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