to humidify and moisturise the air being taken in.
What is the role of the conchae?
The conchae are responsible for providing turbulence and increasing the surface area within the nasal cavity to allow for air flow and better heat exchange - which helps to humidify and moisturise the air being taken in.
What are the Meati?
The meati are the spaces behind the Conchae, there’s a superior, middle and inferior
What is missing from the inferior meati that appears in the superior and middle?
The inferior meati does not have an escape area for sinuses
What does the middle meati allow?
The middle meati allows for the joining of spaces that lead into the maxillary sinus
Where is the maxillary sinus located and what routes does it have ?
The maxillary sinus sits just underneath the eye orbit.
It has an escape route into the middle and frontal sinuses (which sit behind the eye brows and eye orbital)
What opens up into the meati and what does this allow?
Adjacent air sinuses open up into the meati, communicating between the sinuses and nasal cavity.
How are our neck muscles able to support the weight of our heads?
Our head contains empty spaces which are sinuses which reduce the weight of the skull.
What is responsible for the clearance of mucus within the maxillary sinus?
Cilia
What could be caused when the cilia compromised by an infection in the maxillary sinus?
Sinusitis
What else can cause sinusitis?
A deviated septum
What is the role of the Nasolacrimal duct?
The nasolacrinal duct enters the nasal cavity to drain tears from the conjunctiva of the eye
What are the 2 places where sinuses are found?
There are frontal sinuses found in the eyebrow region and there are maxillary found in the cheek region
What blood supply is the most common area for rupturing in the nasal cavity?
The blood supply in the Kisselbach area is the most common to receive nose bleeds as it is rich in anastomosing arteries
What is the medical term for a nose bleed?
Epistaxis
Where do the blood vessels in the nasal cavity anastomose (branch off around)?
The blood vessels in the nasal cavity anastomose/branch off from the external and internal carotids arteries
What is the function of the olfactory bulb and nerves, and where are they located?
The olfactory bulb and nerves are responsible for the providing the brain with the sense of smell and are located in the roof and upper parts of the lateral wall
The olfactory nerves sit in olfactory epithelium
What is the pharynx?
The pharynx is the tube of fibrous and muscular tissue that runs from the nasal cavity to the larynx.
What does the pharynx lie behind?
The pharynx lies behind;
- The back of the nasal cavity (Nasopharynx)
- The back of the oral cavity (Oropharynx)
- The larynx (Laryngopharynx)
What is the role of the Nasopharynx and where is it divided from?
The nasopharynx transports air and is divided from the Oropharynx by soft palate
What is the role of the Oropharynx ?
The oropharynx transports air, fluid and food before branching off into the Larynx and Larynogopharynx
What does the larynogopharynx do?
The larynogopharynx transports food and fluid
What is the role of the Larynx?
The larynx transports air
What can happen if food and fluid ends up in the respiratory system?
If food or fluid ends up in the respiratory system this can cause aspiration pneumonia (infection that inflames lungs)
How is food and fluid stopped from entering the larynx?
The epiglottis (functions like a toilet seat) has the capacity to seal off the trachea or larynx
Epiglottis is pulled down slightly to seal off the respiratory inlet when swallowing
What group of muscles are able to shut off the epiglottis?
The Ary-epiglottic fold
How can the Larynx be altered and what for?
The larynx is a membranous tube which is suspended between cartilage, which the positions of them are controlled by muscles.
Laryngeal diameters can be altered to allow the passage of only air, or to control airflow for speech and raising intro abdominal pressure.
Where is the site of emergency access to an airway done?
In the cricothyroid membrane
What is special about the hyoid bone and what is its function?
The hyoid bone is the only bone in the body that isn’t connected to any other bone structures.
Its job is to anchor down the tongue
What is the role of the quadrangular membrane?
The quadrangular membrane is important in sealing the airway off and preventing food and fluid from going into the airway.
Give the parts that make up the quadrangular membrane?
The Aryepiglocc fold is at the upper edge of the quadrangle membrane and the vestibular fold is at the lower edge
Where is the vocal fold located?
The vocal fold is located in the upper edge of the cricothyroid membrane/ cricovocal
What is found in the vocal fold?
The vocal fold is where the vocal chords come from.
There can be nodules that grows on the vocal chords and prevents them from sealing up properly preventing people from singing.
How does the Aryepiglottic fold close off the respiratory inlet?
Closure of the respiratory inlet is done by elevation of the larynx which is lifted up and forwards during swallowing
What is the saccule and where is it located?
The saccule is within the opening of the laryngeal ventricle and is an area that has mucosal glands which are use to help. lubricate the vocal folds
What do the vocal chords control?
The vocal chords control the laryngeal diameter for;
- Speech
- Coughing
- Sneezing
- Raising the intra-abdominal pressure (sealing off the airway allows us to increase the pressure in our abdomen to allow us to force out waste products) - Vital in micturition, dedication and lifting heavy objects
What are the muscles within and adjacent to the vocal chords called and what do they do?
The Rima Glottidis widen the opening or alter their tension
What are the main actions of the laryngeal muscles?
- To close/open the inlet (Ary-epiglocc folds)
- To close/open the rim glocdis (arytenoid gliding and rotation)
- To shorten/lengthen the vocal folds (“rocking” at cricothyroid joints)
What is the only muscle that opens the Rima Glocdis?
The posterior circa-arytenoid is the only muscle that opens the Rima Glocidis
Name the laryngeal nerves and what they supply ?
Superior laryngeal nerve - supplies only 1 muscle and sensation above the vocal chord
Recurrent laryngeal nerve - supplies all other muscles and sensation of vocal chords and below
Where is the trachea located?
The trachea sits in front of the oesophagus, medial to carotid arteries and internal jugular veins and inferior to the larynx
What surrounds the upper portion of the trachea?
The thyroid gland
