Chapter 4 study guide

What do the arrector pili muscles do?

Contract to cause hairs to stand up "goosebumps" and this helps to warm the body up

Hair shaft-

the part of the hair that projects from the surface of the scalp or skin; this part of the hair is dead keratinized cells

Reticular Layer-

(deepest skin layer) - Blood vessels, Sweat and oil glands, and deep pressure receptors (lamellar corpuscles) are located in this layer; nourishes the epidermis by diffusion from capillaries originating from this layer

Third degree-

(full-thickness burn) - Destroys epidermis and dermis; burned area is painless - Requires skin grafts, as regeneration is not possible - Burned area is blanched (gray-white) or black

fourth degree-

(full-thickness burn) - Extends into deeper tissues (bone, muscle, tendons) - Appears dry and leathery - Requires surgery and grafting - May require amputation

second degree-

(partial-thickness burn) - Epidermis and superficial part of dermis are damaged - Skin is red, painful, and blistered - Regrowth of the epithelium can occur

First degree-

(superficial burn) - Only epidermis is damaged - Skin is red and swollen

Stratum Lucidum-

(thick, hairless skin only) - is a thin translucent band of flattened dead keratinocytes. This layer is present only in thick skin, such as the palms of the hands and soles of the feet.

Stratum Corneum-

- Outermost superficial layer of epidermis; 20-30 cell layers of shingle-like dead cells are filled with keratin (protective protein prevents water loss from skin)

What 3 pigments control skin color and describe what each contributes to color

1.Melanin - Yellow, reddish brown, or black pigments; gives color to hair and skin darkening effect (tanning) 2.Carotene - Orange-yellow pigment from some vegetables 3.Hemoglobin - Red coloring from blood cells in dermal capillaries; Oxygen content determines the extent of red coloring

Hair follicle-

= is a structure of the skin that encloses the hair where the hair root is found

serous membranes-

= line open body cavities that are closed to the exterior of the body; occur in pairs, separated by serous fluid, with a visceral and parietal layer; produces serous fluid that reduces friction.

mucous membranes-

= moist membranes; line all body cavities that open to the exterior body surface; adapted for absorption or secretion

Cutaneous membrane-

= skin; only dry membrane; covers the body exterior; outermost protective boundary; protects from external environment and water loss

Arrector pili muscle-

= tiny muscles that attach to the base of a hair follicle at one end and to dermal tissue on the other end. In order to generate heat when the body is cold, the arrector pili muscles contract all at once, causing the hair to "stand up straight" ("goosebumps") on the skin.

What is the ABCDE's of skin cancer? What layer can the uncontrolled growth (cancer) occur? Hint: where does cell division occur in the epidermis?

? Stratum Basale (most) ABCDE's of Skin Cancer: A = Asymmetry - Two sides of pigmented mole do not match B = Border irregularity - Borders of mole are not smooth C = Color - Different colors in pigmented area D = Diameter - Spot is larger than 6 mm in diameter E = Evolution - One or more of the ABCD characteristics is evolving

What is acne, contact dermatitis, herpes simplex, malignant melanoma, impetigo, basal cell carcinoma, and squamous cell carcinoma?

Acne- infection of the sebaceous glands and the formation of pimples Contact Dermatitis - skin inflammation Herpes Simplex - virus that causes cold sores Malignant melanoma - cancer of the melanocytes Impetigo - staphylococcus bacterial infection causing water-filled lesions commonly around the mouth and nose Basal cell carcinoma - malignancy of the lowest epidermal layer - where rapid cell division is occurring Squamous cell carcinoma - cancer of the stratum spinosum cells

What is the rule of nines?

Criteria for deeming burns critical (if any one is met): Over 30 percent of body has second-degree burns Over 10 percent of the body has third- or fourth-degree burns Third- or fourth-degree burns of the face, hands, or feet, or genitals Circumferential (around the body or limb) burns have occurred Extent of a burn and the volume of fluid lost is estimated using the rule of nines Body is divided into 11 areas for quick estimation Each area represents about 9 percent of total body surface area The area surrounding the genitals (the perineum) represents 1 percent of body surface area Totals: Anterior and Posterior head and neck = 9% Anterior and posterior upper limbs = 18% Anterior and Posterior trunk = 36% Perineum = 1% Anterior and Posterior lower limbs = 36%

. What are the 4 types of membranes in the body, location of each, and function of each?

