Human Anatomy & Physiology- Chapter 5: The Integumentary System: Vocab

Hematomas

"Blood swelling", clotted blood masses

Peripheral connective tissue sheath

"Fibrous sheath", composed the wall of a hair follicle, derived from the dermis.

Boils and carbuncles

"Little glowing embers". Inflammation of hair follicles and sebaceous glands in which an infection has spread to the underlying hypodermis; common on the dorsal neck. Carbuncles are composite boils. A common cause is bacterial infection.

Lunule

"Little moon" the region that lies over the thick nail matrix appears as a white crescent.

Lamellar granules

"a small plate", contain a water-resistant glycoplipid that is spewed into the extracellular space.

Hyponychium

"below nail" the thickened region beneath the free edge of the nail where dirt and debris tend to accumulate

Papilla of a hair follicle

"hair papilla", is a nipple-like of dermal tissue that protrudes into the hair bulb.

Stratum lucidum

"light", visible only in thick skin, is a thin translucent band just above the stratum granulosum.

Medulla

"middle", its central core, consists of large cells and air spaces. The only part of the hair that contains soft keratin, is absent in fine hairs.

Stratum spinosum

"prickly", is several cell layers thick

Porphyria

"purple" An inherited condition in which certain enzymes needed to form the heme of hemoglobin of blood are lacking.

Scleroderma

"scler = hard" An autoimmune disorder characterized by stiff, hardened skin due to abnormal amounts of collagen in the dermis that severely limit joint movements and facial expressions.

Vitiligo

"viti = vine, winding" The most prevalent skin pigmentation disorder, characterized by a loss of melanocytes and uneven dispersal of melanin, so that unpigmented skin regions (light spots) are surrounded by normally pigmented areas.

Pore

(Por = channel). The secretory part lies coiled in the dermis, and the duct extends to open in a funnel-shape

Albinism

(alb = white) Inherited condition in which melanocytes do not synthesize melanin owing to a lack of tyrosinase. An albino's skin is pink, the hair pale or white, and the irises of the eyes unpigmented or poorly so.

Ceruminous glands

(cera = wax) are modified apocrine glands found in the lining of the external ear canal

Hirsutism

(hirsut = hairy) Excessive hairness

Impetigo

(impet = an attack) Pink, fluid-filled, raised lesions (common around the mouth and nose) that develop a yellow crust and eventually rupture. Caused by staphylococcus infection, it is contagious, and common in school-age children.

Vellus hair

(vell = wool, fleece) The body hair of children and adult females is pale, and fine

Reticular layer

Accounts for about 80% of the thickness of the dermis, is coarse, dense irregular connective tissue.

Hair matrix

Actively dividing area of the hair bulb that produces that hair

Jaundice, or Yellow cast

An abnormal yellow skin tone usually signifies a liver disorder, in which yellow bile pigments accumulate in the blood and are deposited in body tissues.

Papillary layer

Areolar connective tissue in which fine interlacing collagen and elastic fibers form a loosely woven mat that is heavily invested with small blood vessels.

Alopecia

Baldness.

Black-and-blue marks, or Bruises

Black-and-blue marks reveal where blood escaped from the circulation and clotted beneath the skin.

Melanoma

Cancer of melanocytes, is the most dangerous skin cancer because it is highly metastatic and resistant to chemotherapy.

Malignant melanoma

Cancer of the melanocytes; can begin wherever there is pigment

Occlusion

Closure or obstruction

Terminal hair

Coarse, long hair of the eyebrows and scalp, which can be darker.

Melanin

Dark pigment formed by cells called melanocytes; imparts color to skin and hair. E.g. freckles and moles

Epithelial root sheath

Derived mainly from an invagination of the epidermis

Flexure lines

Dermal folds that occur at or near joints, where the dermis is tightly secured to deeper structures. E.g. The deep creases on your palms.

Pallor, or Blanching

During fear, anger, and certain other types of emotional stress, some people become pale. Pale skin may also signify anemia or low blood pressure.

Root

Embedded in the skin

Sebaceous glands (oil glands)

Epidermal gland that produce an oily secretion called sebum

Sudoriferous gland

Epidermal gland that produces sweat

Keratin

Fibrous protein found in the epidermis, hair, and nails that makes those structures hard and water resistant; precursor is keratohyaline.

Hair or pili

Flexible strands produced by hair follicles and consist largely of dead, keratinized cells.

Pus

Fluid product of inflammation composed of white blood cells, the debris of dead cells, and a thin fluid

Cuticle

Formed from a single layer of cells overlapping one another. E.g., shingles on a roof

Merocrine Sweat Gland

Glands that produce secretions intermittently; secretions do not accumulate in the gland.

Skin appendages

Include hair and hair follicles, nails, sweat glands, and sebaceous (oil) glands.

Contact dermatitis

Itching, redness, and swelling, progressing to blister formation; caused by exposure of the skin to chemicals (e.g., poison ivy oleoresin) that provoke an allergic response in sensitive individuals.

Dermis

Layer of skin deep to the epidermis; composed mostly of dense irregular connective tissue

Decubitus ulcer

Localized breakdown and ulceration of skin due to interference with its blood supply. Usually occurs over a bony prominence, such as the hip or heel, that is subjected to continuous pressure; also called a bedsore.

Rule of nines

Method of computing the extent of burns by dividing the body into a number of areas, each accounting for 9% of the total body area.

Mammary glands

Milk-producing glands of the breast.

Sebum

Oily secretion of sebaceous glands.

Cortex

Outer surface layer of an organ. A bulky layer surrounding the medulla, consists of several layer of flattened cells.

