Anatomy Topic 3 Case 4 Flashcards
Identify the three parts of the ear
- External ear: auricle / external acoustic meatus
- Middle ear: Tympanic cavity / epitympanic recess
- Internal ear: Bony and membranous labyrinths
Identify 6 features of the auricle
- Helix
- Antihelix
- Tragus
- Antitragus
- Conchae
- Lobule
Identify the arterial supply of the auricle
- Posterior auricular artery
- Anterior auricular branches of temporal and occipital arteries
Identify the lymphatic drainage of the auricle
- Anteriorly: Parotid nodes
- Posteriorly: Mastoid nodes
Identify the innervation of the auricle
- Superficial: Great auricular nerve
- Deep: Vagus nerve and facial nerve
How is the external acoustic meatus formed?
- Lateral third is from the auricular cartilage
- Medial part is from the petrous part of the temporal bone
Describe the course taken by the external acoustic meatus
- Passes upward anteriorly
- Turns upward posteriorly
- Turns downward anteriorly
In what direction should a clinician pull the ear when expecting the external acoustic meatus and tympanic membrane?
- Superiorly
- Posteriorly
- Laterally
Identify the innervation of the external acoustic meatus
- Auriculotemporal branch of the mandibular nerve
- Facial nerve
- Auricular branch of the vagus nerve
Identify 8 features of the tympanic membrane
- Handle of malleus
- Lateral process of malleus
- Umbo
- Anterior malleolar fold
- Posterior malleolar fold
- Pars flaccida
- Pars tensa
- Cone of light
Identify features of the tegmental wall of the middle ear
- Tegmen tympani
Identify features of the jugular wall of the middle ear
- Aperture for tympanic branch of glossopharyngeal nerve
Identify features of the anterior wall of the middle ear
- Opening for pharyngotympanic tube
- Opening for tensor tympani muscle
- Aperture for chorda tympani nerve
Identify features of the mastoid wall of the middle ear
- Aditus to the mastoid antrum
- Pyramidal eminence containing stapedius muscle tendon
- Opening of chorda tympani nerve
Identify features of the membranous wall of the middle ear
- Tympanic membrane
Identify features of the labyrinthine wall of the middle ear
- Promontory and tympanic plexus
- Oval window
- Round window
Where is the mastoid area located and what is its clinical significance?
- Posterior to epitympanic recess
- Contains mastoid air cells
- Which are covered by mucous membrane that is continuous with that throughout the middle ear
- Infections can spread from middle ear to mastoid area, mastoiditis
What is the role of the pharyngotympanic tube?
- Equalises pressure on both sides of the tympanic membrane
Identify the two parts of the pharyngotympanic tube
- Bony part, one third nearest the middle ear
- Cartilaginous part, two-thirds nearest nasopharynx
Identify the arterial supply of the pharyngotympanic tube
- Ascending pharyngeal artery (branch of external carotid artery)
Identify the venous drainage of the pharyngotympanic tube
- Pterygoid plexus
Identify the innervation of the pharyngotympanic tube
- Tympanic plexus from tympanic nerve (branch of glossopharyngeal nerve)
Identify 3 features of the malleus
- Handle, which attaches to tympanic membrane
- Head, which attaches to incus
- Neck, possessing anterior and lateral processes
Identify 3 features of the incus
- Body which attaches to head of malleus
- Long limb which attaches to stapes
- Short limb
Identify 3 features of the stapes
- Head which articulates with incus
- Two limbs
- Base which fits into oval window
Identify the origin, insertion, action and innervation of the tensor tympani
- Origin: Cartilaginous part of eustachian tube, greater wing of sphenoid
- Insertion: Handle of malleus
- Action: Pulls handle of malleus medially, tensing tympanic membrane
- Innervation: Branch from mandibular nerve
Identify the origin, insertion, action and innervation of the stapedius
- Origin: Pyramidal eminence
- Insertion: Neck of stapes
- Action: Pulls stapes posteriorly, preventing excessive oscillation
- Innervation: Branch from facial nerve
Identify the arterial supply of the middle ear
- Tympanic branch of maxillary artery
- Mastoid branch of occipital or posterior auricular arteries
Identify the venous drainage of the middle ear
- Pterygoid plexus
- Superior petrosal sinus
Identify the innervation of the middle ear
- Tympanic plexus from tympanic nerve (branch of glossopharyngeal nerve)
- Tympanic plexus gives off lesser petrosal nerve
Where is the internal ear located?
