Ch.5 Integumentary system Flashcards
keratin
hollow cell protein. (makes skin waterproof)
functions of the skin (3):
Thermoregulation, protection, cutaneous sensations.
Thermoregulation
(via negative feedback) control body temp. cooling, dilation(opening up and allowing blood to flow), vasoconstriction(narrowing of blood vessels). Sweat gland secretion.
Protection
chemical, physical, biological.
Cutaneous sensations
exteroreceptors (respond to stimuli from outside body). sense, touch, pressure, vibration, temp, tickling.
excretion/ absorption
sweat secretion (water, salts, heat, waste). absorbs metals, fat soluble molecules.
synthesis of vit. D
required for uptake of calcium from digestive tract.
blood reservoir
skin blood vessels store up to 5% of bodys volume
immunity
epedermis contains langerhans cells–> self-presenting dendritic cells.
Skin(integument) 2 major regions:
epidermis, dermis.
epidermis
outermost superficial region.
dermis
vacular compartments are. (doesn’t have vascular tissue)
hypodermis
NOT PART OF SKIN. deepest (subcutaneous). Adipocytes(fat tissue)
7 functions of skin
thermoregulation, protection, cutaneous sensation, secretion/absorption, synth. of vit. D, blood resevior, immunity.
Epidermal cells 4 types:
keratincoytes, melanocytes, langerhans cell/ dendritic cells, merkel cells.
epidermal layers (5):
stratum basale, statum spinosum, stratum Granulosum, Startum Lucidum, Stratum Corneum.
dermis layers (2):
papillary, Reticular
papillary layer (D)
(areolar connective tissue) Collagen, elastin. Dermal papillae (grips), Messiners Corpuscles (touch)
Reticular layer (D)
(adipose tissue) hair follicles, dense irregular connective tissue
Skin colour (3) :
melanin, Carotene, Hemoglobin
Melanin:
located in epidermis, freckles and liver are accumulation of melanin. UV light increases melanin.
Carotene:
Yellowish-orange pigment. Found in stratum corneum, Vit.A. (yellowish tint= melanin + carotene)
Hemoglobin:
Caucasians have translucent epidermis due to little melanin. skin appears pink to red.
Sweat/ Sudoriferous Glands (4)
Eccrine/mecrocrine sweat glands, Apocrine sweat glands, Ceruminous glands, mammary glands
Sebaceous Glands:
simple alveolar glands found all over bod. Secrete oily sebum, waterproofs skin. (blackheads accumulation of sebum) ACNE AND PIMPLES.
Eccrine sweat glands:
hands, feet, forehead. (simple coiled tubular) Prevent overheating
Apocrine sweat glands
body odour, axillary/ anogenital areas.
ceruminous glands
apocrine glands in ear canal secrete cerumen(wax)
mammary glands
sweat glands secrete milk. (female reproduction)
Hair follicles (3)
root is below epidermis. contains harder keratin than in skin. (Inner medulla, middle cortex, outer cuticle) Outer= simple squamous keratinized. (PROTECTS, SENSORY, INSULATES)
7 hair follicle parts:
Root sheat, hair bulb =( papilla of the hair, matrix of bulb), Root hair plexus, arrector pili, sebacous glands.
Hair colour:
Melanocytes (enzyme) produce colour. (matrix produce melanin) Dark=true melanin / Blonde= less melanin. Grey hair = not producing melanin, air bubbles instead.
Nails
tightly packed keratinized cells. Nail body, Nail root.
Nail (3 parts):
Hyponychium (thick edge of nail), Epnychium (cuticle), Lunule ( white base of nail)
Skin Cancer (3):
Basal cell carcinoma (cancer cells of stratum basale (on face), Squamous cell carcinoma (keratinocytes (ears), malignant melanoma (melanocytes (most dangerous).
Burns:
1st deg. ( epidermal damage only) 2nd deg. (epi. and dermal damage, blisters) 3rd deg. (entire thickness of skin damage. Nerves destroyed) Skin grafting at 3rd.
