What is the pharyngotympanic tube and what is its purpose?
What will be an ideal response
The pharyngotympanic tube links the middle ear cavity with the nasopharynx. Normally it is flattened and closed, but swallowing or yawning opens it briefly to equalize pressure in the middle ear cavity with external air pressure.
You might also like to view...
The hyperpolarization that occurs at the end of an action potential is due to the prolonged
A. open state of chemically gated sodium channels. B. open state of voltage-gated sodium channels. C. closure of chemically gated sodium channels. D. closure of voltage-gated potassium channels. E. open state of voltage-gated potassium channels.
Drugs that mimic the action of norepinephrine are likely to affect ________
A) the parasympathetic division of the ANS B) both the sympathetic and parasympathetic divisions of the ANS C) the sympathetic division of the ANS
By volume, most of the semen is produced in the ________
A) bulbourethral glands B) prostate gland C) testes D) penis E) seminal vesicles
________ and respiratory movements move lymph upward through lymphatic vessels and trunks below the heart.
A. Heart contractions B. Osmotic pressure C. Skeletal muscle contractions D. Movement of internal organs