Integumentary system Flashcards
cutaneous
the skin
composed of a keratinized stratified squamous
epithelium
layer of connective tissue
(termed the dermis) upon which the epithelium rests
synovial
composed of extensive areas of areolar connective tissue bounded by a superficial layer of squamous or cuboidal epithelial cells that lack a basement membrane
synovial fluid that reduces friction in the joint cavity and distributes nutrients to the cartilage on the joint surfaces of the bone
Mucous
lines body passageways and compartments
that eventually open to the external environment; these include the digestive, respiratory, reproductive, and urinary tracts. Mucous membranes perform absorptive, protective, and/or secretory functions. A mucous membrane is composed of an epithelium and underlying connective tissue called the lamina propria. Often, it is covered with a thin layer of mucus derived from goblet cells, multicellular mucous glands, or both. The mucus prevents the underlying layer of cells from drying out (a process called desiccation), provides lubrication, and traps bacteria and foreign particles to prevent them from invading the body.
serous membrane
composed of a simple squamous epithelium called mesothelium and a thin underlying layer of loose connective tissue produce a thin, watery serous fluid Serous membranes are composed of two parts: a parietal layer that lines the body cavity and a visceral
layer that covers organs. The parietal and visceral layers are in close contact; a thin layer of serous fluid between them reduces the friction between their opposing surfaces
stratum basale
The deepest epidermal layer is the stratum basale
The stratum basale is dominated by
large keratinocyte stem cells, which divide to provide both replacement stem cells and new keratinocytes that replace the dead keratinocytes shed from the surface Their structure in these cells gives skin its strength and makes the epidermis almost waterproof.
Melanocytes, pigment granules, called melanosomes Tactile cells are few in number and found scattered among the cells within the stratum basale. Tactile cells are sensitive to touch, and when compressed
BASAL CELL CARCINOMA
Most common type of skin cancer
■ Least dangerous type because it seldom metastasizes
■ Originates in stratum basale
■ First appears as small, shiny elevation that enlarges and develops central depression with pearly edge
■ Usually occurs on face
■ Treated by surgical removal of lesion
SQUAMOUS CELL CARCINOMA
Arises from keratinocytes of stratum spinosum
■ Lesions usually appear on scalp, ears, lower lip, or back of hand
■ Early lesions are raised, reddened, scaly; later lesions form concave ulcers with elevated edges
■ Treated by early detection and surgical removal of lesion
■ May metastasize to other parts of the body
MALIGNANT MELANOMA
■ Most deadly type of skin cancer due to aggressive growth and metastasis
■ Arises from melanocytes, usually in a preexisting mole
■ Individuals at increased risk include those who have had severe sunburns, especially as children.
■ Characterized by change in mole diameter, color, shape of border, and symmetry
■ Survival rates improved by early detection and surgical removal of lesion.
■ Advanced cases (metastasis of disease) are difficult to cure and are treated with chemotherapy, interferon therapy,and radiation therapy.
stratum granulosum
three to five layers of keratinocytes superficial to the stratum spinosum. Within this stratum begins a process called keratinization, keratinocytes fill up with the protein
keratin. cells become thinner and flatter. Their membranes thicken and become less permeable. The nucleus and all organelles disintegrate,
and the cells start to die. Subsequently, the dehydrated material left within the cells forms a tightly interlocked layer of keratin fibers sandwiched between thickened phospholipid membranes
Stratum Lucidum
a thin, translucent region about two to three cell layers thick that is superficial to the stratum granulosum.
This stratum is found only in thick skin,
such as the palms of the hands and the soles of the feet
Stratum Corneum
most superficial layer of the epidermis
consists of about 20–30 layers of dead, scaly, interlocking keratinized cells called corneocytes. The dead cells are anucleate and tightly packed together
Stratum Spinosum
Each time a keratinocyte stem cell
in the stratum basale divides, the daughter cell that will differentiate into the new epidermal cell is pushed toward the external surface from the stratum basale. Once this new cell enters the stratum spinosum, the cell begins to differentiate into a nondividing, highly specialized
keratinocyte.
