ENT Anatomy Flashcards
External Ear:
What type of cartilage is present?
Elastic Cartilage
External Ear:
Innervation
- Greater auricular nerve
(branch of cervical plexus) - Lesser occipital nerve
(branch of cervical plexus) - Auriculotemporal nerve
(branch of mandibular nerve) - branches of Facial and Vagus nerve
External Ear:
Lymphatic drainage
Lateral surface of the superior half of the auricle drains to the:
- Superficial Parotid Lymph nodes
Cranial surface of the superior half of the auricle drains to the:
- Mastoid Lymph nodes
- Deep Cervical Lymph nodes
Remainder of the auricle, including the lobule, drains into:
- Superficial Cervical Lymph nodes
External Acoustic Meatus:
Name 4 features that help protect the auditory canal
Hair
Cerumen
Curvature and Shape
Tightness of skin
Which direction should you pull the auricle if examining the ear with an otoscope in an adult vs. child?
Adults:
- pull auricle gently upward and backward
Children:
- downward and backward
Middle Ear:
What foramen leads to middle cavity from the cranial cavity?
Internal Acoustic Meatus
Middle Ear:
Which bone is the Internal Acoustic Meatus foramen in?
Petrous part of the Temporal bone
Middle Ear:
Which nerves pass through the Internal Acoustic Meatus foramen?
Facial (VII)
Vestibulocochlear (VIII)
Middle Ear:
Where is the Facial nerve travelling to and what does it innervate?
- closely associated with the Vestibulocochlear nerve in the Internal Acoustic Meatus
- after exiting IAM, the facial nerve continues its course through the Facial canal within the Temporal bone
- eventually exiting the Skull via the Stylomastoid foramen
- innervates muscles of facial expression and carries taste sensation from anterior 2/3s of the tongue
Middle Ear:
What is the Vestibulocochlear nerve responsible for?
Where is the nerve travelling to and what does it innervate?
- responsible for transmitting sensory information related to balance (vestibular) and hearing (cochlear)
- after exiting IAM, the Vestibulocochlear nerve splits into 2 branches
- Vestibular nerve innervates the vestibular apparatus (in the inner ear)
- Cochlear nerve innervates the cochlea (organ of hearing)
Tympanic Membrane:
What are the identifying features that can help orientate the image?
- Malleolar folds are superior
- umbo is inferior
Tympanic Membrane:
Name 5 features of Otitis Media (glue ear)
- opaque/cloudy appearance
- tympanic membrane may bulge outward
- presence of fluid behind membrane can restrict its movement, leading to reduced mobility or immobility
- fluid may be visible
- yellowish/amber colour
Tympanic Membrane:
Where is the safest to make incisions in the Tympanic membrane?
Either:
- anteroinferior quadrant
Or
- posteroinferior quadrant
Ossicles:
Function
Play a crucial role in the:
transmission, amplification, and protection of sound signals
(as the signals travel from the external environment to the inner ear, where they are processed and interpreted as auditory sensations)
Ossicles:
Which 2 small muscles attach to the ossicles?
Tensor Tympani
Strapedius Muscle