- Petrous part of temporal bone
- Between middle ear laterally
- And internal acoustic meatus medially
What does the bony labyrinth consist of?
- Vestibule
- Three semicircular canals
- Cochlea
- Perilymph
What does the membranous labyrinth consist of?
- Semicircular ducts
- Cochlear ducts
- Utricle and saccule
- Endolymph
What does the vestibule communicate with?
- Possesses oval window on its lateral wall
- Communicates with semicircular canals posterosuperiorly
- Communicates with cochlea anteriorly
Describe the layout of the semicircular canals
- Three canals: anterior, posterior and lateral
- All at right angles with the other two
- Each canal forms two thirds of a circle connected at both ends to the vestibule
- With one end dilated to form the ampulla
Identify features of the cochlea
- Modiolus (central bony column)
- Cochlear nerve and spinal ganglia
- Cochlear ducts
- Scala vestibuli
- Scala tympani
- Helicotrema (apex)
Where are the otolith organs located and how are they connected?
- Utricle is located posterosuperiorly in the vestibule
- Saccule is located in anteroinferiorly in the vestibule
- Connected by utriculosaccular duct
What is the endolymphatic duct?
- Branch of utriculosaccular duct
- Emerges on posterior surface of petrous part of temporal bone in posterior cranial fossa
- Expands into endolymphatic sac
- Which functions in resorption of endolymph
What are the sense organs in the otolith organs and semicircular canals?
- Otolith organs: maculae
- Semicircular canals: crista
Identify features of the cochlear duct
- Outer wall (spiral ligament)
- Roof (vestibular membrane)
- Floor (basilar membrane)
- Organ of Corti on the basilar membrane
Identify the arterial supply of the inner ear
- Bony labyrinth: Tympanic branch of maxillary artery
- Membranous labyrinth: Labyrinthine artery which divides into cochlear and vestibular vestibular
Identify the arterial supply of the inner ear
- Cochlear and vestibular veins
- Which come together to form labyrinthine vein
Identify the innervation of the middle ear
- Vestibulocochlear nerve divides into vestibular and cochlea nerves
- Facial nerve forms the geniculate ganglion which gives off:
- Greater petrosal nerve
- Nerve to stapedius
- Chorda tympani nerve
Identify the parts of the pharynx
- Nasopharynx (via choanae of nasal cavities)
- Oropharynx (via oropharyngeal isthmus)
- Laryngopharynx (via laryngeal inlet)
Where do the pharyngotympanic tubes open into the pharynx?
- Lateral walls of nasopharynx
How is the pharynx separated form the vertebral column?
- Retropharyngeal space
How does elevation and depression of the soft palate effect the pharynx?
- Elevates to close pharyngeal isthmus and seal off nasopharynx from oropharynx
- Depresses to close oropharyngeal isthmus and seal off oral cavity from oropharynx
Outline the skeletal framework of the C-shaped pharynx
- Medial plate of pterygoid process of sphenoid
- Scaphoid fossa on sphenoid bone
- Petrous part of temporal bone
- Pharyngeal tubercle of occipital bone
Outline the first part of the vertical line of attachment for the lateral pharyngeal walls
- Medial plate of pterygoid process of sphenoid
- Inferiorly onto the pterygoid hamulus
- Descends along pterygomandibular raphe
Outline the second part of the vertical line of attachment for the lateral pharyngeal walls
- Lower aspect of stylohyoid ligament
- Continues onto lesser horn of hyoid
- Turns and runs along upper surface of greater horn of hyoid
Outline the third part of the vertical line of attachment for the lateral pharyngeal walls
- Superior tubercle of thyroid cartilage
- Descends along oblique line to inferior tubercle
- Continues over cricothyroid muscle to cricoid cartilage
Identify the origin, insertion, action and innervation of the superior constrictor
- Origin: Pharyngeal raphe
- Insertion: Pterygomandibular raphe
- Action: Constriction of pharynx
- Innervation: Pharyngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the middle constrictor
- Origin: Pharyngeal raphe
- Insertion: Greater and lesser horns of hyoid bone, and stylohyoid ligament
- Action: Constriction of pharynx
- Innervation: Pharyngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the inferior constrictor
- Origin: Pharyngeal raphe
- Insertion: Cricoid cartilage and oblique line of thyroid cartilage
- Action: Constriction of pharynx
- Innervation: External branch of superior laryngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the stylopharyngeus
- Origin: Medial side of base of styloid process
- Insertion: Pharyngeal wall
- Action: Elevation of pharynx
- Innervation: Glossopharyngeal nerve
Identify the origin, insertion, action and innervation of the salpingopharyngeus
- Origin: Inferior aspect of pharyngotympanic tube
- Insertion: Pharyngeal wall
- Action: Elevation of pharynx
- Innervation: Vagus nerve
Identify the origin, insertion, action and innervation of the palatopharyngeus
- Origin: Upper surface of palatine aponeurosis
- Insertion: Pharyngeal wall
- Action: Elevation of pharynx
- Innervation: Vagus nerve
What does the buccopharyngeal fascia cover?
