ear ossicles

The distinction is made clear by examples such as the ear ossicles of mammals.

The ear ossicles in mammals are former bones of the lower jaw.

Thus the mammalian ear ossicles were once bones in the jaw of early proto-mammals, the Therapsida.

The ear ossicles are homologous with the jaw bones and the gill covers, but not analogous.

Freezing caused the brain of the man to be slightly swollen, and his inner ear ossicles were lost during preparation of the slices.

Air pressure changes in the ear canal cause the vibrations of the tympanic membrane and middle ear ossicles.

Encased within the temporal bones are the six 'ear ossicles' of the middle ears, though these are not part of the skull.

This cholesteatoma, in turn, can erode the middle ear ossicles, facial nerve, inner ear and even involve the brain.

Around day 30 of gestation, the endoderm-lined first expands to form the tympanic cavity, which subsequently envelops the inner ear ossicles.

The three small bones that are responsible for this complex process are the malleus, the incus, and the stapes, collectively known as the ear ossicles.

The dimensions of the articulating ear ossicles lead to an increase in the force applied to the stapes footplate compared with that applied to the malleus.

Then the middle ear ossicles transfer mechanical energy to the cochlea by way of the stapes footplate hammering against the oval window of the cochlea.

Type 2 involves repair of the tympanic membrane and middle ear in spite of slight defects in the middle ear ossicles.

One of his major discoveries was the homology of the opercular plates of the gill cover of fishes with the inner ear ossicles of mammals.

"Abstract: The densities of middle ear ossicles of golden moles (family Chrysochloridae, order Afrosoricida) were measured using the buoyancy method.

The jaw however, based on Haramiyavia, is less derived; "at the level of evolution of Morganucodon and Kuehneotherium, with a groove for ear ossicles on the dentary".

It is a general rule that any adaptations which are no longer useful either become vestigial organs (see vermiform appendix), or may be selected and adapted to other functions (see ear ossicles).

When tensed, the action of the muscle is to pull the malleus medially, tensing the tympanic membrane, damping vibration in the ear ossicles and thereby reducing the amplitude of sounds.

The tympanic membrane is superiorly related to middle cranial fossa, posteriorly to the ear ossicles and the facial nerve, inferiorly to the parotid gland and anteriorly to the temporomandibular joint.

The ear ossicles are pachyosteosclerotic (dense and compact) in cetaceans and very different in shape compared to land mammals (other aquatic mammals, such as sirenians and earless seals, have also lost their pinnae).

The Woodland jumping mouse was originally classified as Zapus insignis in 1891, but differences detected in dental morphology, ear ossicles, and the baculum resulted in the creation of two new genera, Napaeozapus and Euzapus.

Furthermore, the primitive jaw joint between the articular and quadrate bones, which in modern mammals has moved into the middle ear and become part of the ear ossicles as malleus and incus, is still to be found in Morganucodon.

Another example is the long journey of the mammalian ear ossicles, which started in the gill covers of ancient fish, then became part of the lower jaw of reptiles, and then became part of the inner ear of mammals.

Like Erik Jarvik, he has argued that the three ear ossicles of mammals can be derived from components of the hyoid branchial arch of osteolepiforms rather than from both the mandibular and hyoid arches as claimed by the Reichert-Gaupp theory.

The classic example is the ear ossicles of mammals, which we know from palaeontological and embrological studies originated in the upper and lower jaws and the hyoid of their Synapsid ancestors, and further back still were part of the gill arches of early fish.