Integumentary system
In what important way does a freckle differ from a nevus?
A freckle is an area of excessive melanocyte activity and a nevus is caused by an increase in melanocyte numbers.
Since there are no blood vessels in the epidermis, where does its supply of nutrients come from?
Blood vessels in dermis
Papillary layer
Composed of areolar connective tissue; contains dermal papillae
Stratum basale
Contains keratinocytes, melanocytes, and tactile cells
______ cells are derived from white blood cells that phagocytize pathogens in the epidermis.
Dendritic
Reticular layer
Dense irregular connective tissue surrounding blood vessels, hair follicles, nerves, sweat glands, and sebaceous glands
Stratum spinosum
Keratinocytes attached to neighbors by desmosomes
Stratum corneum
Most superficial layer of epidermis
Subcutaneous layer
Not considered part of the integument
Many cells in the epidermis produce cholecalciferol when exposed to ______.
UV light
Which is a usual treatment for first-degree burns?
applying cool compresses
Tactile cells ______.
are also called Merkel cells
The two types of connective tissue in the dermis are ______.
areolar and dense irregular
Extending from the dermal papillae to the mid-region of the hair follicles are thin ribbons of smooth muscle that are collectively called the ______ muscles.
arrector pili
Extending from the hair follicle to dermal papillae are muscles called _____.
arrector pili
There are no blood vessels in the epidermis. The term for lack of blood vessels is ______.
avascular
A hemangioma is a congenital anomaly that results in skin discoloration due to ______ that proliferate and form a benign tumor.
blood vessels
In the nails, the lunula appears whitish because a thickened underlying stratum basale obscures the underlying ______.
blood vessels
Body temperature is influenced by two structures located in the dermis, ______ and ______.
blood vessels, sweat glands
Each nail plate consists of a pinkish nail ______ and a distal whitish free ______.
body, edge
The three recognizable zones along the length of a hair are ______.
bulb, root, shaft
Some cells in the epidermis produce cholecalciferol. This substance travels to the kidneys where it is transformed into ______, also known as Vitamin D.
calcitriol
Calcitriol increases the absorption of ______ from the small intestine into the blood.
calcium and phosphate
There are two types of hemangiomas, ______ and ______.
capillary, cavernous
The main structural components of the reticular layer is primarily a network of ______ fibers that extend internally from the reticular layer of the dermis into the underlying subcutaneous layer.
collagen
Nails are derived from the same type of cells that produce the stratum ______ layer of the epidermis.
corneum
Another name for the skin is the ______ membrane.
cutaneous
The exposed parts of nails and hair are composed of ______, keratinized cells.
dead
Vasoconstriction means that the diameter of the vessels ______, so relatively ______ blood can travel through them.
decrease, less
The reticular layer of the dermis is ______.
deep to the papillary layer
Immune cells found in the epidermis are called epidermal ______.
dendritic cells
The connective tissue root sheath of hair originates from the ______.
dermis
Nerve fibers in the skin monitor sensory receptors in the ______.
dermis and epidermis
Epidermal accessory organs are located in the ______ and may project through the ______ to the surface of skin.
dermis, epidermis
The spiny appearance of stratum spinosum cells is primarily due to the tenacious nature of _____, which function to hold these non-dividing cells together.
desmosomes
When the body is too warm, the blood vessels in the dermis ______ increasing blood flow, which allows the heat from blood to dissipate through the skin.
dilate
The keratinocytes within stratum lucidum are flattened and filled with the protein ______, an intermediate product in the process of keratin maturation.
eleidin
The dermal papillae interlock with deep projections of the epidermis called ______
epidermal ridges
Second-degree burns involve the ______ and part of the ______.
epidermis, dermis
The skin is made up of two distinct layers, the _____ and the _____.
epidermis, dermis
There are two types of melanin, _________ and pheomelanin, together they produce various ratios of yellow, reddish, tan, brown, and black shades.
eumelanin
Ceruminous glands are modified sweat glands located only in the ______.
external ear canal
The connective tissue layers of the dermis contain cells called ______.
fiberblasts
Cerumen, together with tiny hairs along the ear canal, helps trap ______ and keeps them from reaching the eardrum.
foreign particles and small insects
Fingerprints are useful as a forensic tool because each individual has a unique pattern of ______.
