Ch. 6 integumentary system

Malignant melanoma

Arises from melanocytes Less than 5% of skin cancers Can be successfully removed if caught early, but usually fatal if metastasizes Greatest risk factor is familial history Highest incidence in men, redheads, people who had severe sunburn as a child

3 types of skin cancer

Basal cell carcinoma Squamous cell carcinoma Malignant melanoma

Apocrine glands

These glands are concentrated in the groin and anal region, Axillary region and Beard area (males only) They produce sweat that contains fatty acids. Inactive until puberty. Produce sweat that is milky and contains fatty acids produces Bromhidrosis: Disagreeable body odor produced by bacterial action on sweat from apocrine glands

jaundice

a yellowing of the skin due to an abnormally high level of bilirubin in the blood

Hair, nails, and cutaneous glands

accessory organs (appendages) of the skin

Hypodermis

adipose tissue layer below the skin/dermis Subcutaneous tissue that contains more areolar and adipose tissue than the dermis Common site of drug injection due to many blood vessels

Two kinds of sweat glands:

apocrine and eccrine (merocrine)

Cyanosis

blueness due to oxygen deficiency

dermis

deeper connective tissue layer under the epidermis The _____ consists of two layers Papillary layer, reticular layer Composed mainly of collagen Well supplied with blood vessels, sweat glands, sebaceous glands, and nerve endings Houses hair follicles and nail roots Muscles of facial expression attach to dermis

Catagen:

degeneration stage of hair cycle Mitosis in hair matrix ceases and sheath cells below bulge die Base of hair keratinizes into a hard club—club hair 2 to 3 weeks

lanugo

is fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development.

Stratum corneum

layer of epidermis where dead keratinocytes exfoliate from the skin surface. Up to 30 layers Fingernails and toenails are hard derivatives of the stratum

Stratum granulosum

layer of epidermis where keratin filaments are bound together to form waterproof bundles. Keratinocytes die. 3-5 layers of flat keratinocytes Cells contain dark-staining keratohyalin granules

sebaceous gland

oil-secreting gland (sebum) in the dermis that is associated with hair follicles releases product into hair follicles Holocrine secretion style

papillary layer

outer layer of the dermis, directly beneath the epidermis. Made of areolar tissue a thin zone of more loosely organized tissue containing many "wandering" white blood cells. Allows for mobility of leukocytes and other defense cells Thin zone of areolar tissue in and near the dermal papilla The loosely organized tissue allows the diffusion of nutrients and the movement of white blood cells between the dermis and the avascular epidermis.

Epidermis

outermost layer of skin. made of Keratinized stratified squamous epithelium majority of cells found in the epidermis are keratinocytes Avascular (lacks blood vessels) Contains sparse nerve endings for touch and pain

Pallor

paleness due to decreased blood flow to skin The skin color that is most likely to result from anemia

Hair bulb

The base where a hair follicle originates in the skin is known as the __________.

hairs to stand on end with no apparent function

The contraction of the arrector muscles in humans causes __________.

melanoma

The least common, but most deadly, type of skin cancer is __________.

fluid loss

The most immediate threat to the life of a patient with severe burns is __________.

Anagen

The period of active hair growth in the hair cycle 6 to 8 years in young adults

Melanin

Most significant factor in skin color Produced by melanocytes, accumulates in keratinocytes Two forms of the pigment: Eumelanin—brownish black and Pheomelanin—reddish yellow (sulfur-containing)

Sudoriferous glands

glands that secrete sweat to the outside of the body; also assist in body temperature regulation

melanin, hemoglobin, carotene

3 pigments that can influence skin color

Anagen, catagen, and telogen

A hair cycle consists of three developmental stages in which order?

Sebum

An oily substance that helps moisturize the skin and hair Keeps skin and hair from becoming dry, brittle, and cracked

keratinocytes

Calluses or corns are the result of accelerated multiplication by ___________.

Skin cancer

Caused by UV exposure Most often on the head, neck, and hands. Most common in fair-skinned people and the elderly One of the most common, easily treated cancers Highest survival rates if detected and treated early

Nails

Clear, hard derivatives of stratum corneum Composed of thin, dead cells packed with hard keratin

Follicle

Contains the hair root. Two principle layers: Epithelial root sheath and Connective tissue root sheath

Melanocytes

Dark and light skinned individuals have the same number of _______ but darker skin produces greater amounts of melanin, it breaks down more slowly, Melanin granules more spread out

Reticular layer

Deeper layer of the dermis that supplies the skin with oxygen and nutrients made of dense irregular connective tissue Bundles of densely packed collagen fibers help the skin withstand stretching in many different directions. Stretch marks (striae)

Hirsutism

Excessive hairiness is called __________.

Vellus

Fine, pale hair that replaces lanugo by time of birth All of hair of children except eyebrows, eyelashes, and scalp hair This hair constitutes about two-thirds of the hair in women and one-tenth of the hair in men.

Stem cells, Keratinocytes, Melanocytes, Tactile cells, Dendritic cells

Five epidermal cell types

Skin markings

Flexion creases, friction ridges and patches of pigmentation are all examples of which of what?

