Hole's Human Anatomy and Physiology - Chapter 6 | 76 Questions and Answers 2023 Solved Correctly

organ - two or more kinds of tissues grouped together and performing specialized functions Integumentary system function - - composed of several tissue types - maintains homeostasis - protective covering - retards water loss - regulates body temperature - houses sensory receptors - contains immune system cells - synthesizes chemicals - excretes small amounts of wastes Epidermis - - outer layer - stratified squamous epithelium dermis - - inner layer - contains collagenous and elastic fibers subcutaneous layer (hypodermis) - - beneath dermis - areolar and adipose C.T Epidermis - - stratified squamous epithelium - keratinized - rests on basement membrane - lacks blood vessels- melanocytes provide melanin Epidermis thickest - on palms and soles (0.8-1.4mm) Five layers of epidermis (top to bottom) - - stratum corneum - stratum lucidum - stratum granulosum - stratum spinosum - stratum basale Stratum corneum - dead keratinized cells Stratum lucidum - only in thick skin-palms, soles Stratum basale - mitotic layer keratinization - process that happens as cells move up from basement layer - drying out Melanocytes - - located in the stratum basale - produce the dark pigment melanin Melanin - - gives skin color - also absorbs UV light Genetic factors that affect skin color - - varying amounts of melanin - varying size of melanin granules - albino lack melaninEnvironmental factors that affect skin color - - sunlight - UV light from sunlamps - x-rays Physiological factors that affect skin color - - dilation of dermal blood vessels (blush) - constriction of dermal blood vessels (cold, shock, sick) - accumulation of carotene (pigment in plants) - jaundice Dermis two layers - Papillary layer Reticular layer Papillary layer - - areolar - thin - superficial - dermal papillae Reticular layer - - dense irregular C.T. - most of dermis Dermal papillae - - extend into spaces between epidermal ridges - form fingerprints - genes determine pattern Dermis - - on average 1-2 mm thick - binds epidermis to underlying tissues - dense irregular connective tissue - muscle cells- nerve cells processes - specialized sensory receptors - blood vessels - hair follicles - glands Accessory structure of the skin - - originate from the epidermis - nails - hair follicles - skin glands Nail - protective covering - nail plate - nail bed - lunula Hairs develop from - epidermal cells at the base of hair follicle follicle extend into - dermis three parts of hair follicles - - hair root - hair bulb - hair shaft hair bulb - mitotic region hair shaft - kerantinized, dead , epidermal cells