The Integumentary System
Xerosis
"dry skin" a common complaint of older persons and almost anyone living in an arid climate
Which of the following is NOT a function of the integument?
conduction of electrical impulses ?????
Dandruff is caused by excessive shedding of cells from the outer layer of skin in the scalp. Thus, dandruff is composed of cells from which epidermal layer?
consists of cells from the stratum corneum
What happens when the arrestor pili muscle contracts?
contraction of the arrestor pili muscle pulls on the hair follicle, making the hair stand erect. The result is sometimes known as "goosebumps"
identify the orders of layers that piece of glass would puncture as it passes through the skin on the palm of the hand
corneum, lucidum, granulosum, spinosum, basale, papilae
what structure is deep to the epidermis and superficial to the dermis
hypodermis
Biopsy
the removal and examination of tissue from the body for the diagnosis of disease
What is the main role of Vitamin D3 produced in the skin?
uptake of calcium
Some criminals sand their fingertips to avoid leaving recognizable fingerprints. Would this practice permanently remove fingerprints? Why or why not?
Sanding the tips of the fingers will not permanently remove fingerprints. The ridges of fingerprints are formed in skin layers that are constantly regenerated, so these ridges will eventually reappear.
what term describes the combination of fibrin clots, fibroblasts, and the extensive network of capillaries in healing tissue?
The combination of fibrin clots, fibroblast, and the extensive network of capillaries in healing tissue is called granulation tissue
Pruritus
an irritating itching sensation, common in skin conditions such as psoriasis or dermatitis
which gland is responsible for odorous secretions concentrated in armpits and groin
apocrine sweat glands
Which of the following is a. bundle of smooth muscle cells that connects to each hair?
arrestor pili
To form an effective barrier that protects underlying tissues, the epithelial cells of the skin must hold onto one another and also be connected to the rest of the body. They do this with specialized cell junctions known as desmosomes and hemidesmosomes. Desmosomes lock together the plasma membranes of epithelial cells, forming the different strata of the epidermis. Hemidesmosomes firmly attach the deepest cells of the stratum basal to the extracellular basement membrane. What kind of specialized cell junction dermis the free diffusion of ions and small molecules between two cells?
gap junction
What substance makes nails hard?
keratin gives nails their strength
Where are the capillaries that supplies the epidermis located?
located in the papillary layer of the dermis, where they follow the contours of the epidermis-dermis boundary
What are the functions of sebaceous secretions?
lubricate and protect the keratin of the hair shaft, lubricate and condition the surrounding skin, and inhibit bacterial growth
the pale crescent or half-moon at the base of the nails is called the
lunula
Which of the following is a red-yellow or brown-black pigment produced in the epidermis
melanin
What role does the female integumentary system have in human reproduction?
specialized integumentary glands produce milk
In which of the epidermal layers are the cells undergoing mitosis
stratum basale
what is the deepest epidermal layer called?
stratum basale
A useful technique for long-term drug administration, called transdermal administration, involves putting a sticky, drug-containing patch over an area of thin skin. What epidermal layer is found in thick and NOT in thin skin?
stratum lucidum
List the two terms for the tissue that connects the dermis to underlying tissues?
subcutaneous layer or hypodermis
Where does nail growth take place?
occurs at the nail root, an epidermal fold that is not visible from the surface
The most superficial layer of the dermis is the
papillary layer
Identify the five layers of the epidermis
1.) stratum basale 2.) stratum spinous 3.) stratum granulosum 4.) stratum lucidum 5.) stratum coreneum
Older individuals do not tolerate summer heat as well as they did when they were young, and they are more prone to heat-related illnesses. What accounts for these changes?
As a person ages, the blood supply to the dermis decreases and merocrine sweat glands become less active. The changes make it more difficult for elderly people to cool themselves in hot weather.
Deodorants are used to mask the effects of secretions from which type of skin gland?
Deodorants are used to mask the odor of apocrine sweat glands secretions, which contain several kinds of organic compounds that have an odor or produce an odor when metabolized by skin bacteria
If a burn on the forearm destroys the epidermis and the deep dermis and then heals, will hair grow again In the affected area?