Follicle

Ovarian structure consisting of a developing egg surrounded by one or more layers of follicle cells; colloid-containing structure of the thyroid gland; B cell--rich region in lymphoid tissue.

Hemoglobin

Oxygen-transporting protein of erythrocytes.

Cutaneous

Pertaining to the skin.

Pheomelanin

Pigment that colors red hair

Dendritic cells

Protective cells that engulf antigens, migrate to lymph nodes, and present the antigen to T cells, causing them to activate and mount an immune response; those in the skin are sometimes called Langerhans cells.

Cathelicidins

Protective peptides that wounded skin releases large quantities.

Cutaneous sensory receptors

Receptors located throughout the skin that respond to stimuli arising outside the body; part of the nervous system

Redness or Erythema

Reddened skin may indicate embarrassment (blushing), fever, hypertension, inflammation, or allergy.

Nail matrix

Responsible for nail growth

Sweat gland

See Sudoriferous gland.

Exteroceptor

Sensory receptor that responds to stimuli from the external world.

Cornified/ Horny cells

Shingle-like cell remnants of the stratum corneum. E.g., dandruff

Integumentary system

Skin and its derivatives; provides the external protective covering of the body.

Cold sores (fever blisters)

Small fluid-filled blisters that itch and smart; usually occur around the lips and in the mucosa of the mouth; caused by a herpes simplex infection. The virus localizes in a cutaneous nerve, where it remains dormant until activated by emotional upset, fever, or UV radiation.

Papilla

Small, nipple-like projection; e.g., dermal papillae are projections of dermal tissue into the epidermis

Hair follicle

Structure with outer and inner root sheaths extending from the epidermal surface into the dermis and from which new hair develops.

Hypodermis

Subcutaneous tissue just deep to the skin; consist of adipose plus some areolar connective tissue.

Epidermis

Superficial layer of the skin; composed of keratinized stratified squamous epithelium.

Eccrine sweat glands

Sweat glands abundant on the palms, soles of feet, and the forehead.

Dermatology

The branch of medicine that studies and treats disorders of the skin.

Hair bulb

The deep end of a follicle, located about 4 mm (1/6 in.) below the skin surface.

Stratum basale

The deepest epidermal layer, is attached to the underlying dermis along a wavy borderline that resembles corrugated cardboard.

Nail bed

The deepest layers of the epidermis extend beneath the nail

Hair bulge

The hair matrix originates here; located a fraction of a millimeter above the hair bulb.

Basal cell carcinoma

The least malignant and most common, accounts for nearly 80% of cases.

Apocrine sweat glands

The less numerous type of sweat gland; produces a secretion containing water, salts, proteins, and fatty acids.

Defensins

The natural antibiotics that skin cells secrete

Cutaneous plexus

The network of blood vessels that nourishes this layer, lies between the reticular layer, and the hypodermis.

Stratum corneum

The outermost epidermal layer, that is 20 to 30 cell layers thick that accounts for up to three-quarters of the epidermal thickness.

Nail folds

The proximal and lateral borders of the nail are overlapped by skin folds.

Squamous cell carcinoma

The second most common skin cancer, arises from the keratinocytes of the stratum spinosum.

Arrector pili

Tiny, smooth muscles attached to hair follicles; contraction causes that hair to stand upright.

Burn

Tissue damage inflicted by intense heat, electricity, radiation, or certain chemicals, all of which denature cell proteins and kill cells in the affected areas.

Nail plate or body

Visible attached portion

Carotene

Yellow to orange pigment that accumulates in the stratum corneum epidermal layer and in fatty tissue of the hypodermis

Stratum ganulosum

consists of one to five cell layers in which keratinocyte appearance changes drastically and the process of keratinization begins.

Keratohyaline granules

help to form keratin in the upper layers.

Eczema

A skin rash characterized by itching, blistering, oozing, and scaling of the skin. A common allergic reaction in children, but also occurs (typically in a more severe form) in adults. Frequent cause include allergic reactions to certain foods (fish, eggs, and others) or to inhaled dust or pollen. Treated by methods used for other allergic disorders.

Glassy membrane

A thickened basal lamina

Bronzing

A bronze, almost metallic appearance of the skin is a sign of Addison's disease, in which the adrenal cortex produces inadequate amounts of its steroid hormones; or a sign of pituitary gland tumors that inappropriately secrete melanocyte-stimulating hormone.

First-degree burn

A burn in which only the epidermis is damaged.

Second-degree burn

A burn in which the epidermis and the upper region of the dermis are damaged.

Third-degree burn

A burn that involves the entire thickness of the skin; also called a full-thickness burn. Usually requires skin grafting.

Psoriasis

A chronic autoimmune condition characterized by raised, reddened epidermal patches covered with silvery scales that itch or burn, crack, and sometimes bleed or become infected.

Rosacea

A chronic skin eruption produced by dilated small blood vessels of the face, particularly the nose and cheeks.

Nail

A clear protective covering on the dorsal surface of the distal part of a finger or toe.

Epidermolysis bullosa (EB)

A group of hereditary disorders characterized by inadequate or faulty synthesis of keratin, collagen, and/or basement membrane "cement" that results in lack of cohesion between layers of the sin and mucosa. A simple touch causes layers to separate ad blister.For this reason, EB victims are called "touch-me-nots." In severe cases fatal blistering occurs in major vital organs. Because the blisters rupture easily, victims suffer frequent infections. Treatments are aimed at relieving the symptoms and preventing infection.

Hair follicle receptor or Root hair plexus

A knot of sensory nerve endings that wrap around each hair bulb.

Dermcidin

A microbe-killing peptide

Plexus

A network of converging and diverging nerve fibers, blood vessels, or lymphatics.