Please enable JavaScript.
Coggle requires JavaScript to display documents.
Anaiya Bernardo , period 1. Integumentary System - Coggle Diagram
Anaiya Bernardo , period 1. Integumentary System
Layers of the Skin
skin has 2 layers
- epidermis: thin, outer layer of stratisfied squamous epithelium
- Dermis: thicker, inner layer of CT, blood vessels, smooth muscle, and nervous tissue
- basement membrane separates epidermis from dermis and anchors these layers together
- Subcutaneous layer: layer underneath dermis, consisting of areolar and adipse tissues
- binds skin to underlying tissue, not apart of the skin
- adipose tissue insulates to conserve body heat
- contains major blood vessels that supply the skin
epidermis made up of stratified squamous epithelium
- lack of BV
- consist of 4 layers in most areas, 5 layers in thick skin
- Stratum basale is the deepest layer; it consists of dividing cells; it is well nourished by dermal blood vessel
-as basal cells divide, older cells called keratinocytes migrate towards skin surface
- As keratinocytes migrate outward, they harden, dehydrate, and die in a process called keratinization
**Epidermis(2)
- Stratum basale: innermost layer, dividing layer
-Stratum spinosum
- Stratum granulosum
-Stratum coreneum: outermost layer; dead, flattened, keratinized cells; these are continually being shed from the outer skin surface
-Stratum lucidum: layer between the stratum granulosum and the stratum corneum, which is found in the thick skin of the palms and soles
- the epidermis is important because, it protects against water loss, mechanical injury, chemicals, and microorganisms
Skin color
- All people have about the same number of melanocytes
- skin color is determined genetically and involves the amount of melanin that the melanocytes produce
- skin color results from a combination of genetic, inviormental, and physiological factors
- exposure to sunlight, UV light from sun lamps, and x-rays cause darkening of skin, due to an increase in melanin production
Skin Color(2)
- circulation within dermal blood vessels affects skin color
- wel-oxygenated blood has a pinkish color, due to hemoglobin
- poor oxygenated blood looks blue called cyanosis
- yellowish skin color can come from eating to many foods with carotene, or from jaundice due to liver disease
the dermis:
- binds the epidermis underlying tissue , border between epidermis and dermis is uneven, due to epidermal ridges and dermal papillae
- genetically determined pattern of friction ridges formed by dermal papillae provide for unique fingerprints
- dermis contains nerve fibers,sensory receptors, hair follicles, sebaceous glands and sweat glands
Accessory organs hair , nails, sweat glands
Nails: protective covering over the ends of fingers and toes
- consist of nail plate overlying layer of skin surface , called nail bed
Lununa: half-moon shaped structure at base of nail plate;most actively growing region of the nail root
- As new cells are produced, older ones are pushed outward and become Kertanitized
Glands: Sebaceous glands: Holocrine glands;entire cells filled with secretion are released
- Associated with hair follicles
- Secrete an oily substance called sebum, waterproof and moisturizes the hair shafts and skin
Sweat glands
- Merocrine glands; secretions exit cells via exocytosis
- 2types of sweat glands
- Eccrine: memrocrine glands that respond to body temp;more abundant type;,many found on forehead,neck,back
- Appocrine: memocrine glands which become active to puberty;respond to fear,emotional upset,pain,or sexual arousal
Modified Sweat Glands
- cermunious glands: secrete wax in the ear canal, to trap dust and pathogens
- mammary glands: secrete milk to nourish babys
Hair follicles Hair can be found in nearby regions of the skin except palms,soles,lips,nipples,and portions of external genitalia
- basically, each hair develops from epithelial stem cells at the base of tube-like depression which is called hair follice
- the deepest part of the hair root is called the hair bulb; it is located at the base of the hair follice
- old cells are dying and pushed outward and die forming the hair shaft
Hair color and Properties hair color IS determined by GENETICS
- melanin produced by melanocytes is responsible for most hair colors;type and amount of melanin are factors
- genetic lack of melanin caused albinism
-smooth muscle cells called an arrector pili muscle , attaches to each hair follicle; when it contracts , in response to cold temp or emotional upset, it causes goose bumps
skin cancer
- Cutaneous carcinomas are the most common types of cancer, affecting moslty lightskin people over forty years of age regularly exposed in sunlight
- the ABCDE rule provides a checklist for melanoma,for asymmetry ,for border , for color , for diameter, and for evolution or change
skin function
Skin function
- protective covering; prevents many substances and pathogenic microorganisms from entering the body
- protection of underlying tissue
- conducts part of the process for making vitamin D
- body temp regulation, via sweat glands and activation, and vacillation or vasoconstriction of dermal blood vessels
- healing of wounds
role of skin in body temp regulation
- proper temp regulation is vital to maintaining metabolic reaction rates
-the skin plays a major role in temp regulation, with the hypothalamus controlling the process
-heat may be lost to the surroundings from the skin through radiation
healing of wounds
- **inflammation, in which blood vessels dilate and become more permeable, causing tissues to become red and swollen, is the body's normal response to injury
- dilated blood vessels bring in fluids,oxygen,nutrients, and immune cells to aid healing
The healing of a deep wound
- involves the formation of blood clot from the released blood
- the blood clot and dried tissue fluids from a scab to cover the wound, then leads to a scar
Burns
- any burn injuring only the epidermis is a superficial partial-thickness ( 1st degree)
- takes a few days to weeks with no scarring
- physicians use the rule of nines sub-diving the skins surface into regions, each accounting for 9% of the total surface area, this estimate is important in planning to replace body fluids and electrolytes lost from injured tissues and for covering the burned area with skin or skin substitutes
6.1 introduction
organs
- body structures composed of two or more different tissues that perform specific functions
- skin is the largest organ in the body by weight
- the skin and its accessory organs make up the intergumentary system