CV physiology and histology

Skin histology

The study of the structure and composition of the skin tissue.

Skin Physiology

The study of the functions of the skin

Esthetician

A specialist in the cleansing, beautification, and preservation of the health of skin on the entire body, including the face and neck.

what are other terms for esthetician?

technicians, skin therapists, or specialists

the skin is the ? and one of the most important organ of the body.

largest

how many square feet the skin covers?

22 square feet

what is the weight of skin?

7 pounds

What does the skin protect against?

Outside elements and microorganisms

what does the skin protect in the body?

muscle, bones, nerves, etc

the skin is thinnest where?

eyelids

the skin is the thickest where?

palms of hands and soles of feet

healthy skin is

Slightly moist, soft, smooth, and somewhat acidic

the skin has how many cells?

million of cells

the skin has how many feet of blood vessels?

8 feet

the skin has how many feet of nerves?

32 feet

the skin has how many sweat glands?

650 sweat glands

the skin has how many oil glands?

100 oil glands

the skin has how many nerve ending?

1300 nerve endings

the skin has how many pressure receptors?

155 pressure receptors

the skin has how many cold and heat receptors?

12 cold and heat receptors

What are the 6 functions of the skin?

Protection, sensation, heat regulation, excretion, secretion, absorption

what is the acid mantel made up of?

sebum (oil), lipids, sweat, water

Epidermis

the outermost layer of skin and the only layer in direct contact with the outside environment.

What are the 2 layers of the skin?

epidermis and dermis

Keratinocytes

Composed of keratin, comprise 95 percent of the epidermis. They contain both proteins and lipids.

Keratin

A fiber protein that provides resilience and protection to the skin. found in all layers of the epidermis.

what are the epidermis layers?

stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

stratum corneum

The horny layer is the outermost layer of the epidermis.

acid mantle

Protective barrier of lipids and secretions on the surface of the skin

startum lucidum

The clear, transparent layer just never the skin surface; it consists of small cells through which light can pass.

stratum granulosum

The granular layer consists of cells that look like distinct granules. As they become keratinized, they move to the surface and replace the cells shed from the stratum corneum.

stratum spinosum

also known as the spiny layer, a layer of the epidermis that provides strength and flexibility to the skin, desmosomes are created here. Langerhans immune cells, melanosomes pigment distribution.

stratum germinativum

also known as the basal cell layer, the deepest layer of the epidermis that produces new epidermal skin cells and is responsible for growth. Merkle cells, keratinocytes, melanocytes, and lipids are produced here.

Mitosis

the division of cells

terminal differentiation

final stage of a cell in which it is highly specialized; can no longer divide and make more cells

lipid production

produces the necessary lipids that form cell membranes and hold the cells together.

Merkel cells

sensory cells/ touch receptors in the skin

Melanocytes

cells that produce melanin

Melanosomes

Pigment carrying granules that produce melanin, a complex protein.

Melanin

A pigment that gives the skin its color.

Melanin determines what?

skin, hair, eye color

Tyrosinase

The enzyme that stimulates melanocytes and thus produces melanin.

what are the 2 types of melanin?

pheomelanin and eumelanin

pheomelanin

Produces yellow to red pigments

Eumelanin

Produces brown to black pigments

fair skin contains about what melanosomes per keratinocytes?

20

Dark skin contains about what melanosomes per keratinocyte

200

Leukocytes

White blood cells that have enzymes to digest and kill bacteria and parasites. Responds to allergies.

T cells

attacks virus-infected cells, foreign cells, and cancer cells. A type of lymphocyte.

Dermis

Underlying or inner layer of the skin

the dermis can as be called what?

derma, corner, cutis, true skin

the dermis contains what?

blood vessels, lymph vessels, nerves, sweat and oil glands, hair follicles, arrector pili muscles, and papillae.

what are the 2 layers of the dermis?

papillary layer and reticular layer

Collagen

Fibrous protein that gives the skin form and strength. is 70% of the dermis. necessary of wound healing.

Elastin

The fibrous protein that forms elastic tissue and gives the skin its elasticity.

hyaluronic acid

Hydrating fluids found in the skin.

what are the two types of keratin?

Alpha (A-Keratin) and Beta (B-keratin)

alpha (a- keratin) is softer or harder?

softer

Beta (B-keratin) is softer or harder?

harder

What is the technical term for the nail?

