Chapter 5 Flashcards
rintegumentary system
organ system made up of skin, sweat, oil glands, hairs and nails. made of cutaneous membrane and accessory structures.
epidermis
region of skin, composed of keratinized stratified squamous epithelium, the outermost protective shield of the body. provides a barrier against bacteria as well as chemical and mechanical injuries
made of 4 distinct cell types (keratinocytes, melanocytesm dendritic cells and tactile cells)
and 5 types of layers (stratum basale, stratum spinosum, stratum granulosum, stratum lucidum and stratum croneum)
dermis
region of skin. made up organs and vessels. makes up the bulk of the skin. it is a tough layer made up of dense fibrous connective tissue. has a rich supply of nerve fibers, blood vessels and lymphatic vessels. 2 layers: papillary layer and reticular layer
hypodermis
subcataneous tissue located just below the dermis. not part of the skin. consists of adipose tissue and areolar connective tissues. it anchors the skin to the muscles and acts as a shock absorber and an insulator that reduces heat loss. also called superficial fascia. allows skin to move easily over the underlying muscles because of the loose connective tissue
keratinocytes
most common cell of the epidermis. produce keratin (fibrous protein that gives epidermis its protective properties and reduces water loss at the skin surface). arise from stratum basale layer. these undergo constant mitosis. these are dead when they reach the skin surface and milions of these rub off everyday. we get a new epidermis every 25-45 days
melanocytes
a cell of the epidermis. synthesize the pigment melanin. melanin accumulate on the superficial side of the keratinocyte nucleus and forms a pigment shield that protects the nucleus from UV radiation
dendritic cells
epidermis cell (a type of macrophage). arise from bone marrow and migrate to the epidermis. they ingest foreign substances and activate our immune system. kind of phagocyte. also called Langerhans cells. represent a link between the integumentary and the lymphoid systems. most abundant in stratum spinosum. engulf antigens and then present fragments of them to their own surfaces, where they can be recognized by T cells
tactile cells or merkel cells
epidermis cell. functions as a sensory receptor for touch
thick skin
refers only to epidermis. covers areas subject to abrasion (palms, fintertips, soles of feet). have 5 layers (from deep to superficial): stratum basale, stratum spinosum, stratum granulosum, stratum lucidum and stratum corneum.
(stratum lucidum is absent in thin skin)
stratum basale also called stratum germinativum
deepest epidermal layer. attached to underlying dermis. consists of a single row of stem cells that form keratinocytes. melanocytes are here too. undergoes constant mitosis to replace cells lost by abrasion. journey from this layer to surface is 25-45 days
stratum spinosum
layer of epidermis. several layers of keratinocytes unified by desosomes. contain thick intermediate filaments and dendritic cells
stratum granulosum
layer of epidermis. consists of 4 to 6 cell layers. process of keratinization begins (this is when cells fill up with the protein keratin). cells flatten and organelles deteriorate. the cytoplasm is full of keratohyalin granules and lamellar granules. plasma membrane of cells here thicken. cells above these are too far from dermis (which has nutrients) so cells above this die
stratum lucidum
epidermis layer located just above stratum granulosum. consistes of 2 or 3 layers dead keratinocytes
stratum corneum
outermostepidrmal layer. 20 to 30 cell layers thick. accounts for 75% of epidermal thickness. keratin and thick plasma membraneof the cells here protect the skin from abrasion and penetration. protects deep cells from external environment.
papillary layer
layer of dermis made of areolar connective tissue. connective tissue with defensive cells like phagocytes. has dermal papillae that indent the overlying epidermis. papillae cause skin ridges called friction ridges that enhance gripping ability in hands and feet and also contribute to our sense of touch. layer of the skin that contains the blood vessels and nerves that are closest to the surface of the skin
reticular layer
deeper layer of dermis. accounts for 80% of the thickness of the dermis and tension lines in skin. irregular dense fibrous connective tissue (strong). extracellular matrix includes adipose cells and thick bundles of collagen fibers. separations betweenthese bundles form cleavage lines (externally invisible and run longitudinally).
flexure lines
skin markings caused by dermal folds that occur at or near joints where the dermis is tightly secured. this skin cannot slide easily to accommodate joint movement so creases form
melanin
pigment that contributes to skin color. synthesized from melanocytes. this protects the DNA of skin cells from UV radiation by absorbing the sun rays (natural sunscreen). differences in skin color depend on the kind and amount of this made. produced in the skin
carotene
pigment that contributes to skin color. yellow/orange pigmant found in plants (carrots). accumulates in stratum corneum and can cause skin color change when eaten a lot. this can also be converted to vitamin A, which is essential for vision.
