Term
| What are the 3 layers of the skin? |
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Definition
| epidermis, dermis, subcutaneous |
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Term
| What is the epidermis composed of? |
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Definition
| it is keratinized, composed of stratified squamous epithelium, keratinocytes, melanocytes, langerhans cells, and merkel cells |
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Term
| What do keratinocytes do? |
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Definition
| produce keratin to make skin waterproof and protects skin |
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Term
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Definition
| produce melanin, melanin clusters over nucleus protecting the cell from UV radiation |
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Term
| What do langerhans cells do? |
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Definition
| they are macrophagic cells for the immune response and come from bone marrow |
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Term
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Definition
| they create the sensation of touch by making connections with the nerve cells |
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Term
| what are the 5 layers of the epidermis? from superficial to the deepest. |
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Definition
| stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale |
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Term
| What happens in the stratum basale? |
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Definition
| the deepest layer, has a single layer of mitotically active cuboidal or columnar cells, scattered among the stem cells are langerhans and merkel cells. the keratinocytes migrate to the surface then shed. also produce cells which migrate into dermis to produce sweat and oil glands |
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Term
| What happens in the stratum spinosum? |
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Definition
| melanocytes transferring melanin to keratinocytes |
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Term
| what happens in the stratum granulosum? |
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Definition
| nuclei and organelles begin to disintergrate, keratinocytes are flattened and contain keratohyalin |
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Term
| what does stratum lucidum contain? |
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Definition
| contain eleidin(keratin intermediate) |
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Term
| What does the stratum corneum contain? |
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Definition
| most superficial, contains flat, keratin filled, dead cells |
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Term
| How long does it take for the final shedding of cells from the stratum basale? |
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Definition
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Term
| What does the dermis contain? |
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Definition
| CT containing collagen and elastic fibers, highly innervated and vascularized. |
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Term
| what are the 2 layers of the dermis? |
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Definition
| papillary region, reticular region |
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Term
| What is in the papillary region? |
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Definition
| superficial, areolar CT, dermal papillae that increases surface area and responsible for ridges, meissner's corpsucles in some dermal papillae that are free nerve endings that are sensitive to touch |
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Term
| What is in the reticular region? |
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Definition
| deep layer, dense irregular CT gives skin strength, elasticity, and extensibility. attached to underlying organs via the subQ |
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Term
| What are the functions of the skin? |
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Definition
| regulation of body temperature, protection, sensation, excretion, immunity, blood reservoir, synthesis of vitamin D |
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Term
| What are the 4 kinds of glands in the epidermis? |
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Definition
| sebaceous, sudoriferous, mammary, ceruminous |
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Term
| What is a sebaceous gland? |
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Definition
| holocrine gland, secreting portions lie in dermis, secretes sebum (fats, proteins, salts), prevents hairs from drying and excessive evaporation of water from the skin |
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Term
| What is a sudoriferous gland? |
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Definition
| 2 types-apocrine and eccrine- both functionally merocrine glands, eccrine-most numerous(evaporative cooling function), apocrine- found only in axillary and pubic regions(not functional until puberty) |
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Term
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Definition
| modified sweat glands, milk production |
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Term
| What is a ceruminous gland? |
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Definition
| modified sweat glands in ear that secrete wax, can attach to sebaceous glands which combined secrete cerumen (barrier to foreign particles) |
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Term
| What is albinism and what does it affect? |
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Definition
| a disease in which a person has partial or complete loss of pigmentation of the skin, eyes, and hair. It affects the production of the enzyme tyrosinase which converts the amino acid tyrosinase into a melanin intermediate. |
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