Exam #2 Chapter 5 Flashcards
-study that deals with the structure, function, and disorders of the integumentary system
dermatology
-also known as cutaneous membrane, covers the external surface of the body and largest organ of the body
skin
- superficial, thinner portion, composed of keratinized stratified epithelial tissue
- avascular
epidermis
- the _____ has 4 types of cells:
- kerainocytes, melanocytes, intraepidermal macrophages and tactile epithelial cells
epidermis
-the skin consist of two layers the _____ and ____
epidermis and dermis
-90% of the cells, produce keratrin and lamellar granules
keratinocytes
- tough, fibrous protein that helps protect the skin and underlying tissue
- protects against physical damage, heat, microbes
keratin
- produce 8% of cells in epidermis, which develop from ectoderm of a developing embryo and produce the pigment melanin
- hemoglobin in RBC’s
- carotene-vitamin A precursor
melanocytes
- a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging UV light
- located in epidermis in melanocytes
melanin
- arise from red bone marrow and migrate to epidermis, function is for immune response
- also called Langerhans cells
intraepidermal macrophages
- located in the deepest layer of the epidermis, contain flattened process of neurons called tactile disc, detect touch sensation
tactile epithelial cells (merkel cells)
- part of stratum granulosum in epidermis, lipid rich secretion
- function is waterproofing the skin
lamellar graules
-mealnin, keratin, and hemoglobin produces ____
skin color
- deepest layer of epidermis
- single row of cuboidal or columnar cells
- stem cells: actively dividing
- location of melanocytes and tactile epithelial cells
stratum basale
- 8 to 10 layers of keratinocytes in epidermis
- have spines of keratin that insert into desmosomes that gives strength and flexibilty
- superficial to stratum basale
stratum spinosum
- 3 to 5 layers of cells undergoing apoptosis (cell death) in epidermis
- keratin not being produced but stands out as cell dies
- release of lamellar granules to SG, SL, and SC
stratum granulosum
- only present in layers of thick skin such as fingerprints, palms, soles of feet
- 4 to 6 layers of flattened dead cells and thickened plasma membrane, in vepidermis
- extra layer of protection
stratum lucidum
- average 25 to 30 layers of dead keratinocytes, in epidermis
- basically membrane encloses packages of keratin
- layered in complex, wavy folds of protection
stratum corneum
- the deeper, thicker dense irregular connective tissue portion of the skin
- vasular, skin bleeds if cuts
- resist stress and structural support
dermis
- deep to dermis but not part of skin
- consist of areolar and adipose tissue, serves as a storage for fat
subcutaneous layer
-nerve endings in sub layer and dermis, that is sensitive to pressure
lamellated corpuscles
- top 1/5 half of the dermis
- superficial portion of dermis, areolar tissue
- small projections into the epidermis, contain:
- capillary loops
- corpuscles of touch (meissner)
- free nerve endings
papillary layer
-increases the dermis surface area, small nipple shaped structures
dermal papillae
-all dermal papillae contains blood vessels called ____
capillary loops
- tactile receptors in dermis
- nerve endings that are sensitive to touch
carpuscles of touch (meissner)
- in dermis, dendrites that lack apparent structural specialization
- gives signals of warmth, coolness, pain, tickling, and itching
free nerve ending
- deeper portion of dermis
- collagen and elastic fibers arranged in netlike manner=extensibility
- also contains glands, follicles, and vessels
reticular layer
- downward projections of epidermis between dermal papillae
- bonds epidermis and dermis, and increases surface area for improved grip
- sweat pores and ridges form fingerprints and foot prints
epidermal ridges
-the ____ of the skin are also called epidermal derivatives because they arise from the embryonic epidermis
EX: hair, glands (sebaceous, eccrine, apocrine), and nails
accessory structures
-columns of dead, keratinized cells bound with proteins
hair
- superficial portion of hair
- projects above the surface of skin
hair shaft
-portion of the hair deep to the shaft that penetrates the dermis, sometimes subQ
hair root
-base of each hair follicle and its surrounded dermal root sheath is an onion shaped structure called ____
hair bulb
-the hair bulb also contains the ____, the blood supply of the hair
papilla
- derived from stratum basale=site of cell division
- located in hair bulb
- similar to the epithelial layer
hair matrix
- smooth muscles that cause hair to stand up when stressed
- goosbumps
arrector pili
-bundle of dendrites in hair, sensitive to touch
hair root plexus
- located in the dermis
- oil glands, secrete sebum
- keeps hair soft, prevents water evaporation from skin
- inhibits bacterial growth
- most connected to hair follicles
sebaceous glands
- mixture of triclycerides, cholesterol, proteins, and inorganic salts
- located in sebaceous glands
sebum
-sweat glands, secrete perspiration
has two types eccrine and apocrine
sudoriferous glands
- born with
- most common sweat gland
- regulates temp via evaporation, limited removal of waste
eccrine
- develop around puberty
- sweat is milky or yellowish because it contains lipids and proteins
- bacteria + stuff to digest =body odor
- secretes exocytosis
apocrine
- produce cerumin, ear wax
- waterproofing, foreign body barrier
- develop soon after birth
ceruminous
-visible portion of the nail
nail body
-extend past the distal end, the finger or toe
free edge
-portion of the nail that is not visible, buried in a fold of skin
nail root
-skin below the nail plate that extends from the lunula to the hyponychuim
nail bed
- the epithelium proximal to the nail root
- contains dividing cells, which produce new nail cells
nail matrix
- the cuticle of the nail
- stratum corneum of the epidermis
eponychium
- thickened region of stratum coreum
- secures nail to finger tip
hyponychium
-thick white part of the nail
lunula
-plates of tightly packed, hard, dead, keratinized epidermal cells that form a clear, solid covering over digits
nails
