Integumentary System

How many layers of keratinocytes comprise the stratum granulosum?

3-5

Keratinocytes of the epidermis are usually present for about ________ weeks

4

The nail matrix is the

actively growing part of the nail

Protection (function of skin)

acts as a physical barrier to physical injury, trauma, bumps, and scrapes

Thinning of the hair on the scalp is called

alopecia

Squamous cell carcinoma (skin cancer)

arises from keratinocytes of stratum spinosum

Malignant melanoma (skin cancer)

arises from melanocytes, usually in a preexisting mole

Sebaceous (location)

associated with hair follicles over much of the skin

Apocrine (location)

axillary, anal, areolar, and pubic regions

Heat retention (function of hair)

blanket of thick hair on scalp

In the first step of wound healing, cut blood vessels release ________ into the wound

blood

In the second step of would helping, a ___________ forms

blood clot

Since there are no blood vessels in the epidermis, where does its supply of nutrients come from?

blood vessels in dermis

The net effect of vasoconstriction of the dermal blood vessels is shunting of __________ away from the _________ of the body

blood; periphery

Mammary (location)

breasts

Some cells in the epidermis produce cholecalciferol when exposed to UV radiation. This substance travels to the kidneys where it is transformed into ___________. The new substance is a hormone that promotes ____________ and phosphate absorption form ingested materials in the small intestine

calcitriol; calcium

In the first step of would healing, blood brings _________ proteins, ___________, numerous white blood cells, and antibodies to the site

clotting; platelets

In the dermis of the skin, __________ fibers impart tensile strength while __________ fibers allow some stretch and contraction in the dermis during normal movement

collagen; elastic

The specific orientation of __________ fibers bundles in the dermis is a result of the direction of applied ___________ during routine movements

collagen; stress

When the skin is stretched beyond its capacity, some __________ are torn and result in stretch marks which are called ___________

collagen; striae

Visual identification (function of hair)

color and density of hairs of scalp

The cells of a hair follicle's walls are organized into two principal concentric layers; an outer ________ tissue root sheath, which originates form the dermis, and an inner __________ tissue root sheath, which originates form the epidermis

connective; epithelial

Cold can result in good vessel ___________, in the dermis, to ___________ blood flow which allows the body to conserve heat

constriction; reduce

Nails are derived from the same type of cells that produce the stratum ___________ layer of the epidermis. The cells that form the nails are densely packed and filled with parallel fibers of hard __________ protein

corneum; keratin

Because an entire portion of skin has been lost, and water cannot be retained in the area, a major concern with third degree burns is

dehydration

In addition to keratinocytes, the stratum spinosum also contains another epidermal cell type called epidermal ____________ cells. theses cells are _________ cells that help fight the invasion of microbes

dendritic; immune

Dermis

dense irregular connective tissue

Nerve fibers in the skin monitor sensory receptors in the _________ and __________

dermis; epidermis

Epidermal derivatives are located in the __________ and may project through the ____________ to the surface. The exposed parts of nails and hair are composed of _________, keratinized cells

dermis; epidermis; dead

Merocrine sweat production __________ during the aging process

diminishes

Merocrine (location)

distributed throughout body

Ceruminous (function/secretion)

ear wax

Temperature regulation (function of skin)

influenced by vast capillary networks and sweat glands in the dermis

Subcutaneous layer of the dermis

is a layer of areolar and adipose connective tissue

Stratum lucidum

is seen only in thick skin (palms/soles of fee)

Stratum corneum

is the most superficial layer of epidermis

The cells of the stratum corner contain large amounts of the protein

keratin

Within the stratum granulosum begins a process called ___________ by which the keratinocytes fill up with protein

keratinization; keratin

The tissue type of the epidermis is

keratinized stratified squamous epithelium

Epidermis

keratinized, stratified squamous epithelium

The most numerous cells of the epidermis are __________ and the protein they produce is called __________

keratinocytes; keratin

Mesenchyme

layer of cells covering the developing embryonic epithelium

Periderm

layer of cells covering the developing embryonic epithelium

Stratum basale

layer of skin that contains keratinocytes, melanocytes, and tactile cells

Stratum granulosum

layer of skin that keratinization begins

Stratum spinosum

layer of skin that keratinocytes attached to neighbors by desmosomes

Sebaceous (function/secretion)

lipid material called sebum

In the third step of wound healing, ___________ within the wound begin to remove the clotted blood

macrophages

The most numerous and widely distributed sweat glands in the body are

merocrine sweat glands

Mammary (function/secretion)

