integumentary A&P & practice questions
the following events occur in the life of a keratinocyte. place them in chronological order starting with what happens firs and ending with what happens last
1 Stem cells divide to produce new keratinocytes. 2 Mitosis ceases as epidermal cells are pushed upward. 3 Keratinocytes flatten and produce waterproof bundles of keratin filaments. 4 Keratinocytes die. 5 Dead keratinocytes flake off the surface of the skin as dander.
the epidermis is composed of five cell types. match each type to its description
1. Stem cells-Undifferentiated cells that divide and give rise to keratinocytes. 2. Keratinocytes-Epidermal cells that produce keratin. 3. Melanocytes-Cells that produce the dark pigments that act as a UV shield. 4. Tactile cells-Sensory receptors for touch. 5. Dendritic cells- Immune cells that guards against pathogens that penetrate into the skin.
place these epidermal layers in order, starting with the most superficial layer at the top of the list and ending with deepest layer at the bottom
1. Stratum corneum 2. Stratum lucidum 3. Stratum granulosum 4. Stratum spinosum 5. Stratum basale
Place the three kinds of hair in the order from the thinnest (softest) hair to the thickest (coarsest) type of hair
1. lanugo 2. vellus 3. terminal hair
which of the following describes the composition of sweat
acidic solution containing urea, potassium, sodium chlorideand ammonia
thinning of the hair, or baldness is called
alopecia
most common type of skin cancser
basal cell carcinoma
which of the following are found in the dermis?
blood vessels, nerve endings, glands, fibers
which glands secrete a substance that combines with sebum to keep the eardrum protected and prevent foreign particles from entering the canal
ceruminous
which layer of the hair is made of layers of elongated keratnized cells
cortex
UV radiation may cause skin cancer by doing which of the following
damage DNA and disable protective tumor-suppressor genes in epidermal cells
which term refers to the wavy upward projections at the boundary of the dermis and epidermis?
dermal papilae
which structure nourishes the hair cells
dermal papilla
cells in the epidermis are nourished by blood vessels located in which of the following
dermis
oxygen and nutrients needed by the epidermal cells undergoing mitosis are acquired from blood vessels in which one of the following layers
dermis
which skin layer has the hair follicles and nail roots embedded in it
dermis
The term ________ describes the condition in which sweat is produced, causing noticeably wet skin during circulatory shock or exercise
diaphoresis
the appearance of the fingernails can be valuable in determining which of the following
dietary deficiencies, oxygen needs, medical diagnosis
which layers are involved in a second-degree burn
epidermis & part of the dermis
the skin is composed of which of the following
epidermis and dermis only
what are the two principal layers of the hair follicle
epithelial root sheath and connective tissue root sheath
name the narrow zone of dead skin that commonly overhangs the proximal end of the nail
eponychium
what is the mode of secretion for apocrine sweat glands
exocytosis
the skin is essential in sensing
external stimuli: injury, temperature, touch
The hairs of the _____ enhance facial expression and keep sweat out of the eyes
eyebrows
which stimuli commonly lead to the contraction of the piloerector muscles?
fear, cold, touch
tube-like structures within which hairs grow
follicles
fingerprints are caused by which of the following
friction ridges
eyelashes
function as a shield to protect the eyes from windblown debris with a quick blink
apocrine glands are concentrated in which areas of the body
groin and anal region, beard area, axillary region
The ________ ________ is a region of mitotically active cells that serves as the hair's growth center
hair matrix
Which are accessory organs of the integumentary system?
hair, nails, and cutaneous glands
which of the following are accessory organs (appendages) of skin
hair, nails, and cutaneous glands
birthmarks also called _____ are patches of skin discolored by benign tumor of blood capillaries
hemangiomas
another word for bruise, or mass of clotted blood showing through the skin
hematoma
The layer called _______ is located deep to dermis
hypodermis
The layer called the _________ is located deep to the dermis and is not part of the skin
hypodermis
which term refers to the area of epidermis that covers the nail bed
hyponychium
which of the following are examples of when you would typically observe cyanosis?
in drowning victim, patient with emphysema, under cold conditions
dermatology
is the branch of medicine specializing in the care and treatment of the skin. The skin also is the most vulnerable of our organs, exposed to radiation, trauma, infection, and injurious chemicals. Consequently, it needs and receives more medical attention than any other organ system.
