Ossicles

size of stapes

3.5 mm long

incus size

7 mm long

size of malleus

8-9 mm long

incudostapedial joint of incus

connection and point of connection with the stapes (articulation of incus and stapes)

head of stapes

connects with lenticular process of incus

head of malleus

connects with the body of the next middle ear ossicle; the incus

short process of incus

projets posteriorly

lenticular process of incus

short process projects posteriorly while long process bends medially, forming lenticular process

4 parts of incus

short process, long process, lenticular process, incudostapedial joint

stapes

smallest bone in body

ossicles

smallest bones int eh body; at adult size at birth

two ways the middle ear overcome impedance mismatch

the area of the tympanic membrane is longer than that of the stapes footplate in the cochlea, so the pressure is concentrated over a smaller area and because of the lever action of the middle ear bones (arm of incus is shorter than that of malleus, producing a lever action that increases the force and decreases the velocity of the stapes)

lateral process of malleus

what produces the bulge on the eardrum when we look otoscopically

oval window

where footplate of stapes is embedded

long process of incus

bends medially

neck of stapes

bicurates to the become the crusa

promontory

bulge created by the basal turn of the cochlea

malleus

connected to tympanic membrane and incus

manubrium of malleus

firmly embedded between the fibrous and mucous membrane layers of the tympanic membrane; most lateral attachment of the ossicular chain

5 parts of stapes

head, neck, anterior crux, posterior crux, footplate

incus

intermediate communicating link for the ossicular chain

footplate of stapes

makes contact with the oval window of the inner ear; embedded into the oval window by the annular ligament; most medial attachment of the ossicular chain

4 parts of malleus

manubrium, lateral process, neck, head

neck of malleus

narrowing between its manubrium and head

round window

opening sealed by the second tympanic membrane and marks the entrance into the scala tympani for the cochlea