BIOL 204 Lecture Notes - Lecture 14: Ostracoderm, Basement Membrane, Monotreme
Document Summary
Slime glands in myxinoidea: multicellular slime glands, rapidly release a stream of mucins and protein threads, rapidly expands in seawater to produce a thick mucus slime that coats the gills of a potential predator. Epidermal glands: amphibians: most epidermal glands are multicellular, amphibians have, abundant multicellular mucus glands to produce the mucus cuticle, multicellular granular glands (poison glands) for defense. In larvae- unicellular leydig cells produce antiviral and antibacterial substances. In birds; uropygial gland secretes oil transferred to feathers during preening. In monotremata; they open directly to the surface while in eutherian and metatheria, many glands release their secretions together through a nipple or teat. Dermis and hypodermis: the dermis contains; connective tissue, blood vessels lymphatic vessels, nerves, pigment cells. In teleostomi mesenchyme of the dermis can give rise to dermal bone: sometimes adheres closely to the underlying muscle, but in many taxa is separated by a layer of loose connective tissue and adipose tissue; hypodermis.