which of the following is true about red hair as compared to dark hair
it contains more pheomelanin than eumelanin
A condition called __________ is a yellowing of the skin and whites of the eyes resulting from high levels of bilirubin in the blood
jaundice
a protein produced in the cells of the epidermis that improves its durability and resistance to infection
keratin
the white crescent area located over the nail matrix is called the
lunule
the stratum basale contains which of the following
macrophages to protect the body, the colored pigment melanin, actively dividing cells
the acid ____________ is the protective film that gives skin its slight acidity
mantle
which compound is the primary determinant of skin color
melanin
melanoma is a type of skin cancer that arises from which kind of cell
melanocytes
which cells produce the brown to black pigment found in skin
melanocytes
which type of sweat glands are the most abundant glands in the body numbering 3-4 million in the adult skin?
merocrine
sweat glands that have a relatively narrow lumen and a duct that opens by way of a pore on the skin surface are called
merocrine sweat glands
elevated patches of skin that are harmless and sometimes regarded as "beauty marks"
moles
which term refers to the portion of a fingernail or toenail that is attached to the finger
nail body
where is hair found on the body
on the scalp and skin of the arms and legs
In which areas of the body is the dermis the thickest
palms and soles
which describes a first degree burn
reddening of the skin; involvement of the epidermis only
deepest layer of the dermis
reticular layer
which of the following is the only area with hair that is thick enough to retain heat
scalp
oil-producing glands associated with hair follicles are called
sebaceous glands
the substane that is released by seabaceous glands and that helps prevents skin and hair from becoming dry and brittle is called
sebum
the part of a hair that projects from the surface of the scalp or skin is called the hair
shaft
due to extensive structural damage, third degree burns are more likely to require which of the following, as compared to other types of burns
skin grafts
a single layer of cuboidal stem cells and melanocytes resting on a basement membrane
stratum basale
fingernails and toenails are derivatives of which epidermal layer?
stratum corneum
which epidermal layers contain dendritic cells
stratum spinosum and stratum granulosum
which of the following are sensory cells that respond to light touch?
tactile cells
which type of hair is the predominant form of hair found on the scalp
terminal
which type of hair includes scalp hair
terminal hair
which type of hair includes scalp hair?
terminal hair
List the features of skin that minimize bacteria and fungi growth during an infection
the acid mantle inhibits microbial growth, the dryness of the skin inhibits microbial growth
structures that guard the nostrils and ear canals, preventing particles from entering.
vibrissae or guard hairs
the skin functions as an important barrier to which of the following
water, ultraviolet radiation, microorganisms
match the hair-type with the cross-sectional shape of the hair
wavy-oval straight-round tight curl- flat
You walk around outside for less than an hour. You look at your hand and forearm and notice they are slightly red, but not blistered. What can you conclude?
you have a first degree burn
match each type of cutaneous gland with its product
Sudoriferous gland-sweat Sebaceous gland-oily secretions Ceruminous gland-earwax Mammary gland-milk
which of the following are functions of the skin?
Vitamin D synthesis, thermoregulation, sensory reception
the majority of cells found in the epidermis are which of the following
Keratinocytes
HYPODERMIS
Location: Deep to skin Description: Layer of loose areolar connective and adipose tissue Contains cutaneous nerves and blood vessels, and glands (sweat and sebaceous) Contains lamellated (Pacinian) corpuscle (pressure receptor) Contains portions of hair follicles associated with thin skin Function: Fat storage Thermal regulation Permits movement of skin Also known as: Subcutaneous tissue or superficial fascia
hypodermis. merocrine sweat gland. low mag
Location: Deep to skin Description: Layer of loose areolar connective and adipose tissue Contains cutaneous nerves and blood vessels, and glands (sweat and sebaceous) Contains lamellated (Pacinian) corpuscle (pressure receptor) Contains portions of hair follicles associated with thin skin Function: Fat storage Thermal regulation Permits movement of skin Also known as: Subcutaneous tissue or superficial fascia
hair follicle - thin skin low mag
Location: Dermis May extend into hypodermis Description: Tube that surrounds hair root Courses obliquely through dermis Two coats: epidermic (inner) and dermic (outer) Characteristic parts include: dermal papilla bulb, hair shaft, cuticle layer, internal follicular sheath, and external follicular sheath Associated with hair receptors and arrector muscle of the hair Function: Hair formation and growth Comment: Hair follicle develops as invagination from epidermis Follicle associated with a sebaceous gland, an arrector muscle of the hair, and an apocrine gland (in axilla and anogenital regions) Apocrine glands release part of apical cytoplasm with secretion Arrector muscle of the hair also known as arrector pili (piloerector) muscle
Duct of merocrine sweat gland (thick skin/low mag)
