INTRODUCTION The skin and its derivatives ( sweat andoil glands, hairs, nails) serve a number offunctions, mostly protective. Together,these organs are called the integumentarysystem.
FUNCTIONS OF THE SKIN• It insulates and cushions the deeper body organs and protects the entire body from mechanical damage ( bumps and cuts), chemical damage ( such as from acids and bases), thermal damage ( heat and cold), ultraviolet rays ( in sunlight), and bacteria.
FUNCTIONS OF THE SKIN• Protect the body’s internal living tissues and organs• Protect the body from dehydration.
FUNCTIONS OF THE SKIN• Protect the body against abrupt changes in temperature, maintain homeostasis.• Protect the body against sunburns by secreting melanin.
FUNCTIONS OF THE SKIN• Store water, fat, glucose, and vitamin D• Help excrete waste materials through perspiration
FUNCTIONS HOW ACCOMPLISHED Physical barrier contains keratin, whichMECHANICAL DAMAGE toughen cells, and pressure receptors, which alert the nervous system to possible damage Has relatively impermeable keratinized; CHEMICAL DAMAGE contains pain receptors , which alert the nervous system to possible damage Has an unbroken surface and “acid mantle” ( skin secretions are acidic, and thusBACTERIAL DAMAGE inhibit bacteria). Phagocytes ingest foreign substances and phatogens, preventing them from penetrating into deeper body tissues.
EPIDERMIS• made up of stratified squamous epithelium that is capable of keratinizing or becoming hard and tough.• Its main function is protection, absorption of nutrients, and homeostasis.
EPIDERMIS• Composed of five zones or layers called strata. From the inside of these called stratum basale, spinosum, granulosm, lucidum, and corneum.• It does not contain blood vessels.
EPIDERMIS• Most cells of the epidermis are keratinocytes (keratin cells), which produces keratin, the fibrous protein that makes the epidermis a tough protective layer.
DERMIS• It is a strong, stretchy envelope that helps to hold the body together.• The dermis is the middle layer of skin, composed of dense irregular connective tissue such as collagen with elastin arranged in a diffusely bundled and woven pattern.
DERMIS• The dense ( fibrous) connective tissue making up the dermis consists of two major regions- the papillary and the reticular area.
PAPILLARY LAYER• The papillary layer is the upper dermal layer region. It is uneven and has fingerlike projections from it’s superior surface, called dermal papillae, which indent the epidermis above.
RETICULAR LAYER• It is the deepest skin layer. It contains blood vessels, sweat and oil glands, and deep pressure receptors called Pacinian.
HYPODERMIS• The hypodermis, or subcutaneous tissue, is the layer of tissue directly underneath the dermis. It is composed mainly of connective and adipose tissue. Its physiological functions include insulation, the storage of energy, and aiding in the anchoring of the skin. This is the thickest layer of the integumentary system.
APPENDAGES OF THE SKIN• The skin appendages include cutaneous glands, hairs and hair follicles, and nails.
CUTENEOUS GLANDS• are all exocrine glands release their secretions to the skin via ducts.• They fall into two groups; sebaceous glands and sweat glands.
Sebaceous (Oil) Glands• These are found all over the skin, except on the palms of the hand and the soles of the feet.
Hair Follicles• is a skin organ that produces hair.• Attached to the follicle is a sebaceous gland.
Nails• is a horn-like envelope covering the dorsal aspect of the terminal phalanges of fingers and toes in humans, most non-human primates, and a few other mammals
RASH• is a change of the skin which affects its color, appearance or texture• may be localized in one part of the body, or affect all the skin.
BLISTERS• is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing (friction), burning, freezing, chemical exposure or infection
ATHLETE’S FOOT• is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas.• It is caused by fungi in the genus Trichophyton and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses.
SUNBURN• is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet(UV) radiation, commonly from the suns rays• Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness.
ALBINISM• is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes due to absence or defect of an enzyme involved in the production of melanin.
SKIN NEOPLASM• are skin growths with differing causes and varying degrees of malignancy.• Skin cancer generally develops in the epidermis (the outermost layer of skin), so a tumor can usually be seen
RASH• make use of aloevera gel or olive oil on rashes and this can cure it fast.
BLISTERS• Avoid wearing shoes that are too tight or that rub your feet.• Wear gloves to protect your hands when you are doing heavy chores or yard work.
SUNBURN• The best way to prevent a sunburn is to avoid sun exposure.• Stay out of the midday sun (from 10 in the morning to 4 in the afternoon)
ATHLETE’S FOOT• Keeping your feet clean and dry.• Wear leather shoes or sandals that allow your feet to breathe.• When indoors, wear socks without shoes.
ALBINISM• There is no known way to prevent albinism.• Genetic counseling should be considered for individuals with a family history of albinism or hypopigmentation.
SKIN NEOPLASM• Studies have suggested that avoiding sunburns, especially in childhood and adolescence, may reduce the incidence of melanoma skin cancer.