A&P integumentary system

parts of the integumentary system

epidermis, dermis, hypodermis, hair shaft, hair follicle, erector muscle, sebaceous gland, hair root, nails

how does skin provide biological protection?

protects the body from external factors such as bacteria, chemicals, and temperature.

how does skin provide mechanical protection?

skin cells form special anchoring points known as desmosomes, which increase the adhesion between cells.

how does skin provide chemical protection?

skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells.

how is vitamin D synthesized

ultraviolet radiation penetrates into the epidermis and photolyzes provitamin D3 to previtamin D3.

what is keratin

A type of protein found on epithelial cells, which line the inside and outside surfaces of the body. Keratin helps form the tissues of the hair, nails, and outer layer of the skin.

what is melanin

Brown, yellow-brown, or black pigment. Produced by melanocytes in stratum basale. Packaged into melanosomes (vesicles). Provides some protection against effects of UV radiation by shading cell nuclei.

what is keritinization

the process in which the outermost cells of the epidermis in vertebrates are replaced by cells containing keratin. This process occurs in the stratum corneum layer of the skin.

5 layers of thick skin epidermis (deep to superficial)

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

what is the germinal layer of the epidermis

basal layer (or stratum germinativum)

what is the papillary layer

named for dermal papillae in this region, composed of areolar tissue

what is the reticular layer

Composed of dense irregular connective tissue, contains both collagen and elastic fibers, contains blood vessels, lymphatic vessels, nerve fibers, and accessory organs (hair follicles, sweat glands)

what is dermatitis

a general term that describes inflammation of the skin, a common cause of dermatitis is contact with something that irritates your skin or triggers an allergic reaction.

what is bilirubin

a yellowish pigment that is made during the breakdown of red blood cells.

what is hemoglobin

Hemoglobin is red pigment found in red blood \n cells

what is carotene

Orange-yellow pigment

what are clinical signs given by skin color

blue/purple skin, pale skin, Jaundice (yellow skin), flushed skin.

what is basal cell carcinoma

Most common form of skin cancer, originates in stratum basale due to mutations caused by overexposure to UV radiation.

what is malignant melanoma

Most serious form of skin cancer, extremely dangerous, cancerous melanocytes grow rapidly and metastasize through \n lymphatic system, if detected early and removed surgically, the \n 5-year survival rate is 99 percent.

what is squamous cell carcinoma

a common form of skin cancer that develops in the squamous cells that make up the middle and outer layers of the skin. Squamous cell carcinoma of the skin is usually not life-threatening, though it can be aggressive.

what are the 3 stages of burns

first, second, and third degree

what are the signs and symptoms of a first degree burn

Only the surface of the epidermis affected. \n Example: most sunburns. \n Painful, skin redness (erythema) results.

what are the signs and symptoms of a second degree burn

Entire epidermis and maybe some of dermis damaged. \n Blistering, pain, and swelling occur. \n Infection can develop from ruptured blisters.

what are the signs and symptoms of a third degree burn

Full-thickness burns. \n Destroys epidermis, dermis, and damage extends into hypodermis. \n Sensory nerves are destroyed. \n Skin grafting usually necessary.

what are the main health concerns of a burn

Bacterial infection, which may lead to a bloodstream infection (sepsis) Fluid loss, including low blood volume (hypovolemia) Dangerously low body temperature (hypothermia).

what is the rule of nines of burns

Method of estimating percentage of surface area affected by burns, modified for children (different body proportions).

what are the parts of a hair

hair bulb, hair papilla, hair matrix, medulla, cortex, cuticle.

what is the hair bulb

expanded base of hair follicle

what is a hair papilla

peg of connective tissue filled with blood vessels and nerves

what is a hair matrix

actively dividing basal cells in contact with hair papilla

what is a medulla (part of hair)

layer of daughter cells formed at the center of the matrix

what is a cortex (part of hair)

intermediate layer deep to the cuticle

what is the cuticle

daughter cells produced at edges of the matrix; forms surface of the hair

what is the internal root sheath

Surrounds hair root and deeper portion of shaft, produced from hair matrix

what is the external root sheath

Extends from skin surface to hair matrix

what is the glassy membrane

Thickened, clear basement membrane

what is the connective tissue sheath

Surrounds the epithelial cells of the hair follicle

what is an apocrine sweat gland

secretes into hair follicles, surrounds the epithelial cells of the hair follicle, strongly influenced by hormones, include ceruminous glands and mammary glands.

what is a merocrine sweat gland

found on palms and soles, produce watery secretions with electrolytes, controlled primarily by nervous system, important in thermoregulation and excretion, some antibacterial action, secrete directly onto surface of the skin.

what are the three types of baldness

alopecia areata, telogen effluvium, anagen effluvium.

what is alopecia areata

sudden hair loss that starts with one or more circular bald patches that may overlap.

what is telogen effluvium

a reversible condition in which hair falls out after a stressful situation.

what is anagen effluvium

an abnormal loss of hair during the first stage (anagen) of the hairs growth cycle.