AP1 Chapter 6 – Flashcards

stratum basale; stratum spinosum; stratum granulosum; stratum lucidum; stratum corneum

the deepest layer in the epidermis layer

several layers of polygonal keratinocytes form this spiny layer

granular layer consists of three to five layers of keratinocytes superficial to the stratum spinosum

is a thin translucent region of about two to three cell layers that is superficial tot he stratum granulosum

is the most superficial layer of the epidermis

is found on the palms of the hands, and the soles of the feet. All five epidermal strata occur in the thick skin. The epidermis of thick skin ranges between 0.4 mm and 0.6 mm thick. It houses sweat glands but has no hair follicles or sebaceous (oil) glands; and contains all five epidermal strata and covers the soles of the feet and the palms of the hands

covers most of the body. It lacks a stratum lucidum, so it has only four specific layers in the epidermis. Thin skin contains the following structures: hair follicles, sebaceous glands, and sweat glands. The epidermis of thin skin ranges from 0.075 mm to 0.150 mm thick; and covers most body surfaces; it contains only four epidermal strata and lacks a stratum lucidum.

Melanin gives a yellow-brown to tan to brown or black color to the skin. (a) Melanosomes in melanocytes transport the melanin pigment to the keratinocytes, where the pigment surrounds the nucleus. (b) Melanin is incorporated into the keratinocytes primarily of the stratum basale

the papillary layer and the reticular layer

is the superficial region of the dermis that is deep to the epidermis. It is composed of areolar connective tissue, and it derives its name from the projections of the dermis called dermal papillae. The dermal papillae interdigitate with deep projections of the epidermis called epidermal ridges, much like two sets of egg crate foam stacked on top of one another.

forms the deeper, major portion of the dermis that extends from the papillary layer to the underlying subcutaneous layer. The reticular layer consists primarily of dense irregular connective tissue through which large bundles of collagen fibers project in all directions.

Lines of cleavage (tension lines) in the skin identify the predominant orientation of collagen fiber bundles. These are clinically and surgically significant because any procedure resulting in a cut perpendicular to a cleavage line usually is pulled open as a result of the recoil resulting from cut elastic fibers

When the skin is stretched beyond its capacity, some collagen fibers are torn and result in stretch marks, called striae. Both the flexibility and thickness of the dermis are diminished by effects of exposure to ultraviolet light and aging, causing either sagging or wrinkled skin.

The subcutaneous layer also called the hypodermis, or superficial fascia. It is not considered a part of the integument. This layer consists of both areolar connective tissue and adipose connective tissue. In some locations of the body, adipose connective tissue predominates, thus the subcutaneous layer is called subcutaneous fat. The connective tissue fibers of the reticular layer of the dermis are extensively interwoven with those of the subcutaneous layer to stabilize the position of the skin and bind it to the underlying structures. The subcutaneous layer pads and protects the body, acts as an energy reservoir, and provides thermal insulation.

Nails are scalelike modifications of the stratum corneum layer of the epidermis that form on the dorsal edges of the fingers and toes. They protect the distal tips of the digits and prevent damage or extensive distortion during jumping, kicking, or catching. Fingernails also assist us in grasping objects

free edge; nail body; nail root; nail plate; nail bed

Hair is found almost everywhere on the body except the palms of the hands and palmar surface of the fingers, the sides and soles of the feet and toes, the lips, and portions of the external genitalia. and The hair follicle is an oblique tube that surrounds the hair root. It always extends into the dermis and sometimes into the subcutaneous layer.

protection; facial expression; heat retention; sensory reception; visual identification; chemical signal dispersal

The two different groups of sweat glands in the skin are merocrine (eccrine) sweat glands and apocrine sweat glands

Dehydration, as water can escape from the body

pressure, touch, and temperature

Become perpendicular to the skin, resulting in the hair "standing on end"

secretes sebum; usually opens up into a hair follicle; coats the scalp hair with oil; and blockage and infection can cause pimples

Secretes earwax; and waterproofs the ear canal

the blood vessels of the dermis constrict

temperature regulation

it stabilizes the position of the skin and binds it to underlying structures

blood vessels

Protection, thermoregulation, secretion

sweat glands and sebaceous glands

blood vessels that proliferate and form a benign tumor

cut blood vessels release blood into the wound; bleeding is stopped by the clotting proteins and platelets

