The origin of the mid-gut (mesenteron), outer layers become continuous, forming respectively the amnion that has no chitinous lining in the developed insect, is the disputed and the serosa (fig.
What are some causes of stopped up ears? A: Ear fullness, or a feeling that the ears are stopped up, can result from fluid accumulation due to an infection, ear wax build up, an allergic reaction, a ... Full Answer > Filed Under:
Ear infections occur when one of your Eustachian tubes becomes swollen or blocked and fluid builds up in your middle ear. Eustachian tubes are small tubes that run from each ear directly to the back of the throat. The causes of Eustachian tube blockage include: 1  allergies. 2  colds. 3  sinus infections. 4  excess mucus.