- Outside of the muscular part of the wall
- It is a component of the pretracheal layer of cervical fascia
What does the pharyngobasilar fascia?
- Lines the inner surface of the wall
What does the oropharyngeal triangle enable?
- Stylopharyngeus to slip into the pharyngeal wall
- Muscles, nerves and vessels to pass between regions lateral to the pharyngeal wall and oral cavity, particularly the tongue
Outline the arterial supply of the pharynx
- Ascending pharyngeal artery
- Ascending palatine branch of the facial artery
- Tonsilar branches of the facial artery
- All of which arise from the external
Outline the venous drainage of the pharynx
- Pterygoid plexus
Outline the lymphatic drainage of the pharynx
- Retropharyngeal nodes
- Paratracheal nodes
- Infrahyoid nodes
Outline the innervation of the pharynx
- Muscles are innervated by vagus except stylopharyngeus which is innervated by glossopharyngeal
- Nasopharynx is innervated by maxillary nerve
- Oropharynx is innervated by glossopharyngeal nerve
- Laryngopharynx is innervated by vagus nerve
Where are the pharyngeal tonsils located?
- Midline of the roof of the nasopharynx
Where are the palatine tonsils located?
- Between palatoglossal and palatopharyngeal arches
Where are the lingual tonsils located?
- Posterior third of the tongue
Outline the arterial supply of the tonsils
- Tonsillar branch of facial artery
Outline the lymphatic drainage of the tonsils
- Jugodigastric nodes
Identify the two functions of the larynx
- Sphincter to close respiratory tract
- Produce sound
At which vertebral level is the cricoid cartilage located?
- C6
Identify features of the cricoid cartilage
- Lamina
- Arches
- Facet for articulation with arytenoid cartilage
- Facet for articulation with inferior horn of thyroid cartilage
At which vertebral level is the thyroid cartilage located?
- C4/C5
Identify features of the thyroid cartilage
- Superior horns
- Laminae
- Laryngeal prominence
- Superior thyroid notch
- Inferior thyroid notch
- Inferior thyroid tubercle
- Oblique line
- Inferior horns
Identify features of the epiglottis cartilage
- Epiglottic tubercle
Identify features of the arytenoid cartilage
- Apex
- Base
- Medial surface
- Anterolateral surface
- Vocal process
Outline the attachments of the thyrohyoid membrane?
- Runs between superior margin of thyroid laminae and greater horns of the body of the hyoid bone
Outline the attachments of the hyo-epiglottic membrane?
- Runs between midline of epiglottis to body of hyoid bone
Outline the attachments of the cricotracheal membrane
- Runs between lower body of cricoid cartilage and upper border of first tracheal cartilage
Outline the attachments of the cricothyroid ligament
- Arch of cricoid cartilage, extends superiorly, attaching
- Anteriorly: Thyroid cartilage
- Posteriorly: Vocal processes of arytenoid cartilage
What are the vocal ligaments?
- Free margin of cricothyroid ligament
- Between thyroid cartilage and vocal processes of arytenoid cartilage
- Which is thickened to form vocal ligament
- Under the vocal fold
-
Outline the attachments of the quadrangular membrane
- Between lateral margins of epiglottis and the anterolateral surface of the arytenoid cartilage
What are the vestibular ligaments?
- Free margin of the quadrangular membrane
- Which is thickened to form vestibular ligament
- Under the vestibular fold
-
What is the vestibule of the larynx?
