Integumentary system

Hair shaft

Arrector pili: smooth muscle, hair stands up creating goose bumps. Sebaceous glands: lubricate hair, control bacteria growth.

Carotene

Orange yellow pigment in orange fruits and veggies. Source of vitamin A. Required in normal function of epithelial and photoreceptor synthesis.

Stratum granulosum

"Grainy layer" 3-5 layers of keratinocytes. Superficial cells are dead but deeper cells alive. Layer is named for the cells cytoplasmic granules which contain the protein keratin and an oily waterproofing substance. Make large amounts of keratin.

Stratum spinosum

"Spiny layer" consists of 8-10 layers of keratinocytes bound together by desmoso mess. First actively metabolizing cells are encountered here. Pigment melanin is foundin this layer which provides protection from UV light and also decreases production of vitamin D, so the body does not over produce it.

Sudoriferous glands

(Sweat glands) watery secretion/sweat. Exocrine. Apocrine and merocrine.

makes up what percent of your total body weight?

16%

Stratum corneum

1st epidermis layer. Exposed surface of both thin and thick skin. Normally 15-30 layers of keratinized cells. Composed of dead cells called keratinocytes. Have dry flakey appearance.

Papillary layer

1stlayer of dermis. Composed of loose connective tissue. Contains finger like projections called DERMAL PAPILLAE that project into the epidermis. Dermal papillae contain touch receptors (meissner's corpuscles) and capillary loops that provide blood supply to the avascular epidermis.

Aging and prolonged exposure to UV light.

Age: basal cell and melanocyte activity declines. Glandular activity declines. Less dendritic cells, less vitamin D3 produced, dermis thins, loss of elastic fibers causes sagging and wrinkle formation. Sun exposure and tanning: all the above are worse and occur faster.

Damage to epidermis

Blister formatiom

Keratinocyte

Bodies most abundant epithelium cells, dominatee the epidermis. Form several layers and contain large amounts of protein keratin. Making skin tough and resisting abrasion.

Basal cell carcinoma

Cancer of stratum basale, most common, due to excessive UV light exposure. Non metastic.

Meissner's corpuscle

Capillary loops that provide blood supply to the avascular epidermis.

Reticular layer

Composed of dense irregular collagenous.mit houses structures such as sweat glands, oil-producing sebaceous glands, blood vessels and pressure receptors called pacinian corpuscles.

Dermis

Composed of highly vascular connective tissue and contains two layers : papillary, and reticular.

Integumentary system

Composed of the skin and its accessory structures (hair, glands and nails) 2 layers: epidermis and dermis. Beneath the dermis sometimes called hypodermic (subcutaneous tissue) connects the skin to underlying surfaces and is not considered part of the integumentary.

Hair

Considered accessory structure to integumentary system. Consists of two basic parts hair shaft and hair root/bulb.

Epidermis

Contains layers of stratified squamous keratitis nixed epithelium. (Superficial to deep) stratum cornermen, stratum lucidum, stratum granulosum, stratum spinous, stratum basale.

Which layers of epidermis contain living cells?

Deepest 3 layers. Stratum basale, spinosum, granulosum.

Where do the cells of the epidermis obtain oxygen and nutrients from?

Diffusion from blood vessels in the dermis.

Second degree

Epidermal and dermal damage. Blisters.

First degree burns

Epidermal damage only. Redness, swelling, and pain.

The cutaneous membrane has two parts.

Epidermis and dermis

Stratum corneum

Exposed surface of both thick skin and thin skin.

Stratum basale

Form epidermal ridges (finger prints). Deepest layer and contains a single row of actively dividing cells. Often combined with the stratum spinosum and called the stratum germinativum. BASAL(stem) cells: divide, replace keratinocytes.

Third degree

Full thickness burn (damage to all of the skin). Gray-white, cherry red or black. No initial edema or pain ( nerve endings destroyed.

Accessory structure

Hair, hair follicles, sebaceous glands, sudoriferous glands, and nails. Located in dermis. Project through skin surface.

Epidermis and osmosis

Hypotonic solution (prune) and hypertonic solution.

Stratum lucidum

In the thick skin of the palms and soles of a glassy stratum "clear layer"

Melanocyte

Located in stratum basale. Manufacture both types of melanin and package it into intracellular vesicles called melasomes.

Hair shaft

Long, slender shaft composed of dead keratinized cells that project from the skins surface.

Hypodermis

Loose connective tissue also known as superficial fascia or subcutaneous layer.

Vitiligo

Lost of melanocytes, autoimmune.

Hair bulb/root

Made of dead keratinized cells. Embedded in the dermis. The structure surrounding the hair bulb is an epithelial tissue-lined sheath known as the hair follicle

Skin color

Melanin and carotene

Melignant melanoma

Melanocytes invade the lymphatic system. Highly metastic and resistant to chemotherapy.

Albinism

Melanocytes present, normal distribution, no melanin synthesis, genetic

Two types of receptors in the skin that detect fine touch are?

Merkel disks and meissner's corpuscles.

The dividing cells of the nail are located where?

Nail matrix

Nails

Nail root: produces the nail Eponychium: cuticle Lunula Nail body: covers the epidermal nail bed Free edge

Sebaceous glands

Oil glands - sebum. Holocrin: lubricate, protect, inhibit bacteria. Exocrine.

Keratinization

Or cornification action is the formation of protective, dead, superficial layers of cells filled with keratin. Occurs on all exposed skin surfaces. Cells move from stratum basale to stratum (deep to superficial) in 15-30 days.

Pacinian corpuscle

Pressure receptor in the dermis.

Nails

Primarily made of dead keratinized cells. Consists of a nail plate surrounded by folds of skin on all three sides known as nail folds. The nail plate is formed by a group of dividing cells proximal to the nail fold called the nail matrix.

Hair follicle

Produces non living hair

Dermal papillae

Projections in the dermis that indent the epidermis. Strengthen attachment b/n epidermis and dermis.

General functions of the integumentary system

Protection: of underlying tissues and organs, excretion of salts/water/organic wastes (glands)maintenance of normal body temp (insulation and evaporation), production of melanin, production of keratin, synthesis of vitamin D, storage of lipids, detection of touch! Pain, vibration, and temperature stimuli, and coordination of immune response.

Hair root

Root hair plexus.

Sebaceous glands

Secrete sebum (oil) into a hair follicle.

Sweat glands

Secrete sweat through small pores.

Stratum lucidum

Single layer of translucent "glassy" dead cells found only in the skin of the palms and soles of the feet. Cells = flattened, densely packed.

The epidermis is..

Stratified squamous epithelium. Also avascular, epidermis cells rely on diffusion of oxygen and nutrients from capillaries within the dermis.

Papillary layer

Superficial layer of the dermis; loose connective tissue.

Epidermis vs dermis

Superficial, epithelium. Deep, connective tissue.

The integumentary system has two major parts

The cutaneous membrane (skin) and the accessory structure.

Thick skin vs thin skin

Thick: palms of hand and soles of feet. 5 layers of keratinocytes. Thin: found everywhere else. 4-5 layers of keratinocytes.

Insensible perspiration and sensible perspiration

Unable to see or feel sense of water loss and evaporation of interstitial fluid through epidermis. Aware of sweat produced by active sweat glands.

Richets

Vitamin D3 deficiency, bones abnormally weak and flexible. Usually in kids with inadequate amount of vitamin d3 in diet.

Melanin

Yellow brown pigment produced by melanocytes in stratum basale. Stored in melanosomes and carried to keratinocytes. Protects cells from UV light damage (damages DNA) difference of skin color b/n individuals due to the rate of melanin synthesis not number of melanocytes.