Respiratory tract anatomy Flashcards
Innervation of the Tensor Tympani and Stapedius
Tensor tympani: Mandibular nerve (CN Vc)
Stapedius: Cranial nerve VII
Innervation of the Tympanic membrane
Tympanic branch of the glossopharyngeal nerve.
Auriculotemporal branch of the Mandibular nerve
Auricular branch of the Cervical Plexus
Innervation of the Auricle/Pinna
Auricular and auriculotemporal branches
Innervation of the Middle Ear
Tympanic branch of the Glossopharyngeal Nerve
Function of the Eustachian Tube
Equalises pressure within the middle ear with atmospheric pressure - allowing free movement of the tympanic membrane.
Innervation of the Eustachian Tube
Tympanic plexus - fibres of the glossopharyngeal nerve .
Function of the tensor tympani and stapedius. Loss?
Tensor tympani: Decreases the amplitude of vibrations and tenses the tympanic membrane. Protects the ear from loud noises.
Stapedius: Prevents excessive movement of the stapes and decreases oscillatory range.
Loss of the function of either of these muscles leads to hyperacusis or noise hypersensitivity.
Drainage of Sinuses
Sphenoid sinus –> Sphenoethmoidal recess
Ethmoidal sinus
Anterior –> Hiatus semilunaris –> Middle meatus
Middle –> Ethmoidal bullosa – > Middle meatus
Posterior –> Superior meatus
Maxillary sinus –> Middle meatus
Frontal –> Frontonasal duct –> Hiatus semilunaris – >Middle meatus
Nasolacrimal duct –> Inferior meatus
Innervation of the Sinuses
All are supplied by the Trigeminal nerve
Structure close to the lateral wall of the Ethmoidal Sinus and possible consequences
The orbit lies close to the ethmoidal sinus. Infection may spread to the orbit and optic nerve. The bone is very thin and may easily be fractured, can see intra-orbital bleeding.
Maxillary sinus infection
Greater likelihood due to the maxillary sinuses not being drained by gravity, can lead to accumulation.
Toothache may be seen as the Maxillary sinuses are closely related to the upper molars.
Mastoid air cells: Lining and complications of infection
Lined by squamous non-ciliated epithelial cells.
They may become infected following a middle ear infection, as the infection spreads through the aditus. This can be potentially life threatening as the infection may spread to the brain, resulting in meningitis.
Functions of the Conchae
To create turbulence within inhaled air. Allows the air to the moistened and warmed. Increase surface area.
Functions of the sinus
Lighten the head, add resonance to the voice
Epithelium lining the nasal cavities
Ciliated pseudostratified columnar epithelium with goblet cells.
Sphenoethmoidal recess: Position and function
Found posterior to the superior concha.
The Sphenoid sinus opens into it.
Innervation of the nasal cavity
The nasal cavity is supplied by the trigeminal nerve. The upper portion is supplied by the ophthalmic branch whilst the lower portion is supplied by the maxillary branch.
What passes through the cribiform plate?
The olfactory nerves
Joints found between the ossicles
Synovial
- Prone to Rheumatoid arthritis. Can lead to conductive hearing loss with age
Muscles of the Soft Palate
Palatoglossal arch Palatine tonsils lie between Palatopharyngeus arch Uvula Levitor Veli Palatini Tensor Veli Palatini
3 paired cartilages of the Larynx
Cuneiform, arytenoid and corniculate
Arytenoid movement is permitted by the crico-arytenoid joints.
3 unpaired cartilages of the Larynx
Hyoid, thyroid and cricoid
Laryngeal prominence: Found on the thyroid cartilage. Well-marked in men
Cricoid: Only complete ring of cartilage to encircle any part of the airway
Laryngeal membranes/ligaments
Thyrohyoid, cricothyroid ligament, cricotracheal ligament
Structures of the vocal cords
Rima glottis, vestibular folds (false - no sound production), vocal folds,
Function of the epiglottis
Cartilaginous structure
Prevents aspiration of food into the pulmonary system.
Vertebral levels of the larynx
C3-C6
Cricoid cartilage: C6
Piriform fossa:
Location and possible complications
Location: A recess in the laryngopharynx on either side of the vestibule of the larynx, separated from it by the aryepiglottic folds. (Situated on either side of the larynx inlet)
The internal laryngeal nerve (a continuation of the recurrent laryngeal) lies within, could be damaged when retrieving foreign bodies.
Extrinsic laryngeal muscles
Move the larynx as a whole
Infrahyoid muscles
Suprahyoid muscles
Stylopharyngeus
Intrinsic laryngeal muscles
Alter the length and tension of the vocal cords
Posterior cricoarytenoid: Pulls Cords Apart (PCA)
Lateral cricoarytenoid: Adduction
Cricothyroid:
Thyroarytenoid (vocalis):787
Motor supply of the intrinsic laryngeal muscles
Superior laryngeal nerve (external branch) (CN X)
Cricothyroid muscle
All others
Recurrent laryngeal nerve (superior branch) (CN X)
Sensory supply of the intrinsic laryngeal muscles
Superior laryngeal nerve supplies laryngeal epithelium above the vocal folds
Recurrent laryngeal nerve supplies the epithelium below the vocal folds.
Superior laryngeal nerve
A branch of the vagus nerve (CN X).
Has 2 branches, the internal and external branch.