hemoglobin
pigment that contributes to skin color. oxygenated pigment in RBC’s that causes a pinkish hue of fair skin. white people have little melanin so this color shows through the skin easily
skin
made up for epidermis (superficial region), dermis (middle region) and hypodermis (deepest region and technically not a part of skin).
hair
flexible strands of dead keratinized cells. contains hard keratin. major regions include medulla(only part with soft keratin), cortex and outermost cuticle. pigment is melanin. functions include alerting the body to presence of incets on the skin and guarding the scalp against physical trauma, heat loss and sunlight
hair follicle
extends from epidermis into dermis to form hair. includes hair bulb (expanded deep end), outermost sheath is connective tissue sheath. has a hair follicle receptor (root hair plexus) that is a sensory nerve ending around each hair bulb and it stimulated by bending hair (acts as touch receptrs). attached to arrector pili
arrectior pili
smooth muscle in dermis attached to hair follicles. when it contracts it pulls the hair follicle upright and dimples the skin to produce goose bumps. most important role is to force sebum out of the hair follicle to the skin surface
vellus hair
type of hair. body hair of children and adult females. pale, fine
terminal hair
type of hair. coarse, long hair of eyebrows, scalp, axillary and pubic regions (and face and neck of males)
hair growth
growth phase (weeks to years) is followed by regressive stage and resting phase (1-3 months). growth phase varies (6-10 years in scalp and 3-4 years in eyebrows). influenced by nutrition and hormones
alopecia
hair thinning in both sexes after age 40. process begins at the anterior of hairline and progresses posteriorly. caused by cell division in the hair matix slowing down
true (frank) baldness
male pattern baldness is a type of this. genetically determined and sex-influenced. caused by response of hair follicles to DHT (a metabolite of testosterone)
nail
scalelike modification of the epidermis. keratinized and translucent. parts include the matrix, lunula, eponychium and hyponychium. appears pink because of capillaries in the underlying dermis
sweat glands
sudoriferous glands. 2 types: eccrine and apocrine.
eccrine (merocine) sweat glands
abundant on palms, soles and forehead but found on almost all surfaces. secrets in dermis into a duct that connects to pores. help thermoregulation and cools body. sweat is 99% water with NaCl, vitamin C,antibodies, metabolic wastes, and dermicidin(kills bacteria). sweat is acidic.
apocrine sweat glands
confined to axillary and anogenital areas. composed of sweat plus fatty substances and proteins. located deep in dermis and ducts empty onto hair follicles. become active at puberty. contain human phermones. activated during pain and stress. secrete into hair follicle. have secretions that are enriched with fats and proteins.
ceruminous glands
specialized apocrine glands. in ear canal. secretes water that mixes with sebum to make cerumen (earwax)
sebaceous glands
oil glands. found in dermis next to hair follicle. form sebum. secretion of sebum is stimulated by hormones. by all over body. becomes active at puberty. discharge an oily secretion into hair follicles.
Acne involves inflammation of sebaceous glands.
Sebum functions to lubricate the hair and skin.
Most sebaceous glands open into hair follicles.
Sebum can function as an antibiotic.
sebum
oily holocrin secretion. softens/lubricates hair and skin. slows water loss. bactericidal (kills bacteria). it is a semisolid, composed mostly of lipids. barrier against microbes and is a pheromone.
basal cell carcinoma
least malignant and most common (80%) type of cancers. stratum cells proliferate, invading the dermis and hypodermis. cured by surgical excision in 99% of cases.
squamous cell carcinoma
2nd most common skin cancer. arises from keratinocytes of stratum spinosum. most common on scalp, ears, lower lip and hands. good prognosis if caught early and removed surgically or by radiation therapy. skin cancer appears as a scaly reddened papule and tends to grow rapidly and metastasize
melanoma
cancer of melanocytes. it is the most dangerous skin cancer because it is highly metastic (spreads) and is resistant to chemotherapy. accounts for 2-3% of skin cancer. treated by wide surgical excision accompanied by immunotherapy
burns
tissue damage by heat, electricity, radiation, chemicals. leads to denatured protein, cell death. causes dehydration and electrolyte imbalance which leads to renal shutdown and circulatory shock
first degree burn
only epidermis is damaged. localized redness, swelling (edema) and pain. usually heal in 2-3 days without special attention. like a sunburn
second degree burn
epidermis and upper dermis damage. blisters appear. skin regeneration in 3-4 weeks with little or no scarring if taken care of to preven infection.