friction ridges
In the layer of the epidermis called the stratum ______, the process of keratinization begins.
granulosum
The epidermis is avascular, which means it ______
has no blood vessels
The amount of melanin in the skin is determined by _____.
heredity and ultraviolet light exposure
Sebaceous glands are classified as ______ glands that discharge an oily, waxy secretion called ______.
holocrine, sebum
The subcutaneous layer is also known as the ______ or superficial fascia.
hypodermis
Vasodilation of the dermal blood vessels means that the diameter of the vessels ______, so relatively ______ blood can travel through them.
increases, more
Stratum granulosum
keratinization begins in this layer
Most cells of the stratum spinosum are ______.
keratinocytes
The cells of the epidermis that produce keratin are called ______.
keratinocytes
Skin is classified as either thick or thin based on two parameters. These are the number of ______ in the epidermis and the relative thickness of the epidermis, rather than the thickness of the entire integument.
layers
The whitish semilunar area of the proximal end of the nail body is called the ______.
lunula
Melanin is transferred in membrane-bound vesicles from _____ to keratinocytes in the stratum basale.
melanocytes
Pigment producing cells of the epidermis are ______.
melanocytes
The two types of sweat glands in the skin are ______ sweat glands and ______ sweat glands.
merocrine, apocrine
A nevus is commonly referred to as a ______. It is a harmless, localized growth of ______ forming cells.
mole, melanin
The nail plate covers a layer of epidermis that is called the ______.
nail bed
During the process of keratinization, ______ disintegrate and the cells start to die. Also their membranes become thicker and less permeable.
organelles
Melanosomes are transferred to keratinocytes in the stratum basale via the process of ______ or exocytosis.
phagocytosis
Cavernous hemangiomas, sometimes called ______ stains, involve large dermal ______ and may last a lifetime.
port wine, blood vessels
Two major functions of hair are _____.
protection and heat retention
The secretion produced by apocrine sweat glands is viscous, cloudy, and composed of ______ that are acted upon by bacteria, producing a distinct, noticeable odor.
proteins and lipids
The apocrine sweat glands become active and produce secretory product after ______.
puberty
Hemoglobin exhibits a ______ color.
red
The secretions of sebaceous glands, called ______ is usually deposited into a ______.
sebum, hair follicle
Stratum lucidum
seen only in thick skin
The skin is said to be ______ because some materials are able to pass through it.
selectively permeable
When compressed, tactile cells release chemicals that stimulate ______ endings in the dermis.
sensory nerve
Merocrine sweat glands are classified as ______ glands that release their secretion onto the surface of the skin.
simple, coiled, tubular
The layer of the skin from which most new epidermal cells are derived from is the ______.
stratum basale
The stratum granulosum is just superficial to the ______.
stratum spinosum
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
On many parts of the body, the components of the dermis include blood vessels, ______ glands, ______ glands, hair follicles, nail roots, sensory nerve endings, and smooth muscle tissue.
sweat, sebaceous
The major function of merocrine sweat glands is ______.
thermoregulation
The stratum lucidum is found only in ______.
thick skin
There are three main variations in the epidermis. These variations are ______, ______, and skin markings.
thickness, coloration
______ skin contains the following accessories: nails, hair follicles, sweat glands, and sebaceous glands.
thin
Tactile cells are sensitive to ______.
touch
Among the stimuli detected by the sensory receptors of the skin are ______.
touch pressure
Under normal conditions, some interstitial fluids slowly escape through the epidermis via a process called ______ water loss.
transepidermal
Metabolic regulation is a function of the integument.
true
Nails and hair are components of the integumentary system.
true
The epidermis exhibits variations among different body regions within a single individual, as well as differences between individuals.
true
The substances that make sweat feel gritty are ______.
waste
Carotene exhibits a ______ color.
yellow or orange
the epidermis of thin skin ranges in thickness from ______ millimeters to ______ millimeters thick
0.075, 0.150
The epidermis of thick skin ranges from 0.4mm to ______ mm thick.
0.6
Migration of a keratinocyte from the stratum basale to the stratum corneum takes about _____ weeks.
2
How many layers of keratinocytes comprise the stratum granulosum?
3-5
In first degree burns, the healing time averages about _____ days, and typically no scarring results.
3-5
The integument accounts for about _____% of the body weight.
8
