Second Messengers

question 50

Multiple Choice

Second messengers

• A) are activated by thyroid and steroid hormones
• B) are generated by enzymes called kinases
• C) often initiate cascades of protein phosphorylations
• D) are broken down by enzymes called phosphorylases

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Definitions:

Oval Window

A membrane-covered opening that leads from the middle ear to the cochlea in the inner ear, vital for the process of hearing.

Ossicles

The three small bones located in the middle ear, named the malleus, incus, and stapes, that play a key role in transmitting sound vibrations to the inner ear.

Middle Ear

The portion of the ear containing the ossicles, which connect the eardrum to the oval window and amplify sound waves.

Cochlea

The fluid-filled, snail-shaped, bony chamber in the inner ear that contains the basilar membrane and its hair cells (the sound receptors).