The integumentary system

Epidermis is ____, the dermis is ___ blood

avascular---vascular

Deep wound healing occurs in for phases

an inflammatory phase, migratory phase, a proliferative phase, a maturation phase

Found mainly in the skin of the axilla(armpit) join, areolae(pigmented areas around the nipples) of the breasts, and bearded regions. secretory portion of these glands located mostly in the hypodermis and their excretory ducts open into hair follicles. lipids+proteins+water, ions,glucose lactic acid. odorless till bacteria metabolize components.

apocrine sweat glands

The smooth muscle bundle, called the ___, extends from the superficial dermis of the skin to the dermal root sheath around the hair follicle. Physiological/emotional stress. It contracts. goose bumps. sensory nerve ending that is sensitive to touch.

arrector pili--hair root plexus

Connective tissue around muscles and bones

Fascia

These cells have long slender projections that extend between the keratinocytes and transfer melanin to them.

Melanocytes

Process by which cells form in the stratum basle, rise to the surface, become keratinized and slough off takes about

Four weeks

Strata of the epidermis

Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale

The base of each hair follicle is enlarged into an onion shaped, the ___. Houses nipple-shaped indentation, the ___ of the hair, which contains many blood vessels that nourish the growing hair follicle. Site of hair cell division.

bulb-papilla-hair matrix

most active form of vitamin d

calcitriol(hormone aids in calcium absorption from foods in gastrointestinale tract)

Blood vessels, nerve glands, and ahir follicles are embedded in the___ This layer can be divided into

dermis---thin superficial papillary region and a thick deeper reticular region

These are distributed throughout the skin of most regions of the body, especially skin of the forehead , palms, and soles. Secretary portion located in dermis, with its duct projecting upward to open as a pore at the surface of the epidermis. Consists of water , ions, glucose, lactic acid. Main function regulate body temperature through evaporation.(small role wastes,uric acid,ammonia)

eccine sweat glands

These glands start to function soon after birth but these other glands do not begin to function until puberty

eccrine---apocrine sweat glands

This type of healing occurs following injuries that affect only the epidermis THis type of healing follows wounds that penetrate the dermis

epidermal wound deep wound healing

What stimulates melanocytes to produce melanin? how is a tan lost?

exposure to UV, produce melanin, gives skin tanned appearance, protect body a against further UV radiation. melanin containing keractinoctyes are shed from stratum corneum

The process of car tissue formation is called

fibrosis

Deep wound: This phase, bleeding produces a blood clot in the wound, loosely unites wound edges. Helps eliminate microbes,foreign material , and dying tissue in preparation for repair. Increases permeability and diameter of local blood vessels, enhancing delivery of helpful cells.

inflammatory phase

These cells in the epidermis a;alert the immune system to the presence of potentially harmful microbial invaders. These cells in the dermis phagocytize bacteria and viruses that manage to by pass the other cells of the epidermis

langerhans cells, macrophages

This releases a product that inhibits evaporation of water from the skin surface, thus guarding against dehydration. Also blocks water in bath

lipids released by lamellar granules

The shaft and root both consists of there concentric layers of hair cells Inner __ is composed of cells that contain pigment in dark hair but mostly air spaces between cells in gray hair and absence of pigment in white hair The middle __ forms the major part of the shaft and consists of elongated cells. The __ of the hair, the outermost layer, consists of a single layer of thin, flat cells that are arranged like shingles on the roof of a house, with their free edges pointing toward the distal end of the hair

medulla, cortex, cuticle

Deep wound: Clot becomes a scab and epithelial cells migrate beneath the scab to bridge the wound. Deep to the epithelial cell bridge, fibroblasts migrate into the wound area and begin synthesizing collagen fibers and glycoproteins to become scar tissue, and damaged blood vessels begin to regrow. During this phase, the tissue filling the wound is called ___

migratory phase,, granulation tissue

***hair

...