- Upper chamber between laryngeal inlet and the vestibular folds
What is the middle chamber of the larynx?
- Chamber between vestibular folds above and vocal folds below
What is the infraglottic space of the larynx?
- Space between the vocal folds and inferior opening of larynx
What is the laryngeal ventricle?
- Trough shaped space on each side
- Between mucosa of middle cavity
What is the laryngeal saccule?
- Elongated tubular extension of each ventricle which projects anterosuperiorly between the vestibular fold and thyroid cartilage.
What is the rima vestibuli?
- Triangular opening that occurs between the two adjacent vestibular folds at the entrance to the middle chamber of the laryngeal cavity
What is the rima glottidis?
- Narrow triangular opening that occurs between the two vocal folds
Identify the origin, insertion, action and innervation of the cricothyroid muscle?
- Origin: Anterolateral aspect of arch of cricoid cartilage
- Insertion: Inferior of thyroid cartilage
- Action: Lengthens vocal folds (raising pitch of voice)
- Innervation: Superior laryngeal nerve (from vagus nerve)
Identify the origin, insertion, action and innervation of the transverse arytenoid?
- Origin: Posterior surface of arytenoid cartilage
- Insertion: Posterior surface of opposite arytenoid cartilage
- Action: Closes rima glottidis by adduction of arytenoid cartilage
- Innervation: Recurrent laryngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the oblique arytenoid?
- Origin: Muscular processes of arytenoid cartilage
- Insertion: Apex of adjacent arytenoid cartilage
- Action: Closes rima glottidis by adduction of arytenoid cartilage
- Innervation: Recurrent laryngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the posterior cricoarytenoid?
- Origin: Posterior surface of lamina of cricoid cartilage
- Insertion: Posterior surface of muscular processes of arytenoid cartilage
- Action: Opens the rima glottidis by abduction of arytenoid
- Innervation: Recurrent laryngeal branch of vagus nerve
Identify the origin, insertion, action and innervation of the aryepiglottic muscle?
- Origin: Apex of arytenoid
- Insertion: Lateral surface of arytenoid
- Action: Closes the laryngeal inlet
- Innervation: Recurrent laryngeal branch of vagus nerve
Outline the arterial supply of the larynx
- Superior laryngeal artery
- Inferior laryngeal artery
- Branches of the superior thyroid artery from external carotid artery
Outline the venous drainage of the larynx
- Superior laryngeal veins
- Inferior laryngeal veins
Outline the lymphatic drainage of the larynx
- Deep cervical nodes
Outline the innervation of the larynx
- Superior laryngeal nerve supplying cricothyroid muscle and sensory innervation above vocal folds
- Recurrent laryngeal nerve, sensory innervation below the vocal folds and all other muscles
Outline the four suprahyoid muscles
- Stylohyoid
- Digastric
- Mylohyoid
- Geniohyoid
What is the function of the suprahyoid muscles?
- Pull hyoid bone upwards
- To elevate the larynx during swallowing
Outline the four infrahyoid muscles
- Sternohyoid
- Omohyoid
- Thyrohyoid
- Sternothyroid
What is the function of the infrahyoid muscles?
- Pull hyoid bone downwards
- To depress the larynx during swallowing
What does the chorda tympani innervate?
- Taste to anterior 2/3 of the tongue
What does the greater petrosal nerve innervate?
- Lacrimal gland
- Mucous glands of nasal cavity
- Maxillary sinus
How many turns does the cochlea take?
-2.75
Where is the vestibular membrane located and what is its role?
- Roof of cochlear duct between it and the scala vestibuli
- Separates endolymph of cochlear duct from perilymph of scala vestibuli
Where is the basilar membrane located and what is its role?
- Floor of cochlear duct between it and the scala tympani
- Separates endolymph of cochlear duct from perilymph of scala tympani
- Houses Organ of Corti
Where is the stria vascularis located and what is its role?
- Located on outer wall of cochlear duct
- Produces endolymph
Where is the spiral ligament located?
- Outer wall of cochlear duct (base of cochlear duct)
Where is the spiral lamina located?
- Inner wall of cochlear duct (apex of cochlear duct)
The labyrinthine artery is a branch of which artery? What does it supply?
- Basilar artery
- Membranous labyrinths
