Ap Chpt 5

subcutaneous

eratinocytes

Ceruminous glands are modified apocrine sweat glands found in the lining of the external ear canal. Their secretion mixes with sebum produced by nearby sebaceous glands to form a sticky, bitter substance called cerumen, or earwax, which is thought to deter insects and block entry of foreign material.

the secretions of apocrine sweat glands contain more fat and protein than do the secretions of eccrine sweat glands.

1. Keratinocytes The most abundant cells of the epidermis. 2. Keratin The protein found in the epidermis that is responsible for toughening the skin. 3. Merkel disc Cells plus a disc-like sensory nerve ending that functions as a sensory receptor for touch. 4. Dendritic cells Skin macrophages that help activate the immune system. 5. Cornified keratinocytes Cell remnants of the stratum corneum.

Dendritic cells activate the immune system

fibroblasts, macrophages, and mast cells

androgens stimulate vellus hair to become terminal hair Correct Androgens are group of chemically-related male sex hormones that induce male-specific body changes. Normally they are produced in females at very low levels. But when their levels rise, they can cause changes like hair growth on the body and face.

99% water, sodium chloride, trace amounts of wastes, and vitamin C

thermoregulation

apocrine gland: thermoregulation

melanoma

Melanomas are rare but must be removed quickly to prevent them from metastasizing.

Structures A, B, C, and D are located in the dermis

c

accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer

recticular layer

the stratum basale but not the dermal layers

metabolic

subcutaneous gland, made up dense connective tissue vascularized; nutrients diffuse through epidermis in dermis

epithelial cells

keratinocytes; in stratum basale, most popular cells melanocytes spider chaped cells synthesize melanin dendritic cells are activators of immune system, ingest foreign substances tactile cells function as sensory receptor

stratum basale- deepest cell layer, continuously renews cell population stratum spinosum- prickly cells, use desmosomes to hold cells tight statum granulosum- layers of flattened cells, contan granules that release lipids and form keratin stratum licidum- consists of dead keratinocytes stratum corneum- 30 layers, keratin, dead cells, glycolipids in extrcellular space

papillary- with aeolar connective tissue of elastic fibers allows cells to search and clean out bacteria - contain dermal papillae with touch receptors recticular- coarse dense irregular tissue. contain blood vessels, adipose tissues, collagen fibers. give skin strength and resiliency

produce more and darker melansomes and retain keratinocytes longer

tyrosine amino acids

straum corneum, orange color. can be converted to vitamin A which is good for vision and epidermal health

redness or blushing of skin,

during certain emotions, fear or anger, some peoples skin becomes pale

yellow skin, normally signifies liver disorder

metalic appearance of skin, signifies addisons disease

black and blue marks where blood escaped circulation..hematomas

dead keratinized cells or 3 layers; medulla, central area of large cells and air sacs, and soft keratin cortex, layer around medulla of flattened cells cuticle, single layer of cells overlapping each other, most heavily keratinized part. helps give hair stength

melanocytes at base of hair follicle and transferred to cortical cells

excesssive hairiness. may be from adrenal or ovarian gland that secrete abnormally large amounts of androgen

hair thining due to hair follicles falling out faster than they are replaced

rich bed of capillaries in underlying dermis

contain hard keratin

palms, soles of feet, forehead. secretory part lie in dermis. prevents body from overheating contains vitamin c, salts, water, microbe killing peptide dermicidin, and metabolic waste

axillary, and anogenital areas. release by exocytosis like eccrine glands have everything eccrine sweat does plus fatty substances and protein exact function not known but activated during pain and stress

found in external ear canal produces earwax, keeps bugs out and foreign substance

secrete milk

oil glands that are branched alveolar glands .secrete sebum on hair follicle, occasionally on pore. lubricates hair and skin and slows water loss when humidity is low

defensins

lipid soluble substances- oxygen, fat soluble vitamins.. k, a. and steroids oleorosins- like poinson ivy organic solvents- acetone, paint thinner salts of heavy metals - like mercury, lead

80% of skin cancers, statum basale cells proliferate, invading dermis and hypodermis

arise from keratinocytes of stratum spinosum can grow fast and metastisize if not removed

most dangerous, can occur anywhere where there is pigment and can metastasize quickly invade important organs like lymph nodes

only epidermis injured

epidermis and upper layer of dermis

enitre thickness of skin, nerve endings dead. not painful because nerves gone. severe fluid loss and infection. can lead to electrolyte imbalance, renal failure, fluid loss, circulatory shock

put on iv to replenish fluids and food calories. need thousands of calories to replace lost tissue and protein loss. skin graft quickly needed to avoid infection