Question | Answer |
What are the accessory structures of the skin? | hair, skin glands, and nails |
what type of cells is hair? | dead keratonyte cells, stratified squamous |
Where on the body are their no hair? | palms, lips, soles of feet |
What is the scientific name for hair? | pili |
In what parts are their excessive hair? | scalp, arm pits, eyebrows |
What causes thickness and distribution of hair among body? | hormones |
What is the visible portion if the hair which pertrudes out of the skin? | shaft |
What is deep to the shaft and penetrates into dermis? | root |
What are the layers of the hair? | medula, cortex, cuticle, epithelial root sheath |
What is composed of interior and exterior root sheath? | epithelial root sheath |
What covers the hair follicle? | derma root sheath |
What is the bulgy part of the hair follicle? | bulb |
what type of cells does the bulb consist of? | germanal cells |
What do the cells undergo? | cell division |
Where do the germanal cells reside? | matrix region |
What type of glands are attached to each follicle? | sabaceous glands |
What type of muscle is the arrector pili muscle? | smooth muscle |
How are goosebumps formed? | when the arrector pili muscle contracts |
How long is the hair growth stage? | 2-6 years |
What is the resting stage? | hair growth stops |
What is the partial or complete hair loss? | alopecia |
What causes alopecia? | hormones, age, skin disease, kemotherapy |
What makes up hair color? | amount and type of melanin |
What amount of melanin does white hair have? | no melanin |
What amount of melanin does grey hair have? | a lack of melanin |
What type of hair is fine and nonpigmented? | lanugo hair |
During what period do you have lanugo hair? | 9-12 weeks after fertilization |
What does lanugo hair cover? | fetus body |
When does it shed? | before birth |
What type of hair replaces lanugo hair? | vellus hair |
What is the thicker courser hair? | terminal hair |
What masculizing sex hormone causes it? | androgen |
Where is androgen secreted? | testes, ovaries, adrenal glands |
What type of hair are males composed of? | 95% terminal, 5% vellus |
What type of hair are females composed of? | 35% terminal, 65% vellus |
What is hersutsium? | excessive hair growth |
What causes male-patter baldness? | androgens that may inhibit hair growth |
What are the diffierent glands? | sabaceous, sudoriferous, ceruminous-cerumen |
What do sabaceous glands excrete? | sebum |
what is sebum? | oily substance that lubricate hair, prevents from dryness, and is rich in lipids |
Where are sabaceous glands located? | dermis |
What skin problem is the inflamation of sabaceous glands? | acne |
What are the two different types of sweat glands? | eccrine and apocrine |
what causes sweat from eccrine? | elevated body temp |
what causes sweat from apocrine? | emotional stress, sexual excitement |
What is ceruminous? | modified sweat gland |
what is cerumen? | waxy substance |
Where is cerumen excreted? | ear canal |
What are nails made up of? | hard, dead, keratonized, epidermal cells |
What jobs do nails have? | protection, grasp small objects, scratching, protction against trauma |
What is the lanula made of? | densly packed with cells |
What is the cuticle composed of? | narrow band of epidermal cells |
What secures the nail to the finger? | hyponychium |
What factors contribute to nail growth? | season, time, and weather |
How does body react to excessive heat? | dilation of dermal blood vessels and sweating |
How does body respond to excessive cooling? | constricting dermal blood vessels, inactivating sweat glands, and shivering |
What active cells produce heat? | heart and skeletal cells |
What controls the skins role in temperature | hypothalamus |
blood vessels dilate and become more permeable, causing tissues to become red and swollen | inflammation |
What are superficial cuts filled with? | reproducing epithelial cells |
How are deeper cuts filled? | closed off by clots, covered by scabs, and eventually filled in by fibroblasts, making connective tissue |
How are epidermal wonds healed? | Repaired by enlargement and migration of basal cells, contact inhibition (cellular response), and division of migrating and stationary basal cells |
What are the four phases of deep wound healing? | inflammatory phase, migratory phase, a proliferative phase , and maturation phase |