chapter 5 Flashcards
(76 cards)
integumentary system
skin, sweat and oil glands, hair, nails
epidermis
epithelial cells and outermost superficial region (non-vascularized nutrients reach epidermis by diffusion from dermis)
dermis
middle region making up the bulk of the skin (vascularized)
hypodermis
(superficial fascia) deepest region w/ adipose and areolar connective tissue
(stores fat, anchors skin to underlying structures, absorbs shock and insulates)
where do males gain the most weight
abdomen
where do females gain the most weight
breast and thighs
what type of tissue is found in epidermis
keratinized stratified squamous epithelium
4 cell types in epidermis
keratinocytes, melanocytes, langerhan, merkel cells
keratinocytes
produce fibrous protein keratin (protection)
melanocytes
produce the brown pigment melanin
langerhans’
macrophages that help activate the immune system(ingest foreign substances and are key activators in immune system)
merkel cell
fn as touch receptors in association with sensory nerve endings
layers of epidermis
stratum basale, stratum spinosum, stratum grandulosum, stratum lucidum, stratum corneum
stratum basale
(basal layer) deepest epidermal layer firly attached to dermis. single row o stem cells undergoing rapid cell division
stratum spinosum
(prickly layer) several layers thik w/ cells that contain weblike system of intermediate filaments attached desmosomes (melanin grandules and langerhans are mostly in this layer)
stratum grandulosum
(thin) 3-5 layers, drastic changes in keratinocytes appearance occurs (keratinization starts) (keratohyaline and lamellated granules accumulate in the cells)
stratum lucidum
(clear layer) transparent band superfiscial to the stratum granulosum present in thick skin only (has few rows of flat dead keratinocytes
stratum corneum
(horny layer) outermost layer of keratinized cells that accounts for 3/4 of eridermal thickness
- waterproofing
- protection from abrasion and penetration
- rendering the body relatively insensitive to biological, chemical, and physical assaults
layers of dermis
papillary layer, reticular layer
papillary layer
thin layer areolar connective tissue w/ collagen and elastic fibers. superior surface contains peg-like projections called dermal papillae containing capillary loops, meisner’s corpuscles and free nerve endings. ( skin ridges w/ sweat pores create our fingerprints)
reticular layer
80% of thickness of skin made of coarse, irregularly arranged dense fibrous CT. (collagen fibers in layer add strength and resiliency to skin- run parallel to skin surface creating ridges) (elastin fibers provide stretch, recoil properties)
pigments contribute to skin color
melanin, carotene, hemoglobin
melanin
yellow-redish/brown- black pigment, responsible for dark skin colors
carotene
yellow to orange pigment, most obvious in palms and soles of feet