Special Senses: Auditory & Vestibular Apparatus Flashcards
Collects sounds. Shell like part. Consists of single elastic cartilage w/c is continuous with cartilage of external acoustic meatus. Contains hair, sweat/sebaceous glands. Shape varies.
Auricle
External ear is composed of
External auditory meatus & Auricle
No cartilage. Can be pierced for earring.
Lobule
Auditory passage. Extends from concha to tympanic membrane. S shaped.
External acoustic meatus
Length of External acoustic meatus
2.5cm long
External acoustic meatus composition: Lateral 1/3 is _________ & Medial 2/3 __________.
Cartilage. Bony.
External acoustic meatus in infants
Pure cartilage
Part of EAM lined w/ skin. Contents are hair follicles, sebaceous gland & ceruminou gland.
Lateral part
Part of EAM lined with thin skin, composed of Isthmus.
Medial part
Ceruminous gland produces
Cerumen
Constricted medial part of the EAM
Isthmus
Arterial supply of the EAM
Post auricular branch of external carotid artery, Deep auricular branch of maxillary artery & Auricular branch of superficial temporal artery “PDA”
Venous drainage of the EAM
Pterygoid plexus, EJV & Maxillary vein “PEM”
Nerve supply of the EAM
Auriculotemporal nerve, Tympanic plexus & Auricular branch “ATA”
Auriculotemporal nerve is from what CN
CN V
Tympanic plexus is from what CN
CN VII
Auricular branch nerve is from what CN
CN X
Thin, semitransparent & oval membrane. Medial end of EAM. Separates external from middle ear. Oblique and slopes inferomedially. Pearly gray and shiny.
Tympanic membrane
In Tympanic membrane: concavity toward the. Eatus with a central depression, ________, formed by handle of malleus.
Umbo
In Tympanic membrane: from umbo, bright area emanates called
Cone of light
In Tympanic membrane: moves in response to air vibration that pass to it. Vibrations are transmitted from TM by ________ through the middle ear to inner ear.
Auditory ossicles
Arterial supply of the tympanic membrane
Maxillary artery, Deep auricular artery, Posterior auricular artery & Tympanic branch “M DPT”
Venous drainage of the tympanic membrane
EJV
Nerve supply of the tympanic membrane
Auriculotemporal nerve
Foreign bodies, infection & excessive pressure as in scuba diving.
Deafness
Narrow cavity in petrous temporal bone. Contents are auditory ossicles, stapedius, tensor tympani & chorda tympani.
Middle ear
Anterior to middle ear
Nasopharynx
Posterosuperior to middle ear
Mastoid antrum
Walls of the Middle Ear: formed by tegmen tympani. Separates ME from dura.
Roof or Tegmental
Walls of the Middle Ear: formed by the bone. Separates ME from IJV.
Floor or Jugular
Walls of the Middle Ear: formed by tympanic membrane
Lateral or Membranous
Walls of the Middle Ear: composed of semicircular ducts & cochlea. Separates ME from inner ear.
Medial or Labyrinthine
Small window of Labyrinthine: closes the base of stapes. Vibration of stapes are transmitted to the inner ear.
Fenestra vestibuli
Small window of Labyrinthine: closed by a secondary TM. Allows perilymph to move in response to impulses.
Fenestra cochlea
Walls of the Middle Ear: leads to mastoid antrum via an opening, ________. Pyramidal eminence contains stapedius mucle.
Posterior or Mastoid. Aditus.