The tissue lining the inside wall is a moist and folded layer of mucous membrane.
The channel of the tube is lined with a layer of mucous membrane that has many folds and papillae small cone-shaped projections of tissue.
Particles deposited on the remaining portion of the nasal cavity and on the pharynx are removed by tiny hairs, called cilia, on the surface of these two regions, which beat almost continuously to move a covering layer of mucous toward the throat (mucociliary apparatus).
"We know crab gills are coated with a thin layer of mucous," Watts told The Huffington Post in an email.
Peripheral layer of mucous extracellular matrix was compacted and was common for the entire cluster.
Uninjured epithelium consisted of an outer apical layer of epithelial cells, an interstitial layer of mucous secreting Leydig cells interspersed with keratinocytes, and a basal layer of germinative basal keratinocytes (Fox, 1986; Kelly, 1966).
One of the first obstacles faced by Salmonella is a thick layer of mucous that covers the surface of the gut epithelium and provides an initial barrier, which must be penetrated in order to gain direct contact with the epithelium.
The accessory nidamental gland, present in all demersal decapodiform females, secretes an additional layer of mucous on eggs prior to their attachment to the benthic substrate (e.g. [ 32, 66- 68]).
The tear film has traditionally been considered to consist of three distinct layers: a thin outer lipid layer that is secreted by the meibomian glands, an inner layer of mucous secreted by goblet cells of the conjunctiva, and a complex middle aqueous layer secreted by the main lacrimal and accessory gland that contains a wide array of dissolved substances.
The endocervical mucosa is about 3 mm thick, lined with a single layer of columnar mucous cells, and contains numerous tubular mucous glands which empty viscous alkaline mucus into the lumen.
