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51 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are components of the integumentary system?
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Skin, glands, hair, and nails
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It does not mean "inside" anything
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What are the functions of the integumentary system?
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Mechanical protection (keranized epithelium); water barrier (protects C.T. from fluid evaporation); regulation of body temperature (blood supply); immune defense (lymphocytes in subepithelial C.T.); excretion of salts (sweat glands); sythesis of vitamin D; sensory awareness (large plexus of nerve fibers); sexual signaling; and indicator of health (skin complexion)
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There are nine.
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What are the layers of skin (starting with outermost)?
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Epidermis, dermis, and hypodermis
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Epi = outer/outside
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What are the five epidermal layers of thick skin (starting with innermost)?
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Stratum basale, stratum spinosum, stratum granulosum, stratum lucium, stratum corneum
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Layers are also called "strata"
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What are the two layers of the dermis?
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The papillary layer (top layer) and the reticular layer
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What is another name for the superficial fascia (or subcutaneous layer)?
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The hypodermis
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What is the hypodermis composed of?
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Loose C.T. and lots of blood vessels
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Hypodermic needles go right into the bloodstream
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Which type of skin (thick or thin) has hair follicles?
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Thin skin
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Thick skin is only on the soles of feet and palms of hands
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What are keratinocytes?
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The most numerous skin cell; produces keratin, an intermediate filament protein
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Look at the name
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What are melanocytes?
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Make up about 10% of epidermal cells; derived from neural crest cell (melanoblasts), so it has a dendritic shape. They produce melanin, injecting it into keratinocytes via cytocrine secretion.
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What are Merkel cells?
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Pressure receptors in the epidermis; contacts myelinated nerve fibers projecting from the dermis into the epidermis (associated with nerve plate)
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They're "nerve-"wracking
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What are Langerhan's cells?
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Come from bone marrow precursor; are dendritic-shaped antigen-presenting cells (part of the reticuloendothelial system); They DO NOT junction with keratinocytes-can move around
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Reticuloendothelial friends
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Where do Langerhan's cells go when they leave the epithelium?
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They pass into the C.T., then travel through lymphatic capillaries to lymph nodes via afferent lymphatic vessels
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Travel with lymph
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When are Langerhan's cells particularily used as antigen-presenting cells to interact with T-cells?
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During the initiation of cutaneous hypersensitivity reactions
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If it's wet, keep it dry, if it's dry, keep it wet
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What cells are found in the stratum basale?
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Keratinocytes, Merkel cells, and melanocytes
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Three main ones
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How do keratinocytes in the stratum basale join the basal lamina?
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Using hemidesmosomes
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Why is the stratum basale also called the stratum germaninativum?
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Because there is an abundance of stem cells and a lot of mitotic activity
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How many cell layers thick are the three cellular layers of the epidermis?
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Basale, one cell layer; spinosum and granulosum, several layers
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One is not like the others...
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What are the "spines" in the stratum spinosum?
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Keratinocytes are joined by bridges of cytoplasm (desmosomes), and shrinkage artifact causes cells to appear to have spines
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Shrinkage artifacts
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What cells are in the stratum spinosum?
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Keratinocytes and Langerhan's cells
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In what layer do keratinocytes die?
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The stratum granulosum
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What layer of the epidermis has a glycolipid coating (water barrier of epidermis)?
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The stratum lucium
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What are the layers of the epidermis of thin skin?
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The stratum basale, stratum spinosum, and stratum corneum
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What does the papillary layer of the dermis contain?
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Loose C.T., papillae (bumps where it meets the basal lamina of the epidermis), lymphocytes, macrophages, and nerves
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What do the papillae of the dermis contain?
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Capillary loops and special nerve endings
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What is the reticular layer of the dermis composed of?
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Dense irregular C.T.; collagen and elastic fibers
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Which layer of the dermis contains sweat and sebaceous glands (and hair follicles)?
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The reticular layer
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It's not the papillary layer
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What layer of the skin contains circulatory elements that help regulate body temperature?
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The dermis
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Blood vessels are in the C.T.
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How does the vascular plexus in the dermis carry blood (starting in the papilla)?
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Capillaries (within dermal papilla) to subpapillary plexus to the cutaneous plexus to the hypodermic/subcutaneous plexus (in hypodermis); there they nourish adipose tissue, sweat glands, and deeper segment of hair follicles
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Why are Langer's lines important?
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Cutting with these tension lines in skin reduces scarring
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What does the hypodermic layer contain?
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Loose C.T., subcutaneous fat, vascular and nervous elements, and portions of sweat glands and hair follicles
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What are the two types of sweat glands?
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Eccrine and apocrine glands
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E and A
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What type of secretion do eccrine and apocrine glands use?
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Merocrine secretion
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What is the structure of eccrine glands?
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Prominent secretory and ductal cells; coiled tubular shape
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What allows sweat glands to contract (allows "sweating")?
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Myoepithelial cells innervated by sympathetic nerves
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Where are myoepithelial cells located in sweat glands?
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Between the basal lamina and clear cells
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Which sweat glands are sensitive to aldosterone?
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Eccrine sweat glands (excretory portion partially reabsorbs NaCl and water under aldosterone influence)
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When do apocrine sweat glands become active?
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During puberty; the secretion is broken down by bacteria and results in BO
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Where is the secretory portion of apocrine sweat glands located?
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In the dermis and the hypodermis
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Where do apocrine sweat glands open up to (where do the secretions come to the surface)?
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In the hair follicle
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What are the differences between eccrine and apocrine sweat glands?
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Apocrine glands are bigger (secretory acini are larger)and less numerous
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What is the only (modified) apocrine gland that actually uses aprocrine secretion?
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Mammary glands; other modified apocrine glands are ceruminous (ear wax) and moll (eye crud)
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What is a pilosebaceous gland?
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A sebaceous gland associated with a hair follicle
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What type of secretion do sebaceous glands employ?
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Holocrine secretion
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How do sebaceous glands expel their secretory material?
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Use arrector pili muscle (smooth); NO myoepithelial cells
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What do sebaceous glands secrete?
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A waxy, sebaceous material; oily secretion released on surface of hair and epidermis
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Where is the secretory portion of sebaceous glands?
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In the dermis
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What are the two components of the hair follicle?
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The epithelial component (shaft, bulb) and the dermal papilla (has blood vessels feeding epithelial cells)
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What does the arrector pili muscle do?
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It's contractions cause goosebumps and squeezes sebaceous glands (empties them)
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What does aging do to the integumentary system?
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Loss of elasticity, loss of vascularity, reduction in sweat gland output, thinning of skin
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Why must the skin be slit halfway through the dermis during skin grafting?
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It leaves hair follicles and epithelial cells to produce a new dermis.
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