Cutaneous membrane = skin; only dry membrane; covers the body exterior; outermost protective boundary; protects from external environment and water loss. Mucous membranes (mucosae) = moist membranes; line all body cavities that open to the exterior body surface; adapted for absorption or secretion Serous membranes (serosae) = line open body cavities that are closed to the exterior of the body; occur in pairs, separated by serous fluid, with a visceral and parietal layer; produces serous fluid that reduces friction. Synovial membranes = loose areolar connective tissue only (no epithelial tissue); line fibrous capsules surrounding joints; line bursae; line tendon sheaths; secrete a lubricating fluid to cushion organs moving against each other during muscle activity

Stratum basale-

Deepest layer of epidermis; Lies next to dermis; Wavy borderline with thedermis anchors the two together; Cells undergoing mitosis; Daughter cells are pushed upward to become the more superficial layers; About a quarter of the cells in this stratum are the spidery, brown-to-black pigment-producing cells called melanocytes

What are the 2 types of sweat glands, where are they located, and how do they differ in function?

Eccrine glands - Open via duct to sweat pores on the skin's surface; Produce acidic sweat; Water, salts, vitamin C, traces of metabolic waste; Function in body temperature regulation Apocrine glands - Ducts empty into hair follicles in the armpit and genitals; Begin to function at puberty; Release sweat that also contains fatty acids and proteins (milky or yellowish color); Play a minimal role in body temperature regulation

What type of tissue is each of the layers of skin made up of? Epidermis? Dermis? and Hypodermis (technically not a layer of the skin)?

Epidermis is composed of keratinized stratified squamous epithelium Dermis is mostly dense (fibrous) connective tissue Hypodermis (subcutaneous layer) is not technically part of the integumentary system and is composed mostly of adipose tissue

What are the types of burns that one could endure and what are the characteristics of each?

First-degree burn (superficial burn) - Only epidermis is damaged - Skin is red and swollen Second-degree burn (partial-thickness burn) - Epidermis and superficial part of dermis are damaged - Skin is red, painful, and blistered - Regrowth of the epithelium can occur Third-degree burn (full-thickness burn) - Destroys epidermis and dermis; burned area is painless - Requires skin grafts, as regeneration is not possible - Burned area is blanched (gray-white) or black Fourth-degree burn (full-thickness burn) - Extends into deeper tissues (bone, muscle, tendons) - Appears dry and leathery - Requires surgery and grafting - May require amputation

What are the functions of the integumentary system and what does the integumentary system consist of?

Functions: Insulates and cushion deeper body organs Protects the entire body from: Mechanical damage (bumps and cuts) (keratin toughens cells, fat cushions, pressure and pain receptors alert NS) Chemical damage (acids and bases) (impermeable keratinized cells and pain receptors) Thermal damage (heat or cold) (receptors) Ultraviolet (UV) radiation (sunlight) (melanin) Microbes (bacteria) (barrier, phagocytes, skin secretions) Desiccation (drying out) (contains water resistant glycolipid and keratin) 3. Aids in loss or retention of body heat as controlled by the nervous system 4. Aids in excretion of urea and uric acid 5. Synthesizes vitamin D by converting cholesterol to vitamin D Consists of : Skin (cutaneous membrane) Skin appendages · Sweat glands (exocrine glands) · Oil glands (exocrine glands) · Hair · Nails

. What is a hair follicle, hair shaft, and arrector pili muscles? Where are they located?

Hair Follicle = is a structure of the skin that encloses the hair where the hair root is found Hair Shaft = the part of the hair that projects from the surface of the scalp or skin; this part of the hair is dead keratinized cells. Arrector pili muscle = tiny muscles that attach to the base of a hair follicle at one end and to dermal tissue on the other end. In order to generate heat when the body is cold, the arrector pili muscles contract all at once, causing the hair to "stand up straight" ("goosebumps") on the skin.

Describe the parts of a hair. Is this living tissue?

Hairs are found over the entire body surface, except for the palms of the hands, the soles of the feet, parts of the external genitalia, the nipples, and the lips. A hair, enclosed in a hair follicle, is also an epithelial structure. The part of the hair enclosed within the follicle is called the root; the portion projecting from the skin is the shaft. The hair is formed by mitosis of the germinal epithelial cells at the base of the follicle (the hair bulb). As the daughter cells are pushed away from the growing region, they become keratinized and die; thus, the bulk of the hair shaft, like the bulk of the epidermis, is dead material. A hair consists of a central region (medulla) surrounded first by the cortex and then by a protective cuticle.

What are some developmental issues with the skin? What problems do babies, teens, and older people face with possible skin issues.

In youth, skin is thick, resilient, and well hydrated; With aging, skin loses elasticity and thins; Skin cancer is a major threat to skin exposed to excessive sunlight;; both are genetically determined Babies: Lanugo, a downy hair, covers the body by the fifth or sixth month of fetal development but disappears by birth Vernix caseosa, an oily covering, is apparent at birth Milia, small white spots, are common at birth and disappear by the third week Teens: Acne may appear during adolescence Older people: Balding and/or graying occurs with aging

What is keratin, what is it produced by, and what is its significance?

Keratin is a fibrous protein that makes up your hair, skin and nails. It is produced by Keratinocytes. It forms protective layers of the skin that help maintain water balance and help protect the body from outside environmental factors.

