ch 6 skin
Match the structure with the labels on the given picture of skin.
A- hair follicle B- arrector pili muscle C- sebaceous gland D- apocrine sweat gland
Match the structures with the labels in the picture of the nail.
A- matrix B- root C- eponychium D- lunula E- body of nail
Match the letter with the epidermal strata.
A- stratum corneum B- stratum lucidum C- stratum granulosum D- stratum spinosum E- stratum Basale
The main function of melanin pigment is to protect the _____ of keratinocytes from UV radiation.
DNA
Match the type of gland with its secretion or function
apocrine- secrete proteins and lipids merocrine- function in thermoregulation and excretion sebaceous- lipid material called sebum
Match the type of gland with its location.
apocrine-axillary, anal, areolar, and pubic regions merocrine- distributed throughout the body sebaceous- associated with hair follicles over much of the skin ceruminous- external acoustic meatus mammary- breasts
Epidermal dendritic cells are found in which of the following strata? Choose all that apply.
granulosum and spinosum
During the process of keratinization, the cell's ______ and organelles disintegrate and cells start to die
nucleus
Hair is found almost everywhere on the body except the sides and ______ of the hands and fingers, the sides and _____ of the feet and toes, the lips, and portions of the external genitalia.
palms; palms
The main functions of the subcutaneous layer are which of the following?
protects the body provides thermal insulation acts as an energy reservoir
Migration of a keratinocyte from the stratum basale to the stratum corneum takes about _____ weeks. The dead, keratinized cells usually remain in the exposed stratum corneum layer for an additional _____ weeks. Overall, keratinocytes are present for about _____ month following their formation.
2 weeks, 2 weeks, 1 month
In first-degree burns, the healing time averages about ______ days, and typically no scarring results.
3-5
______ layers of keratinocytes comprise the stratum granulosum.
3-5
Keratinocytes of the epidermis are usually present for about ______ week(s).
4
In what important way does a freckle differ from a nevus?
A freckle is an area of excessive melanocyte activity/a nevus is caused by an increase in melanocyte numbers.
True or false: Regeneration in the skin replaces damaged or dead cells with the same cell type and restores organ function.
false
A mild sunburn with no blistering is an example of a ______-degree burn.
first
he cells of a hair follicle's walls are organized into two principal concentric layers: an outer ______ tissue root sheath and an inner ______ tissue root sheath.
connective; epithelial
The stratum ______ consists of about 20 to 30 layers of dead, scaly, interlocking keratinized cells.
corneum
There are four layers of cells in the epidermis of thin skin. From superficial to deep, these layers are stratum ______, stratum ______, stratum ______, and stratum basale.
corneum; granulosum; spinosum
As skin ages, collagen fibers in the dermis ______ in number and organization, and elastic fibers ______ their elasticity.
decrease; lose
The dermis is ______ to the epidermis and contains primarily ______.
deep; collagen fibers
When a person is severely burned, a primary danger is _______ because the individual has lost the protective skin barrier and water can escape from body tissues.
dehydration
In addition to keratinocytes, the stratum spinosum also contains another epidermal cell type called epidermal ______ cells that help to fight infection.
dendritic
Motile cells in the dermis are called ______ cells.
dendritic
The keratinocytes within stratum lucidum are flattened and filled with the protein ______, an intermediate product in the process of keratin maturation.
eledin
The most superficial layer of the integument is the ______.
epidermis
The two distinct layers of the integument consist of a layer of stratified squamous epithelium called the ______ and a deeper layer of areolar and dense irregular connective tissue called the ______.
epidermis; dermis
Sebaceous glands and sweat glands are types of ______ glands of skin.
exocrine
The subcutaneous layer is also known as the ______ or superficial fascia.
hypodermis
The cells of the stratum corneum contain large amounts of the protein ______.
keratin
Within the stratum, granulosum begins a process called ______.
keratinization
the most numerous cells of the epidermis are ______ and the protein they produce is called ______
keratinocytes, keratin
The first three strata of the epidermis consists of ______ keratinocytes and the most superficial strata contain ______ keratinocytes.
living; dead
In thick skin, there is an extra layer of epidermal cells. This layer is called the stratum ______.
lucidum
Scattered among the keratinocytes of the stratum basale are pigment-producing cells called ______.
melanocytes
The ultraviolet rays in sunlight are prevented from penetrating to the deeper dermis layer by specialized cells called ______.
melanocytes
When exposed to the sun, the ______ become more active and secrete a protein that gives the skin a tanned look.
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 connective tissue fibers of the ______ layer of the dermis are extensively interwoven with those of the ______ layer to stabilize the position of the skin and bind it to the underlying tissues.
reticular; subcutaneous
The hair follicle is an oblique tube that surrounds the hair ______.
root
Fibrous tissue is also known as ______ tissue.
scar
When compressed, tactile cells release chemicals that stimulate ______ endings in the dermis.
sensory nerve
After a stem cell divides in the stratum basale, the resulting daughter cell enters the stratum ______ and it begins to lose its ability to divide.
spinosum
Classify the tissue type of the epidermis: keratinized ______ epithelium.
stratified squamous
The layer of the skin from which most new epidermal cells are derived from is the ______.
stratum basale
The most superficial layer of the epidermis is the ______.
stratum corneum
The secretion from merocrine sweat glands is 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; oil
The skin houses two types of general exocrine glands, which are ______ glands and ______ glands.
sweat; sebacuous
Scattered among the cells of the stratum basale are cells that are sensitive to touch. These sensory cells are called ______.
tactile cells
The stratum lucidum is found only in ______.
thick skin
There are three main variations in the epidermis. These variations are ______, colorations, and skin markings.
thickness
The release of water vapor from sweat glands when we are not sweating is a process called
transpiration
True or false: The epidermis exhibits variations among different body regions within a single individual, as well as differences between individuals.
true
True or false: The reason the cells of the stratum spinosum have a spiny appearance when viewed under a microscope is due to shrinkage of the cytoplasm.
true
As facial skin ages, the skin tends to form ______ and becomes less ______.
wrinkles; resilient
