False. The structure that allows equalization of the pressure in the middle ear with that outside the body is the Eustachian tube. The external auditory meatus, also known as the ear canal, is a passage that leads to the middle ear. It is responsible for transmitting sound waves from the outer ear to the eardrum. However, it does not play a role in equalizing pressure in the middle ear. The Eustachian tube, on the other hand, is a small tube that connects the middle ear to the back of the throat. It helps regulate pressure in the middle ear by opening and closing to allow air to enter or exit the middle ear. This process is important for maintaining optimal hearing and preventing discomfort or pain in the ears due to changes in air pressure.
b. False
The structure that allows equalization of pressure in the middle ear with that outside the body is not the external auditory meatus, but rather the Eustachian tube (also known as the auditory tube or pharyngotympanic tube). The Eustachian tube connects the middle ear to the nasopharynx, which is the upper part of the throat behind the nose. This tube helps to maintain equal air pressure on both sides of the eardrum, which is crucial for normal hearing and preventing damage to the ear. The external auditory meatus, on the other hand, is the outer portion of the ear canal that leads from the outer ear to the eardrum. While it does play a role in conducting sound to the eardrum, it is not involved in pressure equalization.