Advertisement Upgrade to remove ads

Skin Functions

Protect from invading bacteria. Holds in water and heat.


Outer layer of skin. Has five sub-layers.


Second layer of skin. Has two sub-layers.


Third layer of skin

Stratum Basale

Deepest layer of Epidermis. Single layer. Where mitosis takes places. Melanocytes, melanosomes, and Merkel cells.


Cells that make melanin.


Granules of melanin

Merkel cells

Docking station for nerve endings. Beacon for nerve signals.

Stratum Spinosum

Second deep layer of the Epidermis. Several layers. Keratinocytes, melanin granules, and Langerhan's cells.

Melanin Granules

UV shield for keratinocytes.

Langerhan's cells

Dendritic. Macrophages that activate the immune system.

Stratum Granulosum

Middle layer of Epidermis. 3-5 layers thick. Nuclei begins to disintegrate.

Stratum Lucidum

Clear band of cells. Found ONLY in thick Epidermis. Palms, soles of feet.

Stratum Corneum

Outer layer if Epidermis. 20 to 30 layers. No nuclei. Glycolipids from the cell matrix cause this layer to be waterproof.


Skin Pigment. Yellow, Redish-brown, black. Protects DNA from UV radiation. Chemical layer of skin.


Yellow/Orange pigment.


Red/Pink color. Caused by red blood cells in the dermis.


Accumulation of melanin

UV radiation

Destroys the body's folic acid stores.

Leathery skin

Caused by clumping of elastin fibers from excessive exposure to skin.


Redness. Blood vessel dilation due to: blushing, fever, hypertension.


Paleness. Blood vessels constrict due to: fear, stress, anemia.


Yellowing. Caused by a liver disorder.


Bruising. Due to blood escaping from the blood vessel and clotting beneath the skin.


Bluish tent to mucous membrane. Due to poorly oxygenated blood: respiratory problem

Papillary Layer

Superficial layer of Dermis. Areolar loose connective tissue. Abundant in blood vessels, pain receptors, and Meissner's Corpuscles.

Meissner's Corpuscles

Touch receptor in the papillary layer of the dermis. Tactile disc for light touch.

Dermal ridges

Caused by dermal papillae. Has sweat glands along crest. Leads to the fingerprint on the epidermis.

Reticular Layer

Deepest layer of dermis. Made up of Collagenous Fibers (elastic & reticular).

Tension lines

Less dense areas of collagen. Surgeons use to follow with incisions.

Flexure lines

Near joints. Attaching to deeper layers.


Stretch marks. Tearing of the dermis.

Eccrine Glands

Simple, coiled, and tubular. Most abundant. Palms, soles, forehead. Simple Cubodial Epithelium. Secrete sweat for overheating, or emotional response.

Apocrine Glands

Armpit and anogenital region. Secretes sweat with fatty acids into ducts.

Sebaceous Glands

Found all over body except hands and feet. Secretes only sebum. Impedes H2O loss, bactericidal, lubricates and softens hair.

Medulla of the Hair.

Central core. Large cells separated by air cells.

Cortex of the Hair

Surrounds the medulla

Cuticle of the Hair

Single layer. Keratinized. Outside layer of the hair.

Hair Bulb

A knot of sensory nerves surround this on the hair.


Dermal tissue that extends into bulbs. Contains capillaries for nutrients.


Natural thinning. In the 40s the hair is not replaced as fast.

Male Pattern Baldness

Genetic. Response to change in the body's testosterone levels.


Viral infection of the skin.


Hereditary. Rashes on skin. Often triggered by stress/hormonal changes.

Superficial Burn

First Degree burn. A sunburn.

Partial Thickness Burn

Second Degree burn. Blisters. 3 to 4 weeks to heal.

Full Thickness Burn

Third Degree burn. New skin can only regenerate from the edge. Usually requires surgery and grafting.

Basal Cell Carcinoma

Least fatal skin cancer. Starts in Basal layer of Epithelium. Slowly spreads to other layers until removed.

Squamous Cell Carcinoma

Skin cancer. Starts in the Spinosum layer. Can metastasize to the lymph nodes if not removed.

Malignant Melanoma

Most fatal skin cancer. Starts in the melanocytes. Can metastasize to the lymph and blood.

Low pH of Skin

Works with the acid mantel to retard bacterial growth. Chemical layer of skin.


Dermcidin. From sweat and sebum. Chemical layer of skin.


Secreted by epithelium. Directly kills bacteria. Chemical layer of skin.

Pacinian Corpusclese

Tough receptor in dermis. For deeper pressure.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording