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.
Quick Answer. Possible causes of swollen lymph nodes behind the ears include an ear infection, an abscessed tooth, a cold, the flu or another infection, according to MedlinePlus. Lymph nodes also commonly appear beneath the jaw, on the back of the head, or on the neck, armpit or groin.
Ear congestion typically occurs when the Eustachian tube, located between the ear and throat, becomes blocked. A variety of medical conditions (allergies, viruses, colds and upper respiratory infections) can cause fluid to collect in the Eustachian tube and/or middle ear, leading to congested ears. Ear congestion symptoms may include: muffled hearing, pain, inflammation, discharge, swelling and/or itching.