Even though hair is a structure derived from the dermis, the follicles are in the dermis. Where the epidermis and deep dermis are destroyed, new hair will not grow.
The skin provides a somewhat waterproof outer shell that helps the body retain water. However, one of the integument's other functions involves losing water. Which function is that?
Heat loss through sweating
Explain the relationship between sunlight exposure and vitamin D3 synthesis.
In the presence of ultraviolet radiation in sunlight, epidermal cells in the stratum spinous and stratum basalt convert a cholesterol-related steroid into vitamin D3
The protein that contributes to many of the skin's protective qualities is called
Keratin
Cavernous hemangioma
a mass of large blood vessels that can occur in the skin or other organs in the body; a "port wine stain" birthmark generally lasts a lifetime
Epidermal cells synthesize this vitamin when exposed to sunlight
Vitamin D3
Why does exposure to sunlight or sunlamps darken skin?
When exposed to ultraviolet radiation in sunlight or tanning lamps, melanocytes in the epidermis (or dermis) synthesize the pigment melanin, darkening the skin
Why does skin of a light-skinned person appear red during exercise in hot weather?
When skin gets warm, arriving oxygenated blood is diverted to superficial blood vessels to eliminate heat. The oxygenated blood imparts a reddish coloration to the skin
Why does hair turn gray or white with age?
With advancing age, melanocyte activity decreases, leading to gray or white hair.
Describe the location of the dermis?
a connective tissue layer lies immediately deep to the epidermis
Describe a typical strand of hair
a keratinous strand produced by epithelial cells of a hair follicle
Describe the subcutaneous layer?
a layer of areolar tissue containing many adipose (fat) cells, which lies below the dermis. It is not considered a part of the integument, but it is important in stabilizing the position of the skin in relation underlying tissues
Ulcer
a localized shedding of an epithelium
What is the most common skin cancer?
basal cell carcinoma
Recall that the epidermis is a stratified squamous epithelium and is found where mechanical stresses are severe. Such an epithelium provides physical protection against abrasion and chemical attack and helps keep microorganisms outside the body. What is the name of the structure that connects epithelia cells to underlying connective tissue?
basement membrane
Why can skin regenerate effectively even after considerable damage?
because stem cells persist in both the epithelial and connective tissue components of skin. When injury occurs, cells of the stratum basal replace epithelial cells while connective tissue stem cells replace cells lost from the dermis
Name the two pigments in the epidermis
carotene and melanin -carotene=an orange-yellow pigment -melanin=a brown, yellow-brown, or black pigment
Glands that are located in the passageway of the external ear are called ________ glands
ceruminous
Lesions
changes in tissue structure caused by injury or disease
The integumentary system protects deeper structures from which of the following
chemicals, infections, dehydration, physical damage from impacts
Through which mechanism does perspiration function in cooling the body?
evaporation
recall the exocrine glands secrete their products onto an epithelial surface. These secretions reach the surface either directly or through tubular ducts that open onto the surface of the skin, or onto an epithelium lining, an internal passageway that connects to the exterior. Exocrine glands can be classified according to their mode of secretion or type of secretion. Which type of exocrine secretion is characterized by the entire cell becoming packed with secretory vesicles and then bursting, releasing the secretion but killing the cell?
holocrine
The loose connective tissue that separates the integument from deeper tissues and organs is called the
hypodermis
Which of the following contains large quantities of adipose tissue, blood vessels, and nerve cells, but does not contain any vital organs?
hypodermis???
Dermatitis is an inflammation of the skin that mainly involves the papillary layer of the dermis. The inflammation typically begins in an area of the skin exposed to infection or irritation by chemicals, radiation, or mechanical stimuli, such as scratching. What is the name of the other, deeper layer of the dermis?
reticular layer
Identify two types of exocrine glands found in the skin.
sebaceous (oil) and sweat glands
which of the following is an oil gland that secretes into hair follicles?
sebaceous gland
Burns are relatively common injuries that result from skin exposure to heat, friction, radiation, electrical shock, or strong chemical agents. When evaluating burns in a clinical setting, two key factors must be determined: the depth of the burn and the percentage of skin surface area that has been burned. What kind of burn is characterized by blistering?
second degree burn