Anatomy & Physiology, Chapter 6

Stratum Granulosum

Third deepest layer of the epidermis, several layers of keratinocytes that fill with keratin, causing the cell to begin to die; also known as the granular layer

Keratinized stratified squamous epithelium

Tissue type of the epidermis

Freckles

Yellow or brown sports that represent localized areas of increased melanocyte activity, not an increase in melanocyte number

Nevus

A harmless localized overgrowth of melanin-forming cells; commonly called a mole

Cavernous hemangiomas

A hemangioma that involve larger dermal blood vessels and can last a lifetime; also called port-wine stains

Capillary hemangiomas

A hemangioma that is bright red or purple birthmark that is usually present at birth and disappears during childhood; also called strawberry-colored birthmarks

Melanin

A pigment produced and stored in melanocytes that occurs in a variety of black, brown, tan, and yellow-brown shades

Eleidin

A translucent protein found in the Stratum Lucidum (thick skin only) that helps protect the skin from UV radiation

Carotene

A yellow-orange pigment that is acquired from yellow-orange vegetables; is converted into vitamin A

Hemangioma

An anomaly that results in skin discoloration due to blood vessels that proliferate to form a benign tumor

Hemoglobin

An oxygen-binding protein present in red blood cells, gives the dermis a reddish tint in lighter-skinned individuals

Vasoconstriction

Blood vessels decrease in diameter

Vasodilation

Blood vessels increase in diameter

Tactile cells

Cells that are sensitive to touch; also known as Merkel cells

Melanocytes

Cells with long branching processes, that are scattered in the stratum basale; produce and store the pigment melanin

Keratinocytes

Most abundant cell type found all throughout the epidermal strata; produce keratin, a protein that strengthens the epidermis considerably

Stratum Corneum

Most superficial layer of the epidermis, 20-30 layers of deal, scaly, interlocking keratinized cells; also know as the hornlike layer

Epidermis

The epithelium of the integument

Arch, whorl, loops, combination

The four types of fingerprints

Keratinization

The process of keratinocytes filling with the protein keratin, which slowly kills the cell

Dermal Papillae

The ridges of the papillary layer

Dermatology

The scientific study and treatment of the integumentary system

Papillary layer

The superficial layer of the dermis found directly adjacent to the epidermis; formed of areolar connective tissue

Hemoglobin, melanin, carotene

The three things that contribute to skin color

Stratum Basale

Deepest layer of the epidermis, a single layer of cuboidal to low columnar cells attached to the basement membrane; also known as the stratum germinativum or basal layer

Thin skin

Found covering most of the body; between 0.075 and 0.15 mm thick

Thick skin

Found on the palms of hands and soles of feet; between 0.4 and 0.6 mm thick

Epidermal dendritic cells

Immune cells that help fight infection in the epidermis; also known as Langerhans cells

Melanosomes

Pigment granules

Stratum Spinosum

Second deepest layer of the epidermis, several layers of polygonal keratinocytes; also known as the spiny layer

Stratum Lucidum

Second to superficial layer of the epidermis, only present with thick skin; also known as the clear layer

Dermis

The connective tissue of the integument

Friction ridges

The contours of the skin surface on the fingers, palms, soles, and toes