The tympanic cavity, which originates in the endoderm, is derived from the first pharyngeal pouch (Figs. 16.2 and 16.7). This pouch expands in a lateral direction and comes in contact with the floor of the first pharyngeal cleft. The distal part of the pouch, the tubotympanic recess, widens and gives rise to the primitive tympanic cavity, and the proximal part remains narrow and forms the auditory tube (eustachian tube; Fig. 16.7B and 16.8), through which the tympanic cavity communicates with the nasopharynx.
Walls of central portion of outpocketing are apposed
Was this article helpful?
The best start to preventing hair loss is understanding the basics of hair what it is, how it grows, what system malfunctions can cause it to stop growing. And this ebook will cover the bases for you. Note that the contents here are not presented from a medical practitioner, and that any and all dietary and medical planning should be made under the guidance of your own medical and health practitioners. This content only presents overviews of hair loss prevention research for educational purposes and does not replace medical advice from a professional physician.