Location: Dermis and epidermis of skin Description: Lined by stratified cuboidal epithelium Has spiral course through dermis and epidermis from secretory part of gland Cells of duct epithelium are smaller and duct has a smaller lumen than secretory part of gland Comment: Sweat from merocrine gland is a nonviscous, hypotonic watery secretion
duct of sebaceous gland- thin skin low mag
Location: Dermis and epidermis of thin skin Description: Short passage between secretory part of gland and hair follicle Lined by stratified squamous epithelium that is continuous with external root sheath of hair Most frequently opens into upper portion of hair follicle May open directly on skin surface of glans penis, clitoris, and lips Function: Release of sebum into hair follicle or onto skin surface Comment: Sebum is oily substance produced by sebaceous glands
merocrine sweat gland. low mag
Location: Dermis and hypodermis of skin Description: Simple, coiled, tubular gland Secretory part of gland composed of simple cuboidal epithelium Duct opens directly on surface of skin at sweat pore Innervated by cholinergic nerve fibers Function: Production and release of non-viscous, hypotonic, watery secretion known as sweat Plays a major role in temperature regulation through cooling that results from evaporation of sweat from body surface Comment: Most numerous and widely distributed sweat glands in the body Palms, soles, and forehead have highest number of glands per square centimeter Some merocrine glands also called eccrine glands
arrector pili m. sebaceous gland. low mag
Location: Dermis of thin skin Description: Bundles of smooth muscle fibers Stretches obliquely from papillary layer of dermis to hair follicle Innervated by adrenergic nerve fibers Function: Contraction causes hair to stand in more vertical position (hair "stands on end") Elevates epidermis around opening of hair follicle ("goose bumps") Assists in secretion from sebaceous gland
cortex of hair, medium mag
Location: Hair Description: Located external to medulla (core) of hair Contains several layers of compact, flattened cells Cells undergo differentiation into keratin-filled cells Function: Primary source of hard keratin for hair Hair stiffness related to hard keratin Comment: Layers of hair include (deep to superficial): medulla (if present), cortex, and cuticle
hair matrix medium mag
Location: Hair bulb Description: Surrounds dermal papilla of hair bulb Scattered melanocytes present in matrix Function: Zone of dividing cells that give rise to all layers of hair and hair follicle Division and proliferation of cells in matrix account for hair growth Comment: Hair color determined by amount of melanin pigment synthesized by melanocytes in hair matrix
external root sheath high mag
Location: Hair follicle Description: Downgrowth of epidermis that forms external layer of hair follicle At skin surface composed of all layers of epidermis Thinner at dermal papilla, where it is composed only of cells corresponding to stratum basale of epidermis Function: Support for hair production and growth
internal root sheath high mag
Location: Hair follicle Description: Multicellular sheath that surrounds hair Extends around inferior part of hair Separates hair from external root sheath Comprised of soft keratin Function: Support for hair production and growth
differentiation zone of hair medium mag
Location: Hair root Description: Zone of dividing cells in core of hair root Function: Site for differentiation of cells in hair root
dermal papilla of hair bulb - high mag
Location: Inferior part of hair follicle (base of hair bulb) Description: Invagination of loose connective tissue Contains capillary network Function: Blood supply for hair follicle Comment: Damage to dermal papilla results in death of hair follicle
Dermal Papilla (thick skin, low mag)
Location: Interface between dermis and epidermis Description: Projection of papillary (external) layer of dermis Forms core of epidermal ridge Numerous and often branched Contains capillary loops Function: Provides nourishment to avascular epidermis Provides fingerprints for grasping objects
epithelium of apocrine sweat gland low mag
Location: Secretory part of apocrine sweat gland Description: Simple cuboidal cells form secretory part of apocrine sweat gland Myoepithelial cells underlie cuboidal cells and line basement membrane of gland Function: Production of viscous secretion (sweat) released into hair follicles in axilla, around areola of nipple, and anal region Comment: Secretory products are odorless when released but when metabolized by bacteria on skin creates distinctive odor
Stratum Basale (thick skin/low mag)
Location: Skin Deepest layer of epidermis Description: Single layer of columnar or high cuboidal cells resting on basement membrane Keratinocyte is predominant cell Also contains melanocytes, Merkel cells (touch receptors), and stem cells Function: Keratinocytes undergo mitosis, producing stem cells and cells that migrate into stratum spinosum Also known as: Basal layer or stratum germinativum Comment: Cells in stratum basale and stratum spinosum responsible for turnover of epidermal keratinocytes Melanocytes of this layer produce melanin, a natural sunscreen
sebaceous gland and duct- low mag
Location: Skin Description: Simple, saccular holocrine gland Secretory part lies in dermis Duct opens into hair follicle or onto skin surface Function: Secrete sebum (oily substance) Lubricate and waterproof hair shaft Comment: Not found in skin of palms (hands) or soles (feet) Holocrine glands produce secretion through fatty degeneration of cells in secretory part of gland
