A P Exam 2 Lesson 7 Describe the components of the integumentary system o Largest system of the body 16 of body weight 1 5 to 2 m2 in area o Made up of 2 parts Cutaneous membrane skin Accessory structures What are the accessory structures What are their functions o Originate in the dermis o Extend through the epidermis to skin surface o Includes hair nails multicellular exocrine glands Explain how the integumentary system is linked to the cardiovascular and nervous system o Connected to cardiovascular system by blood vessels in the dermis o Connected to nervous system by sensory receptors that detect stimuli for pain touch and temperature Describe the main functions of the cutaneous membrane o 1 Protection of underlying tissues and organs o 2 Excretion of salts water and organic wastes glands o 3 Maintenance of body temperature insulation and evaporation o 4 Production of melanin keratin vitamin D3 and storage of lipids o 5 Detection of touch pressure pain and temperature Describe the major layers of skin o Thin skin covers most of the body has four layers of keratinocytes o Thick skin covers the palms of the hands and soles of the feet has five layers of keratinocytes How are fingerprints formed Why are they important o Determined by genetics and uterine environment during fetal development o Ridge patterns on skin increases surface area and friction ensuring a secure grip Explain the difference between insensible and sensible perspiration o Insensible perspiration corneum lose approx 500 mL or 1 pint of H20 per day water excreted by sweat glands o Sensible perspiration interstitial fluid lost by evaporation through the stratum Explain how carotene and melanin affect skin color o Carotene can cause a yellowing of the skin and the amount of melanin synthesized can cause a difference in skin pigmentation What are the differences between these two pigments o Carotene orange yellow pigment found in orange vegetables o Melanin Accumulates in epidermal cells and fatty tissues of the dermis Can be converted to vitamin A used for maintenance of epithelia and photoreceptor function yellow brown or black pigment Produced by melanocytes in stratum basale stored in transport vesicles melanosomes Transferred to keratinocytes Albino individuals do not have melanocytes What kind of effect does UV light have on skin o Causes DNA mutation and burns that lead to cancer and wrinkles Explain how different conditions can affect skin color o Skin color depends on melanin production not number of melanocytes o Oxygenated red blood contributes to skin color Blood vessels dilate from heat skin reddens Blood flow decreases skin pales o Cyanosis bluish skin tint caused by sever reduction in blood flow or oxygenation o Illness and skin color Jaundice caused by build up of bile produced by the liver yellow color Pituitary tumor caused by sxcess MSH production extremely bronze tan Addison s disease disease of pituitary gland releases more ACTH similar effect on skin color as MSH Vitiligo loss of color due to loss of melanocytes probably caused by autoimmune reaction by antibodies Explain how vitamin D3 is produced and the importance of this vitamin o Production epidermal cells produce cholecalciferol vitamin D3 in the presence o Liver and kidneys convert vitamin D3 into calcitrol hormone that aids absorption o Importance insufficient vitamin D3 can cause rickets bending of weakened of UV radiation of calcium and phosphorus bones under body weight Caused by insufficient sunlight exposure of dietary intake of vitamin D3 added to milk by dairy companies Describe the different components of the dermis o Located between epidermis and subcutaneous later o Anchors epidermal accessory structures hair follicles sweat glands o Two components 1 Outer papillary gland 2 Deep reticular layer What are the functions of the collagen and elastic fibers o Collagen very strong resist stretching but bend easily provide flexibility easily bent or twisted collagen fibers to prevent damage to tissue o Elastic permit stretching and then recoil to original length limit the flexibility of How are cleavage lines related to these fibers and why are they important o Cleavage lines are related to this fibers because the cleavage lines are formed from the collagen and elastic fibers in the dermis o Importance resist force in a specific direction establish important patterns A parallel cut remains shut heals well A cut across right angle pulls open and scars surgeons choose incisions parallel to the cleavage lines to reduce scarring Describe the different conditions that can affect the skin o Sagging and wrinkles caused by dehydration age hormonal changes UV o Stretch marks thickened tissue resulting from excessive stretching of skin exposure pregnancy weight gain o Decubitis ulcers bedsores caused by problems with dermal ciculation Explain the location and function of the hypodermis o Superficial fascia or subcutaneous layer o Located below the dermis o Function Stabilizes skin Separates integument from the deep fascia around other organs The site of subcutaneous injections using hypodermic needles o Is it part of the integumentary system No Describe the different types of hairs o Vellus hairs peach fuzz Soft fine Cover body surface o Terminal hairs Heavy pigmented Head eyebrows and eyelashes other parts of the body after puberty Vellus hairs replaced by terminal hairs on limbs armpits and public area Describe the different types of sweat glands o 1 Apocrine glands found in armpits around nipples and groin Secrete products into hair follicles begins at puberty Produce sticky cloudy secretions Break down of secretion by bacteria causes odors Surrounded by myoepithelial cells o 2 Merocrine eccrine glands widely distributed on body surface especially on palms and soles Coiled tubular glands Discharge directly onto skin surface Participates in sensible perspiration water salts and organic compounds relased Functions to excrete water and electrocytes cool skin flush microorganisms and harmful chemicals from skin Which modes of secretion does each use Which produces sweat for thermoregulation o Aprocrine sweat glands merocrine mode of secretion o Merocrine controlled independently sweating occurs locally Thermoregulation the main function of sensible perspiration works with cardiovascular system regulates body temp Describe the other glands found in the integumentary system o 1 Mammary glands produce milk o 2 Ceruminous glands produce cerumen
View Full Document
Unlocking...