Integumentary system Flashcards
What is the function of hair and nails?
Extensions of the body which protect it from environmental damage.
What is the function of exocrine glands?
secrete sweat, oil, wax that help regulate body temperature.
What are 5 main functions of the integumentary system?
- Protection to UV radiation (thermal agents)
- Natural barrier to microorganisms
- Prevention of dehydration by reducing evaporation
- water proofing
- Synthesis of V.D
What are the 2 layers of the skin?
- Epidermis
- Dermis
What tissue composes the epidermis?
Stratified squamous keratinized epithelium
What tissue type composes the dermis?
Thick layer of fibro-elastic connective tissue
What tissue type composes the subcutaneous tissue?
loose connective tissue with adipose tissue
What are the (4) layers of the epidermis in thin skin?
- Stratum corneum
- Stratum granulosum
- Stratum spionsum
- Stratum basale
- Dermis -
What are the (5) layers of the epidermis in thick skin?
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
- Dermis -
What is the stratum corneum?
Dead, keratinized stratified squamous cells.
What is the stratum granulosum?
living cells that are filling with precursor to keratin (keratohylin) and dying as the move up
- basophil granules
What is the stratum spinosum?
Prickle cells and desmosomes
What is the stratum basale?
location of mitosis
What is stratum lucidum?
clear layer between the corneum and granulosum layer of thick skin
What are the two layers of the dermis ?
- Papillary dermis
- Reticular dermis
What tissue type composes the papillary dermis?
loose areolar connective tissue with collagen and elastin fibers
What tissue type composes the reticular dermis?
Dense irregular connective tissue with elastin fibers and collagen.
What is the function of the papillary dermis?
Defences against infections (phagocytes)
Nerve fibers + touch receptors (Meissner corpuscle)
What is the function of the reticular dermis?
- Sensory
- movement of the body (elastisity of the skin)
- hydration of the skin (collagen bind to water)
What tissue composes the hypodermis?
loose areolar connective tissue with adipose tissue
What is the function of the hypodermis?
fat storage
insulation
cushioning
connects skin to underlining muscle + bone
How is lipids stored in this system?
Stored in the hypodermis, adipocytes store fats within adipose tissue.
What are the accessory structures?
- Skin
- Hair
- Sebaceous glands
- Sweat glands
- Nails
What is hair and what are the functions specific to hair?
- Keratinous filaments growing out epidermis
- protection, sensory input, thermoregulation, communication
What does sebaceous glands produce?
Sebum - oil coats hair + skin
What is the function of sebaceous glands?
lubrication
prevent loss of moisture
antibacterial properties
What are the two kinds of sweat glands?
- Eccrine sweat glands
- Apocrine sweat glands
Where are eccrine sweat glands located and what are their function?
- Palms, Soles, Forehead
- secrete hypotonic sweat for thermoregulation
Where are apocrine sweat glands located and what are their function?
- Hairy areas (armpits, genitals)
- produces a thicker sweat that is emptied into hair follicle
- subject to bacterial decomposition = smell
What are nails composed of and what are their function?
- Densely packed dead keratinocytes
- protects the tips of fingers and toes from damage.
How is Vitamine D synthesized by the body?
- Exposure to UV radiation
- Cholesterol in skin synthesizes cholecalciferol which is then converted into calcidiol by the liver and then converted to calcitriol (active chemical of Vit.D) by the kidney
What is eczema ?
Allergic reaction characterized by swelling, flaking, bleeding skin. Managed with moisturizers, corticosteroids and immunosuppressants
What is the leading cause of acne and its common location?
Bacteria causing infections, in rich sebaceous glands area such as the face and back.
Also caused by overproduction and accumulation of sebum and keratin = clogged hair follicle.
What is basal cell carcinoma?
Cancer of the stem cells in the stratum basale that undergo mitosis
loc: skin cells
What is squamous cell carcinoma?
Cancer of the keratinocytes of the stratum spinosum
loc: scalp, ears, hands
What is melanoma?
Cancer usually found in moles, uncontrolled growth of melanocytes. (worse)