The nondividing keratinocytes in the stratum
spinosum attach to their neighbors by many intercellular junctions called desmosomes
arrector pili muscle
to pull hair muscle
The arrector pili is usually
stimulated in response to an emotional state, such as fear or rage, or exposure to cold temperatures. Upon stimulation, the arrector pili contracts, pulling on the follicles and elevating the hairs, to produce
“goose bumps.”
apocrine gland
Distributed in axillary, anal, areolar, and pubic regions
Produces viscous, complex secretion; secretion infl uenced by hormones; may act in signaling/communication
Merocrine glands
Distributed throughout body, except external genitalia,
nipples, and lips; especially prevalent on palms, soles,
and forehead
Produce nonviscous, watery secretion; controlled by nervous system; provide some antibacterial protection; function in thermoregulation and excretion; flush surface of epidermis
Sebaceous glands
Associated with hair follicles
Produce lipid material called sebum, which coats epidermis and shaft of hair; provide lubrication and antibacterial activity
Papillary layer
superficial region of the dermis directly adjacent to the epidermis. It is composed of areolar connective tissu The dermal papillae interlock with deep projections of epidermis called epidermal ridges
houses sensory receptorsthat continuously monitor
touch on the surface of the epidermis
Most common type of skin cancer
■ Least dangerous type because it seldom metastasizes
■ Originates in stratum basale
■ First appears as small, shiny elevation that enlarges and develops central depression with pearly edge
■ Usually occurs on face
■ Treated by surgical removal of lesion
BASAL CELL CARCINOMA
Arises from keratinocytes of stratum spinosum
■ Lesions usually appear on scalp, ears, lower lip, or back of hand
■ Early lesions are raised, reddened, scaly; later lesions form concave ulcers with elevated edges
■ Treated by early detection and surgical removal of lesion
■ May metastasize to other parts of the body
SQUAMOUS CELL CARCINOMA
■ Most deadly type of skin cancer due to aggressive growth and metastasis
■ Arises from melanocytes, usually in a preexisting mole
■ Individuals at increased risk include those who have had severe sunburns, especially as children.
■ Characterized by change in mole diameter, color, shape of border, and symmetry
■ Survival rates improved by early detection and surgical removal of lesion.
■ Advanced cases (metastasis of disease) are difficult to cure and are treated with chemotherapy, interferon therapy,and radiation therapy.
MALIGNANT MELANOMA
three to five layers of keratinocytes superficial to the stratum spinosum. Within this stratum begins a process called keratinization, keratinocytes fill up with the protein
keratin. cells become thinner and flatter. Their membranes thicken and become less permeable. The nucleus and all organelles disintegrate,
and the cells start to die. Subsequently, the dehydrated material left within the cells forms a tightly interlocked layer of keratin fibers sandwiched between thickened phospholipid membranes
stratum granulosum
most superficial layer of the epidermis
consists of about 20–30 layers of dead, scaly, interlocking keratinized cells called corneocytes. The dead cells are anucleate and tightly packed together
Stratum Corneum
Each time a keratinocyte stem cell
in the stratum basale divides, the daughter cell that will differentiate into the new epidermal cell is pushed toward the external surface from the stratum basale. Once this new cell enters the stratum spinosum, the cell begins to differentiate into a nondividing, highly specialized
keratinocyte.
The nondividing keratinocytes in the stratum
spinosum attach to their neighbors by many intercellular junctions called desmosomes
Stratum Spinosum
Distributed in axillary, anal, areolar, and pubic regions
Produces viscous, complex secretion; secretion infl uenced by hormones; may act in signaling/communication
apocrine gland
Distributed throughout body, except external genitalia,
nipples, and lips; especially prevalent on palms, soles,
and forehead
Produce nonviscous, watery secretion; controlled by nervous system; provide some antibacterial protection; function in thermoregulation and excretion; flush surface of epidermis
Merocrine glands
Associated with hair follicles
Produce lipid material called sebum, which coats epidermis and shaft of hair; provide lubrication and antibacterial activity
Sebaceous glands
superficial region of the dermis directly adjacent to the epidermis. It is composed of areolar connective tissu The dermal papillae interlock with deep projections of epidermis called epidermal ridges
houses sensory receptorsthat continuously monitor
touch on the surface of the epidermis
Papillary layer
