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Gisselle Reyes, Period 5,Integumentary system - Coggle Diagram
Gisselle Reyes, Period 5,Integumentary system
Functions of the skin
Protection: contains three barriers
- Chemical barrier: skin secretes sweat, and sebum
- Physical barrier: flat, dead keratinized cells of stratum corneum block most water and water soluble substances
- Biological barrier: epidermis contains phagocytic cells and dermis contains macrophages
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cutaneous sensations: receptors part of the nervous system that respond to stimuli outside of the body like touch.
Metabolic functions: skin can synthesize vitamin D, keratinocytes can activate some hormones
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Layers of the skin
**Epidermis: superficial layer of the skin: composed of keratinized stratified squamous epithelium
- Cells
- Keratinocytes: produce keratin.
- Melanocytes: produce melanin
- Dendritic: key activator in immune system
- Tactile: sensory receptors that sense touch
- Layer of epidermis
- Stratum basale: deepest layer, cells actively mitotic
- stratum spinosum: Keratinocytes in this layer paper spikey
- stratum granulosum; keratinization begins, shows water loss
- stratum lucidum: found only in thick skin
- stratum corneum: superficial layer; protect deeper cells, prevent water loss, protect from abrasion and penetration
**Dermis: middle layer of skin: mostly fibrous connective tissue
- Papillary layer: helps with temperature regulation and contain the dermal papillae which sends fingerlike projections to the epidermis.
- Reticular layer: consist of dense fibrous connective tissue. it supports the skin and the fibers allows strength and elasticity. Contains collagen and elastic fibers.
**Hypodermis: support tissue and consist of adipose and loose connective tissue: anchors skin to underlying structures
Accessory organs
**Hair: dead keratinized cells that protects from heat loss and sunlight. it warns of insects of skin
- Hair follicle: helps with growth and the receptors have nerve endings that help with sensory function.
- Hair root: within the scalp and keratinization is incomplete
- Hair shaft: above the scalp, keratinization is complete
- Medulla: central core of large cells and air spaces
- cortex: several layers of flattened cells surrounding Medulla
- cuticle: outer layer consisting of overlapping layers of single cells
- Hair structures
- Hair papilla: capillaries that supplies nutrients to growing hair
- hair matrix: produces hair cells
- Arrector pili: causes goosebumps
**Nails: on epidermis that contain hard keratin.
- nail parts:
- nails bed: under nail plate
- nail matrix: nail growth
- nail folds: overlap border of nail
- eponchium (cuticle)
- lunule: thicken nail matrix
- free edge of nail
- nail plate: keratin plate
- root of nail; embedded in nail
**Sweat glands (sudoriferous)
- Eccrine (merocrine glands): most numerous and mostly on palms, soles, and forehead. They have thermoregulation function and secrete sweat. Ducts connect to pores
- Apocrine glands: secretes yellowish sweat that contains proteins and fatty substances. Mostly on axillary and genital areas.
- ceruminous glands: located in external er secretes cerumen (ear wax)
- sebaceous glands: secrete sebum, most develop from hair follicles and secrete into hair follicles
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Disorders
- Chicken Pox: Viral infection that causes blistering
- Acne: clogged pores by dirt or over production of skin oils
- Psoriasis: skin inflammation caused by antoimmune disease
- Staph infection: Bacterial infection by staphylococcus
- fungal infections: collection of diseases caused by fungi