Onyx

Glycolipids

Are ceramides, waxy lipid molecules important to the barrier function and water holding capacity. Fifty percent of lipids in the stratum corneum are ceramides.

free radicals

chemical particles with an odd number of electrons

Desquamation

cells repair by new cells coming to the surface from the lower stratums.

Why are antioxidants important?

they act as donors to neutralize free radicals

what can be the causes of free radicals?

UV exposure, unhealthy foods, chemicals, smoke, trauma from medical treatments.

Glycation

Caused by an elevation in blood sugar, glycation is the binding of a protein molecule to a glucose molecule resulting in the formation of damaged, nonfunctioning structures, known as Advanced Glycation End products( a.k.a. AGES). Glycation alters protein structures and decreases biological activity.

What is the 5 layers of the epidermis in order starting from the top layer going into the deepest layer

(stratum) corneum, lucidum, granulosum, spinosum, germinativum

Transepidermal Water Loss (TEWL)

Water loss caused by evaporation on the skin's surface.

Barrier function

Skins mechanism that protects us from irritation and intercellular transepidermal water loss (TEWL).

Fibroblasts

Cells that stimulate cells, collagen, and amino acids that form proteins to aid in healing.

Epidermal Growth Factor (EGF)

Stimulates cells to reproduce and heal.

arrector pili muscle

An involuntary muscle fiber attached to the underside & base of the hair follicle. contracts and causes 'goosebumps".

Heat regulation

Maintaining a body temperature of 98.6 Fahrenheit through the blood and excretion of perspiration. the body maintains thermoregulation through evaporation, perspiration, radiation and insulation.

sudoriferous glands

glands that secrete sweat to the outside of the body; also assist in body temperature regulation. Apart of the skins excretion function.

sebum (oil)

oily substance secreted by sebaceous glands

Sabaceous glands

appendages attached to follicles producing sebum (oil).

subcutaneous layer

connective and adipose (fat) tissue layer just under the dermis

reticular layer

The denser and deeper layer of the dermis is comprised mainly of collagen and elastin.

papillary layer

connects dermis to epidermis.

dermal papillae

membranes of ridges and grooves that attach to the epidermis.

Hair Papillae

\[dermis\]->{papillary layer}

Small, cone-shaped structures at the bottom of hair follicles; the papillae are filled with tissue that contains the blood vessels and cells necessary for hair growth and follicle nourishment.

Glycosaminoglycans (GAGs)

a large portion molecules and water binding substances found between the fibers of the dermis.

GAGs are

polysaccharides

Polysaccharides

a carbohydrate whose molecules consist of a number of sugar molecules bonded together.

Desmosomes

kertain filaments-the protein bonds that create the junctions between the cells.

Langerhans cells

part of the immune system. protects the body from infections by identifying foreign material (antigen)

lamellar immune cells

cells that contain lipids to maintain the barrier functions

Desquamation is also called

cell turn over

the sebaceous glands is responsible for

secreting oil

the sudorinferous gland is responsible for

excreting sweat

Ceramides

Waxy lipid molecules important to barrier function and water-holding capacity

UVA radiation (aging rays)

longer wavelengths ranging between 320-400 nanometer that penatrate deeper into the skin; cause genetic damage and cell death. contributes up to 95% of suns uv radiation

UVB radiation (burning rays)

wavelengths range between 290 to 320 nanometers. the rays have shorter, burning wavelengths that are stronger and more damaging than UVA rays. causes burning of the skin as well as tanning, skin aging, and cancer.

UVC radiation

the most powerful and dangerous form of UV radiation. reacts to the ozone layer and is from human made sources.

High-Energy Visible Light (HEV)

Know more as "blue light". light emitting from electronic devices, reported to penetrate the skin more deeply than UV rays; damages collagen, hyaluronic acid, and elastin

Microcirculation

circulation of blood from heart to Arterioles (small arteries) to Capillaries to Venules (small Veins) and then back to the heart.

Telangiectasia (couperose skin)

Capillaries that have been damaged and are now larger; Dilation of the capillary walls.

Rosacea

Chronic vascular disorder characterized by varying degrees of skin redness and congestion of the skin.

what are the basic material and building blocks of our body tissue?

proteins

What are the building blocks of proteins?

amino acids