integument system Flashcards
what is the integument system consist of?
cutaneous membrane(skin) +accessory structures
what are the functions of the system?
protection (forms barrier, immune response, prevents water loss), thermoregulation, sensation, storage, vitamin D synthesis, excretion
what are the three layers of integument?
epidermis, dermis, hypodermis
what are the three main cell types?
keratinocytes, melanocytyes, dendrtic cells
what are keratinocytes?
produce keratin, 30-40 day turnover, superficial cells are dead
what are the melanocytes?
produce pigment melanin, protects against UV radiation, creates tan
what are dendritic cells?
immune function, macrophages patrol the skin, protect against pathogens/ cancer
4-5 layers of the epidermis?
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
what is the corneum layer?
up to 30 layers of dead keratinocytes, cell filled with keratin, protective (cells continually shed), may contain carotene
what is the lucidum layer?
few layers of thin, flat, dead keratinocytes, found only in thick skin, plantar and palmer regions
what is the granulosum layer?
keritinization begins here, keratohyalin granules, glycolipid granules secrete into ECF and prevent water loss,
what is the spinosum layer?
8-10 layers of tightly joined living keratinocytes, desmosomes, dendritic cells here
what is the basale layer?
single layer of keritinocytes and melanocytes, access to underlying c.t and mitosis, cell growth/replacement produced here
characteristics of the dermis layer?
2nd layer of skin, blood vessels/nerves here, thick layer of c.t, cells=fibroblasts and immune cells, various sensory receptors
what two layer is the dermis consist of?
papillary and reticular layer
what is the papillary layer?
top 20%. of dermis, tissue=loose areolar, forms papillae and epidermal ridges, detect light touch
what is the reticular layer?
bottom 80% of dermis, tissue is dense irregular, thick network of collagen and elastic fibres, strength/attachement to underlying structures, lamelleted corpuscles detect pressure/ vibration
what is the hypodermis?
not a layer of the skin, subcutaneous layer of integument, tissue=adipose and areolar, insulation and lipid storage, flexible
what are the two types of exocrine glands in skin?
sebaceous and sweat
what is the sebaceous gland?
produce sebum(oily secretion), associated with hair follicles, most active during puberty and fetal development, holocrine gland
what are the two types of sweat glands?
eccrine, over body surface in palmer/planter regions, secret sensible perspiration to cool body, apocrine, hair follicles in axillary and anogenital regions, secrete fats, secreted in response to fear/ arrousal
what is the function of hair?
insulation, sensation, protection
what are the two types of hair?
vellus(fine body hair) terminal (course body hair)
