ZOO 3000 Lecture Notes - Lecture 16: Homeostasis, Apocrine, Dermis
27 Jul 2018
School
Department
Course
Professor
Document Summary
Such as nails, claws, hair, glands, scales and feathers. Skin has 2 layers: epidermis stratified epithelium, dermis loose and dense connective tissue, hypodermis the lowermost layer of the integumentary system directly below the dermis. Functions produce keratins, formation of the epidermal water barrier: melanocytes, produce melanin from tyrosine via the enzyme tyrosinase, pigment transfer to keratinocytes pigment donation. Functions melanin protects dna fro(cid:373) the su(cid:374)"s har(cid:373)ful uv radiatio(cid:374: la(cid:374)gerha(cid:374)s" cells, part of mononuclear phagocyte system, characteristic indented nucleus and rod-shaped bodies. Functions protects against infection, antigen-presenting immune cells, involved in delayed- type hypersensitivity reactions (i. e. skin allergic responses: merkel"s cells, characterized by dense neurosecretory granules, close association with afferent sensory nerve terminals. F"17: keratinhyalin granules containing proteins that promote aggregation of keratin in the cytoplasm (i. e. keratinization) Lamellar bodies contain lipid mixture that contribute to epidermal water barrier between. Sgr and sc: stratum corneum (sc, anucleate cells, packed with keratin filaments cornified. Dermis: composed of 2 distinct layers, papillary layer.
