Chapter 5 Flashcards
What is the largest organ system in the body?
Integumentary system
List the layers of epidermis starting deep to most superficial.
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (thick skin), stratum corneum
What is the difference between thick and thin skin?
Thick skin possesses 5 layers - stratum lucidum while thin skin only has 4 layers
What does melanin do and what cell produces melanin?
Melanin serves as a protection against UV radiation and gives skin and hair its pigmentation. The melanocytes produces melanin.
Why do the cells in the stratum granulosum look grainy?
Has keratin and keratohyalin that accumulates into lamellar granules.
What is the name of the protein that is found in the stratum lucidum?
Eleidin
How often is our stratum corneum getting replaced?
Every 4 weeks
What are the two layers of the dermis?
papillary and reticular layers
What are the two forms of melanin and what color do they produce?
Eumelanin - black and brown
Theomelanin - red
How long does it take for melanin synthesis to peak after UV exposure?
10 days post-exposure
Define hair follicle, hair shaft, and hair root.
Hair follicle - epidermal penetration of the dermis
Hair shaft - hair not anchored to follicle (usually at skin’s surface)
Hair root - anchored in hair follicle below the surface of the skin
What part of the nail is rapidly dividing?
Nail root
Name and define the three phases of hair growth.
Anagen phase - cell divides rapidly at hair root and push hair up and out
Catagen phase - transition from hair follicle’s active growth
Telagen phase - hair is at rest with no new growth
What are the two types of sweat glands and where do they empty their secretions?
Eccrine - duct has pore at skin’s surface that dumps sweat on skin
Apocrine - ducts empty in hair follicles
List the main functions of the integumentary system.
Protection, prevent dehydration, sensory organ, regulate body temperature and electrolyte balance, and synthesize vitamin D