Keratinocytes

Great majority of epidermal cells Synthesize keratin Epidermal cell

Third-degree burn (full-thickness burn)

Involves all of dermis and often some deeper tissues Often requires skin grafts Needs fluid replacement, infection control, supplemental nutrition

second degree burn (partial thickness burn)

Involves part of dermis May appear red, tan, or white; blistered and painful Two weeks to several months to heal and may leave scars

Skin

It begins the process of vitamin D synthesis. It acts as an important barrier to water and UV radiation. Is considered a sense organ.

stratum basale; stratum spinosum

Keratinocytes produced by mitosis in _______ or deepest part of _______

Stratum spinosum

Layer of epidermis where mitosis ceases. Keratinocytes are pushed upward as new cells are added below them Several layers of keratinocytes joined by desmosomes and tight junctions

stratum basale

Layer of epidermis where stem cells divide and keratinocytes are produced. Also contains a few melanocytes and tactile cells The fastest rate of mitosis happens in the __________.

Stratum basale, Stratum spinosum, Stratum granulosum, Stratum lucidum, Stratum corneum

Layers of epidermis from deepest to most superficial

Dendritic cells

Macrophages originating in bone marrow that guard against pathogens Found in stratum spinosum and granulosum Epidermal cell

apocrine glands

Mammary glands are modified __________ glands that develop within the female breasts.

Basal Cell Carcinoma

Most common type of skin cancer Least dangerous because it seldom metastasizes Forms from cells in stratum basale Small, shiny bump with central depression and beaded edges

first degree burn

Only involves the epidermis Redness, slight edema, and pain Heals within days

Hemangiomas (birthmarks)

Patches of discolored skin caused by benign tumors of dermal capillaries

Mammary glands

Produce milk Develop only during pregnancy and lactation Modified apocrine sweat glands Rich secretion released through ducts opening at nipple

Subcutaneous fat

Refers to subcutaneous tissue that is comprised predominantly of adipose tissue Energy reservoir, Thermal insulation Thicker in women and thinner in infants, elderly

Hair matrix

Region of mitotically active cells immediately above papilla Hair's growth center

eccrine sweat glands

Secretions from __________ glands contribute to the acid mantle that inhibits bacterial growth on the skin. Most numerous skin glands tubular glands that provide Watery perspiration to cool the body

Hair receptors

Sensory nerve fibers entwining follicles Piloerector muscle (arrector pili) Smooth muscle attaching follicle to dermis. These contract to make hair stand on end (goose bumps)

fingertips

Skin covering the __________ has sweat glands but no hair follicles or sebaceous glands.

Melanocytes

Synthesize pigment melanin that shields DNA from ultraviolet radiation Occur only in stratum basale but have branched processes that spread among keratinocytes and distribute melanin Epidermal Cell

Stratum lucidum

Thin, pale layer found only in thick skin (palmar, plantar) Keratinocytes packed with clear protein eleidin No nuclei or organelles

Alopecia

Thinning of the hair or baldness

Squamous Cell Carcinoma

This cancer arises from keratinocytes of stratum spinosum Lesions usually on scalp, ears, lower lip, or back of the hand Raised, reddened, scaly appearance later forming a concave ulcer Chance of recovery good with early detection and removal Tends to metastasize to lymph nodes and may become lethal

Medulla, Cortex, Cuticle

Three layers of the hair in cross section

Tactile cells

Touch receptor cells associated with dermal nerve fibers In basal layer of epidermis Epidermal cell

Stem cells

Undifferentiated cells that give rise to keratinocytes In deepest layer of epidermis (stratum basale) Epidermal cell

Skin, Liver and Kidneys

Vitamin D synthesis first takes place in the ____ before being completed in the ______ and _______

Epidermal water barrier

Water retention is fostered by tight junctions between skin cells and the waterproofing that occurs in the stratum granulosum Helps prevent dehydration Does not prevent the absorption of water by the stratum corneum when we soak in a bath ("prune fingers")

Downy, Vellus, Terminal hair

What are the 3 types of hair from finest to strongest?

Epithelial root sheath and connective tissue root sheath

What are the two principal layers of the hair follicle?

stratified squamous epithelium

What type of tissue is found in the most superficial layer of skin?

dendritic cells

Which cell type is ONLY located in two layers of the epidermis, the stratum spinosum and the stratum granulosum?

Merocrine glands

Which cutaneous glands are concerned with cooling the body?

Melanin deposited in keratinocytes

Which feature of the skin protects the body from UV damage?

Dermal Papilla

Which structure nourishes the hair cells? An extension of the vascular system into the hair bulb Only source of nutrition for hair Creates a wavy boundary that resists stress and slippage of dermis

Medulla

Which term refers to the core of loosely arranged cells and air spaces that is prominent in thick hair?

palms of hands, soles of feet

_____ and ______ have sweat glands, but no hair follicles or sebaceous (oil) glands

Testosterone

______ causes terminal hair on top of scalp to be replaced by vellus hair

Cerumen

__________ is/are formed partly from the secretions of glands in the external ear canal.

ceruminous glands

glands secrete a substance that combines with sebum to keep the eardrum protected and prevent foreign particles from entering the canal. They waterproof the ear canal, and coat the guard hairs of the ear. Kills bacteria Coiled, simple tubular glands in external ear canal Modified apocrine glands

Erythema

redness due to increased blood flow to skin

Telogen

resting stage of hair cycle When papilla reaches the bulge 1 to 2 months

terminal hair

scalp hair is made of ____ hair only hair that is pigmented Eyebrows, eyelashes, and the hair of the scalp. Male facial hair and some of the hair on the trunk and limbs