sebaceous gland- thin skin low mag
Location: Skin Description: Simple, saccular holocrine gland Secretory part lies in dermis Duct opens into hair follicle or onto skin surface Function: Secrete sebum (oily substance) Lubricate and waterproof hair shaft Comment: Not found in skin of palms (hands) or soles (feet) Holocrine glands produce secretion through fatty degeneration of cells in secretory part of gland
stratum spinosum (thick skin/low mag)
Location: Skin Epidermis, between stratum basale and stratum granulosum Description: Many layers of keratinocytes Deepest cells can divide Cells firmly attached to each other by desmosomes (cell junctions) Also contains dendritic (Langerhans) cells Function: Helps maintain physical strength of epidermis Helps maintain barrier to infectious agents and harmful substances Also known as: Prickle cell layer Comment: Cells in stratum basale and stratum spinosum responsible for turnover of epidermal keratinocytes
stratum granulosum thick skin low mag
Location: Skin Epidermis, between stratum spinosum and stratum lucidum Description: Three to five layers of flattened keratinocytes Keratinocytes contain dark staining keratohyalin granules (precursor of keratin) Nuclei of keratinocytes in various stages of degeneration Function: Protection for deeper layers Also known as: Granular layer Comment: Not a distinct layer in thin skin
stratum corneum thick skin high mag
Location: Skin Outermost layer of epidermis Description: Up to 30 layers of cornified, dead cells Dead cells contain keratin Function: Creates barrier to fluids\Also known as: Keratin layer Comment: Cells sloughed (shed) from surface and continually replaced from deeper layers Sloughed cells form major component of household "dust" Latin: cornu = horn
HAIR
Location: Thin skin Description: Accessory organ of skin Fine, keratinized filament Grows from oblique tube in skin called hair follicle Each hair has three zones: bulb, root, and shaft Projects from epidermal surface (length varies by body region) Usually pigmented (hair color due to melanin pigment granules in hair cortex) Function: Protection (e.g., from sunburn) Heat retention (esp. on scalp) Cutaneous sensation Dispersion of chemical signals Facial recognition/visual identification Comment: Hair not found in thick skin of palms (hands) or soles (feet) Genetic and hormonal factors determine body hair distribution Single hair also known as pilus (plural, pili)
apocrine sweat gland. low mag
Location: Thin skin of axilla, areola of nipple, and anal region Embedded in dermis and hypodermis Description: Simple coiled tubular gland with large lumen Secretory part composed of simple cuboidal epithelium Duct opens into hair follicle usually just superficial to opening of sebaceous gland duct Innervated by adrenergic nerve fibers Function: Production and secretion by exocytosis of viscous substance known as sweat Sweat from apocrine glands contains protein, carbohydrate, ammonia, lipid, and other organic substances Production and secretion of sweat is influenced by hormones Comment: Apocrine glands become functional at puberty Cerminous gland (in external auditory meatus) and glands of Moll (in margins of eyelids) are specialized apocrine glands Lumen of apocrine sweat gland much larger than lumen of merocrine sweat gland
DERMIS
Location: Skin (between epidermis and hypodermis) Description: Two layers: papillary (superficial), composed of areolar connective tissue; and reticular (deep), composed of dense irregular connective tissue Contains appendages of skin: hair follicles and glands (sweat and sebaceous) Contains sensory nerve endings and dense network of blood and lymphatic vessels Includes part of hair follicle (which develops as invagination from epidermis) Function: Supports epidermis Dense concentration of collagen and elastin gives skin strength Receives general sensory stimuli (pain, touch, and temperature) via nerve endings and specialized receptors Regulates body temperature
EPIDERMIS
Location: Skin (superficial to dermis Description: Keratinized stratified squamous epithelium of variable thickness Avascular Major cell type is keratinocyte Thick skin has five layers (superficial to deep): stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale Thin skin has four layers (stratum lucidum is missing) Cells of stratum lucidum and stratum corneum lack nuclei Thin skin has four layers (stratum lucidum is missing) Cells of stratum lucidum and stratum corneum lack nuclei Function: Physical barrier Protection of underlying structures Comment: Also contains stem cells, melanocytes, Merkel cells, and dendritic cells Depends on underlying dermis for nutrients (i.e., vascular supply)
Name the common types of hemangioma.
Port-wine, cavernous, capillary
during the process of thermoregulation, the body surface temperature is monitored by which of the following types of receptors
thermoreceptors
which of the following best describes the function of ceruminous gland secretions
they waterproof the ear canal, and coats the guard hairs of the ear
categorize the following body parts according to whether they are covered with thick skin or thin skin
thick: soles, palms, finger tips thin: forearms, eyelids, stomach, back
the hair type called _____ constitutes about two-thirds of the hair in women and one-tenth of the hair in men
vellus