Acts as an energy reservoir; Provides thermal insulation; Pads the body; Protects the body

these include hair follicles, exocrine glands, nerve cells, and muscle fibers.

its excessive vascular network promotes rapid absorption.

the stratum lucidum and stratum corneum.

about 4 weeks

when exposed to UV radiation.

regeneration and fibrosis formation

sex hormones during puberty in both sexes

granulation tissue

Barrier to water loss; Calcitriol production; Heat regulation

a blood clot temporarily patches the edges of the wound together and acts as a barrier to prevent the entry of pathogens into the body

melanin, coratene, and hemoglobin

melanocytes

melanosomes

in lactating females, and pregnant females

the stratum granulosum and stratum spinosum.

Protection = acts as a physical barrier to physical injury, trauma, bumps, and scrapes. Prevents water loss = epidermis is water resistant. Temperature regulation = influenced by vast capillary networks and sweat glands in the dermis Sensory reception = nerve endings that detect heat, cold, touch

Epidermal dendritic

Clotting proteins; Antibodies; White blood cells

connective tissue fibrosis occurs

fingers, palms, soles and toes

Adipose tissue; Collagen fibers; Blood vessels

Protection = scalp hair covers the scalp and shields it from sunburn and injury; Heat retention = blanket of thick hair on scalp Facial expression = hairs of eyebrows; Sensory reception: hair root plexuses Visual identification = color and density of hairs of scalp Chemical signal dispersal = pheromones on hairs

the number of strata in the epidermis and the relative thickness of the epidermis, rather than the thickness of the entire integument.

Merocrine sweat glands

0.075 millimeters to 0.150 millimeters thick

stratified, squamous, keratinized epithelium

Calcitriol production; Heat regulation; Barrier to water loss

Lines of cleavage (or tension lines)

Self renewing; Indicator of health; Barrier; Washable

the stratum basale, stratum spinosum, and stratum granulosum

regeneration of the epidermis occurs due to division of stratum basale cells at the edge of the wound; the process of fibrosis fills the gap with connective tissue.

Vasoconstriction

Epidermal derivatives

Keratinized cells

Large epithelial cells; Can be stimulated by light pressure; Also called merkel cells; Can be stimulated by light touch

vellus hair in the axillary and pubic regions of the body.

chemicals that simulate sensory nerve endings in the dermis

Apocrine sweat glands

the stratum corneum layer of the epidermis

keratin protein

Vibration; Heat; Cold; Pressure

Stratum corneum: most superficial layer of epidermis; Stratum lucidum: seen only in thick skin; Stratum granulosum: keratinization begins in this layer; Stratum spinosum: keratinocytes attached to neighbors by desmosomes; Stratum basale: contains keratinocytes, and tactile cells.

keratinization by which the keratinocytes fill up with the protein keratin.

the dermis and the epidermis

hair, nails, exocrine glands and subaceous glands

the external acoustic meatus

it has neither a nucleus nor organelles

macrophages within the wound begin to remove the clotted blood.

sebum

the nail body, the nail root, and the free edge

fibroblasts and composed primarily of collagen fibers.

stratum corneum, stratum granulosum, stratum spinosum, and stratum basale.

the dermal blood vessels vasodilate so more blood can travel close to the surface and excess can be lost

an outer connective tissue root sheath, which originates from the dermis, and an inner epithelial tissue root sheath, which originates from the epidermis.

melanin production

Apocrine = axillary, anal, areolar, and pubic regions Merocrine = distributed throughout body Sebaceous = associated with hair follicles over much of the skin Ceruminous = external acoustic meatus Mammary: breasts

a sebaceous gland's ducts plugged with sebum

Dome-shaped lesions filled with a mixture of white blood cells, dead skin cells, and bacteria.

can be prone to scarring

a fluid-filled nodule that can become severely inflamed and painful, and can lead to scarring

a pilus

we are not sweating is a process called transpiration.

prevent both water gain and loss

some stretch and contraction in the dermis during normal movement.

capillary and cavernous

both heredity and sun exposure

desmosomes and cytoskeletal elements remain intact

vellus

cerumen

the aging process in skin

the resulting daughter cell enters the stratum spinosum and it begins to lose its ability to divide

in the dermis and epidermis

transdermal adminstration

to the surface of the epidermis via sweat ducts

into hair follicles

in the dermis, to reduce blood flow which allows the body to conserve heat.