milk to nourish offspring

Sensory reception (function of skin)

nerve endings that detect heat, cold, touch

The main function of melanin pigment is to protect the __________ of keratinocytes from UV radiation

nucleus

A fully keratinized cell is dead because it has neither a __________ nor _____________

nucleus; organelles

Chemical signal dispersal (function of hair)

pheromones on hairs

Cavernous hemangiomas, sometimes called _________ strains, involved large dermal _________ and may last a lifetime

port wine; blood vessels

The recreation produced by apocrine sweat glands is viscous, cloudy, and composed of _________ & _________ that are acted upon by bacteria, producing a distinct, noticeable odor

proteins; lipids

In the third step of wound healing, the cut blood vessels ___________ and grow in the wound

regenerate

Protection (function of hair)

scalp hair covers the scalp and shields it form sunburn and injury

The secretions of sebaceous glands, called __________ is usually deposited into a __________

sebum; hair follicle

Apocrine (function/secretion)

secretion influenced by hormones

After a stem cell divides in the stratum basale, the resulting daughter cell enters the stratum ___________ and it begins to lose its ability to ___________

spinosum; divide

The skin houses two types of general exocrine glands

sweat & sebaceous glands

The secretion from merocrine sweat glands are carried to the surface of the epidermis via __________. the secretions of apocrine sweat glands are carried into ____________

sweat ducts; hair follicles

Scattered among the cells of the stratum basale are cells that are sensitive to touch. These sensory cells are called

tactile cells

Differences in hair density are due primarily to differences in its

texture & pigmentation

Friction ridges assume the shapes of complex arches and whorls in _________ skin

thick

The delivery of drugs through the skin though the use of an adhesive patch is called

transdermal administration

The release of water vapor from sweat glands when we are not sweating is a process called ___________

transpiration

True or false: Regeneration in the skin replaces damaged or dead cells with the same cell type and restores organ function

true

True or false: The acidic pH of merocirne sweat helps prevent the growth of some pathogenic bacteria

true

Drugs are often injected into the subcutaneous layer because its extensive __________ network promotes rapid absorption

vascular

Many cells in the epidermis produce what when exposed to UV radiation

vitamin D3 & cholecalciferol

The substance that make sweat feel gritty are

water salts and urea

Vernix caseosa

waterproof protective covering composed of sebum and sloughed off cells

Description of the skin's form and function

- barrier - self renewing - indicator of health

In the first step of wound healing, the blood brings what?

- clotting proteins - white blood cells - antibodies

The epidermis lacks what?

- collagen fibers - blood vessels - adipose tissue

Friction ridges are located on the skin in four regions of the body:

- fingers - palms - soles - toes

Normal skin color results from a combination of factors, mainly pigments called

- hemoglobin - melanin - carotene

During our lives, we produce three kinds of hair:

- lanugo (thin hair for fetus in last trimester) - vellus (hair at birth) - terminal (coarser, pigmented, longer),

The skin contains the following accessories:

- nails - hair follicles - sweat glands - sebaceous glands

Basal cell carcinoma (skin cancer)

- originates in stratum basale - most common type of skin cancer

Mammary gland only become functional in

- pregnant females - lactating females

Sensory receptors of the skin are

- pressure - vibration - cold

The main functions of the subcutaneous layer are

- provides thermal insulation - acts as an energy reservoir - protects the body

The major functions of merocrine sweat glands are

- secretion - protection - thermoregulation

In the tin and thick skin, the layers that contain living cells are the

- stratum basale - stratum spinosum - stratum granulosum

Immune cells found in the epidermis are called

epidermal dendritic

Prevents water loss (function of skin)

epidermis is water resistant

Apocrine and merocrine sweat glands release their secretory products by the process of ________

exocytosis

Ceruminous (location)

external acoustic meatus

Sebaceous glands are most abundant on the _________ and __________

face;scalp

The replacement scar tissue is produced by ____________ and composed primarily of __________ fibers

fibroblasts; collagen

In the fourth step of wound healing, the process of _________ fills the gap with connective tissue

fibrosis

On wound healing, if regeneration is not possible, connective tissue ___________ occurs

fibrosis

Potential complications of a wound under repair include

fluid loss & infection

Merocrine (function/secretion)

function in thermoregulation and excretion

Sensory reception (function of hair)

hair root plexuses

Facial expression (function of hair)

hairs of eyebrows

The amount of melanin int he skin is determined by both

heredity & light exposure