Flashcards in Unit VIII - Ear Pt. 1 Deck (66)
What is the embryologic structure of ectodermal thickening on the lateral "head" that gives rise to the ears?
What is the pathway of the embryological formation of the ear?
Placode --> auditory pit --> auditory vesicle --> most of membranous inner ear
What structures of the ear are derived from the first pharyngeal pouch?
Auditory tube and tympanic cavity
From where is the malleus derived?
Dorsal end of the ventral mandibular cartilage
From where does the incus arise?
Dorsal end of the first pharyngeal arch
What ear structure is derived from the dorsal end of the second pharyngeal arch?
From where does the tympanic membrane develop?
From where does the external acoustic canal develop?
First pharyngeal groove
From where does the auricle develop?
A groove next to the first pharyngeal groove
What are the three portions of the ear?
External, middle, and inner
What is another name for the auricle?
What tissue makes up the auricle?
What is the function of the auricle?
Funnel sound waves into the external acoustic meatus
What are the three extrinsic ear muscles that position the auricle?
Anterior, superior, and posterior auricular muscles
Which auricular muscle inserts on the front of the helix?
Anterior auricular muscle
Which auricular muscle is the largest?
Superior auricular muscle
Where does the superior auricular muscle insert?
On superior side of auricle
What is the smallest auricular muscle?
Anterior auricular muscle
Where does the posterior auricular muscle insert?
Lower, posterior aspect of concha
What are the intrinsic ear muscles?
Helicis major and minor, tragicus, antitragicus, transverse muscles of the auricle, oblique muscles of the auricle
About how long is the external acoustic meatus?
What shape is the external acoustic meatus?
What part of the external acoustic meatus is within a bone? Which bone?
Medial 2/3; temporal bone
What covers the entire length of the external acoustic meatus?
Skin with modified sweat glands
What do the modified sweat glands of the external acoustic meatus produce?
Where does the external acoustic meatus terminate?
What motion makes otoscopic examination possible even though the length of the external acoustic meatus is not straight?
Gently pulling out, down, and forward on the lobule
What makes up the blood supply to the external ear?
Posterior auricular branch of external carotid artery
Anterior auricular branch of superficial temporal artery
Auricular branch from the occipital artery
What makes up the sensory supply to the external ear?
Auriculotemporal nerve of the mandibular division of trigeminal
Auricular branch of vagus
Great auricular nerve (C2 and C3)