These glands are secreted during sexual activities, but does not play a significant role in regulating body temperature

Apocrine sweat glands

Is a This is a yellow-orange pigment that gives egg yolks and carrots their color. these are stored in the stratum corneum and dermis after eating rich foods

Carotene

Modified sweat glands in external ear. Produce a waxy secretion Combined secretion of ceruminous and sebaceous glands is a yellowish material called __ or , or earwax

Cerminous glands. cerumen

Skin or cutaneous membrane

Covers the external surface of the body. Largest organ of the body. -16% body weight. 22 square feet, 4.5-5kg.

These contain capillary loops (blood capillaries) and can contain sensory receptors: _____ (meissner corpuscles) that are sensitive to touch and or free nerve endings, which initiate signals that produce sensations of warmth, coolness,pain, tickling and itching. Papillary region(dermis)

Dermal papillae (dermis)--corpuscles of touch

This is the second, deeper part of the skin, composed of dense irregular connective tissue containing a woven network of collagen/elastic fibers that provide tensile strength. *dermis thinner women, cellulite

Dermis

Ridges/grooves on tips of fingers. purpose?

Epidermal ridges increase surface area of epidermis, grip, increase fiction. unique to each individual.

These cells are most numerous epidermal cells, are arranged in four or five layers and produce keratin. Also produce lamellar granules, releases a waterproofing sealant that decreases water entry and loss

Epidermis

This layer is composed of keratinzed stratified squamous epithelium. Contains four principal types of cells

Epidermis Keratinocytes, melanocytes, langerhans cells and tactile cells

Skin consists of two principal parts

Epidermis (consists of epithelial tissue) Dermis (consists of connective tissue)

Hair follicle: This is a downward continuation of the epidermis. This is produced by the hair matrix and forms a tubular sheath of epithelium b between the external root sheath and the hair. the dermis surrounding the hair follicle forms the dermal root death

External root sheath internal root sheath

This is composed of columns of dead, keratinizied epidermal cells bonded together by extracellular proteins

Hair

This layer consists of areolar and adipose tissue. Fibers extend from the dermis to anchor the skin to this place, which in turn attaches to underlying fascia(connective tissue around muscles and bones)

Hypodermis (not part of skin) or subcutaneous layer.

This serves as a storage depot for fat and contains large blood vessels that supply the skin.

Hypodermis/subcutaneous layer

Functions of this system include thermoregulation, storage of blood, protection, cutaneous sensations, excretion, and absorption

Integumentary system

A tough fibrous protein that helps protect the skin and underlying tissues from abrasions, heat, microbes and chemicals.

Keratin

The hypodermis/subcutaneous layer also contains nerve endings called___ that are sensitive to pressure

Lamellated (pacinian) corpuscles

These cells participate in immune responses against microbes that invade the skin by helping other immune cells recognize an invading microbe and destroy it. These are easily damaged by UV light

Langerhan cells

Deep wound: This phase, scab sloughs off as the epidermis is restored to normal thickness. IN the dermis, collagen fibers become more organized, fibroblasts decrease in number, and blood vessels are restored to normal

Maturation phase.

Once inside keratinocytes, ___ forms a protective veil over the nucleus on the side facing the skin surface. In this way , it shields the nuclear DNA from UV light. * kertaincoytes gain some protection from leanin, melanocytes themselves are particular susceptible to damage by UV light.

Melanin

This is a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet (UV) light

Melanin

The amount of this pigment is located mostly in the epidermis, causes the skin's color to vary from pale yellow to reddish- brown to black. Difference of color is related to what? mole?

Melanin amount of melanin produced and transferred to keratinocytes. overgrowth of melanocytes

Three pigments that give a skin a wide vareity of colors

Melanin, carotene, hemoglobin

The visible portion fo the nail The part of the nail body that may extend past the distal end of the finger or toe. THe proximal portion of the nail that is buried in a fold of skin. The whitish crescent -shaped proximal end of the nail body A narrow band of epidermis, extends over the margin of the nail body

Nail body, free edge,nail root, lunula ,cuticle

This region makes up about 1/5 of the thickness of the total dermis. Contains thin collagen and fine elastic fibers. Surface area is greatly increased by dermal papillae, small nipple-shaped projections into the undersurface of the epidermis.

Papillary region

Deep wound: This phase is characterized by extensive growth of epithelial cells beneath the scab, deposition of collagen fibers by fibroblasts, and continued growth of blood vessels.