What is melanin, what is it produced by, and what is its significance? What layer of the epidermis are these types of cells found?

Melanin is a pigment produced by melanocytes; Melanocytes are mostly in the stratum basale of the epidermis; Color is yellow to brown to black; Melanin accumulates in membrane-bound granules called melanosomes; Amount of melanin produced causing darkening of the skin (tanning) depends upon genetics and exposure to sunlight

Describe the parts of the nails. Is this living tissue?

Nails - heavily keratinized, scalelike modifications of the epidermis; stratum basale extends beneath the nail bed, which is responsible for growth; these cells are living but the part of the nail that you clip is dead tissue; lack of pigment makes nails colorless Parts of a nail: Free edge, Body is the visible attached portion, Nail folds are skin folds that overlap the edges of the nail; the cuticle is the proximal edge; Root of nail is embedded in skin; Growth of the nail occurs from nail matrix; Lunule is the white crescent area located over the nail matrix

What are the layers of the dermis and what are the characteristics of each?

Papillary layer (upper dermal region) contain projections called dermal papillae; Indent the epidermis above; Many projections contain capillary loops, and others house pain and touch receptors; On palm and sole surfaces, papillae increase friction and gripping ability; Fingerprints and footprints are created by the dermal papillae; Reticular layer (deepest skin layer) - Blood vessels, Sweat and oil glands, and deep pressure receptors (lamellar corpuscles) are located in this layer; nourishes the epidermis by diffusion from capillaries originating from this layer

What are the layer of the epidermis and what are the characteristics of each?

Stratum basale - Deepest layer of epidermis; Lies next to dermis; Wavy borderline with thedermis anchors the two together; Cells undergoing mitosis; Daughter cells are pushed upward to become the more superficial layers; About a quarter of the cells in this stratum are the spidery, brown-to-black pigment-producing cells called melanocytes Stratum spinosum - is immediately superficial to the basal layer. Its cells appear spiky (hence their name) because as skin is prepared for histological examination, its cells shrink but their desmosomes hold tight. Cell division also occurs in this layer, but less often than in the basal layer. Cells in the basal and spiny layers are the only ones that receive adequate nourishment (via diffusion from the dermis). As their daughter cells are pushed away from the source of nutrition, they gradually die. Stratum granulosum - is named for the abundant granules in its cells. Some of these granules contain a waterproofing glycolipid that is secreted into the extracellular space. Others contain the subunits of keratin. At the upper border of this layer, the cells are beginning to die. Stratum lucidum (thick, hairless skin only) - is a thin translucent band of flattened dead keratinocytes. This layer is present only in thick skin, such as the palms of the hands and soles of the feet. Stratum corneum - Outermost superficial layer of epidermis; 20-30 cell layers of shingle-like dead cells are filled with keratin (protective protein prevents water loss from skin)

What is produced by the sebaceous glands? What is sebum and why is it necessary?

The sebaceous glands produce sebum. Sebum is an oily waxy substance responsible for keeping the skin soft and moist (which also makes adolescent skin oilier); kills bacteria on the skin's surface, keeps hair follicles moisturized

Why are the sebaceous and sweat glands classified as exocrine glands?

They release secretions to the skin's surface through ducts. An exocrine gland is a gland that secretes substances onto an epithelial surface by way of a duct.

What are the visceral and parietal layers referring to?

Visceral layer is referring to the serous membrane that surrounds and covers the organ directly. Parietal layer refers to the serous membrane that is covering the outside of the serous fluid that surrounds the visceral layer. See the water balloon example in slides. Both of these layers are SEROUS membranes. The pair that covers the heart is the pericardium The pair that covers the lungs is the pleura The pair that covers the abdominal cavity is the peritoneum

Papillary layer-

contain projections called dermal papillae; Indent the epidermis above; Many projections contain capillary loops, and others house pain and touch receptors; On palm and sole surfaces, papillae increase friction and gripping ability; Fingerprints and footprints are created by the dermal papillae;

Stratum spinosum-

is immediately superficial to the basal layer. Its cells appear spiky (hence their name) because as skin is prepared for histological examination, its cells shrink but their desmosomes hold tight. Cell division also occurs in this layer, but less often than in the basal layer. Cells in the basal and spiny layers are the only ones that receive adequate nourishment (via diffusion from the dermis). As their daughter cells are pushed away from the source of nutrition, they gradually die.

Stratum granulosum-

is named for the abundant granules in its cells. Some of these granules contain a waterproofing glycolipid that is secreted into the extracellular space. Others contain the subunits of keratin. At the upper border of this layer, the cells are beginning to die.

Synovial membranes-

loose areolar connective tissue only (no epithelial tissue); line fibrous capsules surrounding joints; line bursae; line tendon sheaths; secrete a lubricating fluid to cushion organs moving against each other during muscle activity