Upper airway and GIT Flashcards
Recall the functions of the nasal cavities
Warm and humidify air, help trap pathogens
What lies on the lateral wall of each of the nasal cavities?
Nasal conchae
What lies in between each nasal cavity?
Meatuses
Recall the bones that contribute to each nasal concha
Superior and middle conchae = parts of ethmoid bone
Inferior concha = bone in itself
Recall the 4 nerves innervating the nasal cavity, and what they are involved in sensing
- Olfactory nerve - olfaction
- Trigeminal nerve - sensory (V1 = anterior, V2 = posterior)
- Facial nerve - glands
- T1 SNS fibres = VSMCs
Recall the blood supply to the nasal cavity and its clinical relevance
Ant. and post. ethmoidal arteries
Area of significant anastomoses is prone to nose bleeds
Summarise the venous drainage of the nasal cavity
Nasal vein
Facial vein
Pterygoid plexus
Cavernous sinus
Recall each of the paranasal sinuses
Frontal
Ethmoidal air cells
Sphenoid
Maxillary
Recall the relative positioning of the paranasal sinuses in a lateral view
Anterior: Superior to inferior = frontal (eye sockets) maxillary
Posterior to eye sockets, working posteriorly = eye sockets, sphenoid`
Recall the regional mapping of each nasal cavity, and summarise the function of each region
3 regions:
- Nasal vestibule (particle removal)
- Respiratory region (temo and humidity adjustment)
- Olfactory region (olfaction)
Describe the lining of each of the paranasal sinuses
Ciliated and mucous-secreting respiratory mucosa
Describe the innervation of the paranasal sinuses
Branches of the trigeminal
Why do the paranasal sinuses provide a possible route for infection?
Connected to pharynx by small holes
Where do the posterior ethmoidal air cells drain into?
Superior nasal meatus
Which paranasal sinus is the largest?
Maxillary
How may the maxillary sinus in particular provide a route for infection?
Only a thin layer separating it from tooth so tooth infection can infect sinus
What are the 2 functions of the larynx?
Voice box
Valve to close LRT
Recall the structural components of the larynx
3 large unpaired cartilages (cricoid, thyroid and epiglottis)
3 small paired cartilages (arytenoid, cuneiform and corniculate)
Fibro-elastic membrane
From where is the larynx superiorly suspended?
Hyoid
Describe the shape of the thyroid cartilage
Right and left lamina are widely separated posteriorly but converge to join anteriorly
Describe the shape and location of the arytenoid cartilages
Pyramidal
Postero-inferior to epiglottis
Recall the attachments of the vocal folds
Anterior = thyroid cartilage Posterior = arytenoid cartilages
What and where are the false vocal folds?
Vestibular folds = above bioth sides of the true vocal folds
What structures of the larynx must move to affect pitch?
Arytenoid cartilages and cricothyroid joint
Recall the functional components of the facial nerve
Motor - to muscles of facial expression
Sensory - contributes to lingual nerve via CT to supply ant. 2/3 of tongue
PNS - salivary glands (not parotid) and lacrimal glands
Recall the route of the facial nerve
Leaves skull via IAM
Passes through stylomastoid foramen
Supplies face via parotid gland
Recall the pathophysiology of Bell’s palsy
Inflammation of stylomastoid foramen puts pressure on CNVII –> ipsilateral facial paralysis
What function is lost when there is a lesion of the internal laryngeal nerve?
Loss of sensation above vocal folds
What function is lost when there is a lesion of the external laryngeal nerve?
Paralysis of cricothyroid
What function is lost when there is a lesion of the recurrent laryngeal nerve
Paralysis of all muscles of larynx except cricothyroid
Loss of sensation BELOW vocal folds
Summarise the cough and sneeze reflexes and how to differentiate them
Irritation sensed by laryngeal branches of CNX
Phrenic and thoracic nerves initiate deep inhalation
Closed glottis –> pressure buildup
Forced exhalation
Cough only: air escapes via mouth as oropharyngeal isthmus = open
Sneeze only: air escapes via nose as oropharyngeal isthmus = closed
What is the clinical relevance of the relationship between the mastoid antrum and the mastoid air cells
Infection can spread: pharynx –> middle ear –> mastoid process
