Other Subject
science
anatomy
physiology
system
integumentary
accessory structure of skin
layers of the skin
skin
skin disorders
intergumentary system
Stratum Basale
Accessory Structures of the Skin
Calluses
Hair
nails
Stratum Granulosum
Stratum Spinosum
Stratum Lucidum
Stratum Corneum
Dermis
Papillary Layer
Reticular Layer
Hypodermis
Pigmentation
University/Undergrad
onset of puberty
It is most common along with the ________ due to associated hormonal changes, but can also occur in infants and continue into adulthood.
excrete sebum
They generate and ________, a mixture of lipids, onto the skin surface, thereby naturally lubricating the dry and dead layer of keratinized cells of the stratum corneum, keeping it pliable.
skin cancers
It is the most fatal of all ________, as it is highly metastatic and can be difficult to detect before it has spread to other organs.
pale skin
Dark- skinned individuals produce more melanin than those with ________.
Skin
________ and its underlying tissue can be affected by excessive pressure.
Mutations
________ can lead to uncontrolled cell proliferation and malignancies.
fourth degree burn
A(n) ________ is even more severe, affecting the underlying muscle and bone.
second degree burn
A(n) ________ goes deeper and affects both the epidermis and a portion of the dermis.
keratinocyte
is a cell that manufactures and stores the protein keratin.
Keratin
is an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties.
absence of sun exposure
The ________ can lead to a lack of vitamin D in the body, leading to a condition called rickets, a painful condition in children where the bones are misshapen due to a lack of calcium, causing bowleggedness.
stratum basale
(also called the stratum germinativum) is the deepest epidermal layer and attaches the epidermis to the basal lamina, below which lie the layers of the dermis.
dermal papilla
(plural = dermal papillae) is found in the superficial portion of the dermis.
The skin is composed of two main layers
the epidermis, made of closely packed epithelial cells, and the dermis, made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, and other structures
basal cell
is a cuboidal-shaped stem cell that is a precursor of the keratinocytes of the epidermis.
melanocyte
a cell that produces the pigment melanin.
Melanin
gives hair and skin its color, and also helps protect the living cells of the epidermis from ultraviolet (UV) radiation damage.
stratum spinosum
is spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome.
Langerhans cell
Interspersed among the keratinocytes of this layer is a type of dendritic cell called the
stratum granulosum
has a grainy appearance due to further changes to the keratinocytes as they are pushed from the stratum spinosum.
keratohyalin
which accumulates as lamellar granules within the cells.
stratum lucidum
is a smooth, seemingly translucent layer of the epidermis located just above the stratum granulosum and below the stratum corneum.
eleiden
a clear protein rich in lipids, derived from keratohyalin, which gives these cells their transparent (i.e., lucid) appearance and provides a barrier to water.
stratum corneum
is the most superficial layer of the epidermis and is the layer exposed to the outside environment.
dermis
might be considered the ācoreā of the integumentary system (derma- = āskinā), as distinct from the epidermis (epi- = āuponā or āoverā) and hypodermis (hypo- = ābelowā).
papillary layer
is made of loose, areolar connective tissue, which means the collagen and elastin fibers of this layer form a loose mesh.
Elastin fibers
provide some elasticity to the skin, enabling movement.
hypodermis
(also called the subcutaneous layer or superficial fascia) is a layer directly below the dermis and serves to connect the skin to the underlying fascia (fibrous tissue) of the bones and muscles.
melanosome
The melanin is transferred into the keratinocytes via a cellular vesicle called a
hair follicle
Strands of hair originate in an epidermal penetration of the dermis called the
hair shaft
is the part of the hair not anchored to the follicle, and much of this is exposed at the skinās surface.
hair root
The rest of the hair, which is anchored in the follicle, lies below the surface of the skin and is referred to as the
hair matrix
The hair root ends deep in the dermis at the hair bulb, and includes a layer of mitotically active basal cells called the
hair papilla
which is made of connective tissue and contains blood capillaries and nerve endings from the dermis
internal root sheath
The cells of the ___ surround the root of the growing hair and extend just up to the hair shaft.
external root sheath
The ___, which is an extension of the epidermis, encloses the hair root.
glassy membrane
is a thick, clear connective tissue sheath covering the hair root, connecting it to the tissue of the dermis.
arrector pili
Each hair root is connected to a smooth muscle called the
anagen phase
, during which cells divide rapidly at the root of the hair, pushing the hair shaft up and out.
catagen phase
lasts only 2 to 3 weeks, and marks a transition from the hair follicleās active growth.
telogen phase
, the hair follicle is at rest and no new growth occurs.
nail body
The is formed on the nail bed
eponychium
The nail fold that meets the proximal end of the nail body forms the nail cuticle, also called the
lunula
The nail bed is rich in blood vessels, making it appear pink, except at the base, where a thick layer of epithelium over the nail matrix forms a crescent-shaped region called the___(the ālittle moonā).
hyponychium
The area beneath the free edge of the nail, furthest from the cuticle, is called the
eccrine sweat gland
is a type of gland that produces a hypotonic sweat for thermoregulation.
apocrine sweat gland
is usually associated with hair follicles in densely hairy areas, such as armpits and genital regions.
sebaceous gland
is a type of oil gland that is found all over the body and helps to lubricate and waterproof the skin and hair.
cholecalciferol
In the presence of sunlight, a form of vitamin D3 called *__*is synthesized from a derivative of the steroid cholesterol in the skin.
rickets
a painful condition in children where the bones are misshapen due to a lack of calcium, causing bowleggedness.
Basal cell carcinoma
is a form of cancer that affects the mitotically active stem cells in the stratum basale of the epidermis.
melanoma
is a cancer characterized by the uncontrolled growth of melanocytes, the pigment-producing cells in the epidermis.
Eczema
is an allergic reaction that manifests as dry, itchy patches of skin that resemble rashes.
Acne
is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back).
first-degree
is a superficial burn that affects only the epidermis.
second-degree
burn goes deeper and affects both the epidermis and a portion of the dermis.
third-degree
burn fully extends into the epidermis and dermis, destroying the tissue and affecting the nerve endings and sensory function
fourth-degree
burn is even more severe, affecting the underlying muscle and bone.
scar
is collagen-rich skin formed after the process of wound healing that differs from normal skin.
stretch mark
results when the dermis is stretched beyond its limits of elasticity, as the skin stretches to accommodate the excess pressure.
corn
is a specialized form of callus.