Proliferative phase

This region is attached to the hypodermis and contains bundles of thick collagen fibers/elastic fibers/ scattered fibroblasts and adipose cells. Blood vessels, nerves, hair follicles, sebaceous glands and sudoriferous(sweat) glands occupy the space between the fibers. This region provides the skin with strength, extensibility and elasticity due to what?

Reticular region(dermis) collagen and elastic fibers

Found in skin over all regions of the body except the palms and soles. secreting portion lies in dermis, opens into hair follicle Produce sebum, a mixture of triglycerides, cholesterol , proteins, and inorganic salts.

Sebaceous glands

The deepest layer of the epidermis. Composed of a single row of cuboidal or columnar keratinocytes. Some cells in this layer are stem cells that undergo cell division to continually produce new keratinocytes. Melanocytes and tactile cells are scattered among the keratinocytes of this layer

Stratum basale

This layer are closest to blood vessels in the dermis and therefore receive the most nutrients/oxygen.

Stratum basale cells

This layer consists of 25-30 layers of flattened dead keratinocytes. Cells continuously shed/replace by cells from the deeper strata. Cells are extremely thin/flat Multiple layers of dead cells help this layer protect deeper layers from injury and microbial invasion

Stratum corneum

This layer is located in the middle of the epidermis. Consists of 3-5 layers of flattened keratinocytes. As they move farther from their source of nutrition (dermal blood vessels), they can no longer carry on vital metabolic reactions, and die. This layer marks the transition between the deeper , metabolically active strata and the dead cells of the more superficial strata. distinct feature of this layer is the presence of membrane-encloused lamellar granules within the keratinocytes. Release lipid-rich secretion that is depoisted in spaces between teh cells of this layer + stratum lucidum and stratum corneum. A Lipid rich secretion acts as a water repllent sealant, retarding hte loss of water and entry of foreign materials

Stratum granulosum

This layer is present only in the thick skin of the fingertips, palms, and soles. It consists of 4-6 layers of flattened clear, dead keratinocytes that contain large amount amounts of keratin and thickened plasma membranes.

Stratum lucidum

Superficial to the stratum basal is this layer. Arranged in 8 to 10 layers of many-sided keratinocytes fitting closely together. Cells in the more superficial layers become somewhat flattened. Keratinocytes of this layer shrink and pull apart when prepared for microscopic examination, so that they appear to be covered with thorn spikes. Langerhans cells and projections of melanocytes are present in this layer

Stratum spinosum

These release sweat, perspiration into hair follicles or onto skin through ores. Divided into two main types

Sudoriferous glands/ sweat glands Eccine sweat glands, apocrine sweat glands

These cells are the least numerous of the epidermal cells. They are located in the deepest layer of the epidermis, where they contact a tactile (merkel) disc a flatted process of a sensory neuron. Function together to detect touch sensations

Tactile(merkel) cells

This surrounds the root of the hair, which is made up of an external root sheath and an internal root sheath.

hair follicle

Touch receptors (__) associated with hair follicles are activated whenever a hair is moved even slightly. Thus, hairs also function in sensing light touch

hair root plexuses

Oxygen carrying pigment in red blood cells

hemoglobin

THis tissue differs from normal skin in that its collagen fibers are densely arrange,d it also has less elasticity, fewer blood vessels, and may not contain the same number of hairs, skin glands, or sensory structures as undamaged skin. Lighter in color than normal skin, lack of blood vessels.

scar tissue

This coats the surface of hairs and helps keep them from drying and becoming brittle. Also prevents excessive evaporation of water from the skin, keeps the skin soft and pliable, and inhibits growth of bacteria

sebum

This is the superficial portion of the hair that projects from the surface of the skin. This is the portion of the hair deep to the shaft that penetrates into the dermis and sometimes into the hypodermis

shaft root

In response to epidermal injury, the cells surrounding the would break contact with basement membrane. and migrate across the wound until advancing cells from opposite sides of the wound meet this hormone stimulates these cells to divide and replace the ones that have moved into the wound.

stratum basale cells of epidermis. epidermal growth factor

The greatest contributor to epidermal thickness is the increased number of layers in the

stratum corneum