third degree burn
full thickness burn. entire thickness of skin is damaged. burn area is gray/whitem cherry or black. no edema (swelling) or pain (nerve endings destroyed). skin grafting is usually necessary (transplant of skin)
cyaonsis
bluish or grayish discoloration of the skin and mucous membranes that occurs with reduced oxygen levels
anemia
when a person does not have enough healthy RBCs. so they appear more pale
pacinian corpuscle or lamellar corpuscle
type of cutaneous (skin) sensory receptors. They are nerve endings in the skin responsible for sensitivity to vibration and pressure.
lamellar granules
in stratum granulosum of epidermis. contains water resistance glycolipid that protects us from water loss through the skin
tight junctions
help prevent molecules from passing through the extracellular matrix between cells
desmosomes
type of anchoring junction. abundant in tissues that are subject to great stress
gap junctions
communicating junction. present in electrically excitable tissues
hirsutism
excessive hairiness. results from adrenal gland or ovarian tumor that secrets large amounts of androgens
hair matrix
produces hair
metabolic function of skin
when sun hits skin, modified cholesterol are converted to vitamin D precursor which is transported to other body areas to be converted to vitamin D
blisters
caused by fluid accumulation coming from the plasma of the blood flowing through the numerous dermal blood vessels
Vernix caseosa
whitish material produced by fetal sebaceous glands. on a new born baby
Porphyria
an inherited condition that affects the heme pathway; it leaves the skin scarred and gums degenerated, and may have led to the folklore about vampires.
body’s first line of defense against disease
intact skin and mucous membranes (external). include tears, mucus membranes, and the skin.
chemotaxis
The directional movement of cells in response to chemicals. process whereby neutrophils and other white blood cells are attracted to an inflammatory site
inflammatory response
sets the stage for repair processes, prevents the spread of the injurious agent to nearby tissue, disposes of cellular debris and pathogens
NK (natural killer) cells
NK cells attack cells that display abnormal MHC antigens. NK cells attack cancer cells and virus-infected body cells. NK cells are present in the blood, spleen, lymph nodes, and red bone marrow. induce the target cell to undergo “apoptosis” (cell suicide). NK cells attack transplanted organs.
phagocytosis
event: chemotaxis, adherence, ingestion, digestion, killing
interferons
produced by virus-infected cells. It is released to neighboring cells to warn them of the presence of the virus and to aid them in producing defenses against the viruses. interfere with viral replication within cells and protects cells that have not yet been infected by viruses. they activate macrophages
opsonization
Complement proteins and antibodies coat a microorganism and provide binding sites, enabling macrophages and neutrophils to phagocytize the organism. an effect of complement activation
Phagocyte mobilization
involves mainly neutrophil and macrophage migration into inflamed areas. steps include leukocytosis (neutrophils enter blood from bone marrow), margination, diapedesis (neutrophils flatten and squeeze between the endothelial cells of the capillary walls) and chemotaxis (neutrophils/WBC migrate up the gradient to the site of injury)
Fever
is regulated by chemicals called pyrogens that reset the body’s thermostat to a higher setting. it is an adaptive response that seems to benefit the body
hyperemia
redness and heat of an inflamed area caused congestion of blood (vasodilation)
inflammation
results in redness, heat (increased blood flow to region), pain, and swelling (blood plasma leakage)
innate immune defenses
inflamation, NK cells, fever, phagocytes, antimicrobial proteins
antigens
Substances capable of triggering the adaptive immune system and provoking an immune response. includes reactivity with an antibody. one may have many different antigenic determinants and may therefore cause the formation of more than one antibody. mobilizes the adaptive defenses and provokes an immune response
haptens
Small molecules that bind with self-proteins to produce antigenic substances
adaptive immune system
It has memory.
It is systemic.
It is antigen-specific.
immunocompetence
cells must become able (competent) to recognize its one specific antigen by binding to it
antibodies
Soluble proteins secreted by plasma B cells. composed of heavy and light polypeptide chains. polypeptides linked together by disulfide bonds. provide protection by complement fixation. they can binding and inactivating chemical toxins released by bacteria or other microorganisms. linking soluble antigens together so that they fall out of solution. targeting foreign cells so that complement proteins can cause cellular lysis. used to diagnose pregnancy, hepatitis and rabies
Cytotoxic T cells
lymphocytes that directly kill virus- infected cells. attack cancer cells.
Recognition of infected host cell using its TCR
Recognition of infected host cell using its CD8 glycoprotein
Secretion of perforin
Secretion of granzyme
isografts
organ transplants between identical twins.
helper T cells
function in the adaptive immune system activation. most critical cell in immunity. required for adaptive immune response. coordinate cellular and humoral immune responses. releases chemicals that stimulate macrophages. activate B cells and cytotoxic T lymphocytes to kill infected host cells.
regulatory T cells
function in preventing autoimmune reactions
cytokines
mobilize immune cells and attract other leukocytes into the area. released by T cells and macrophages
insensible perspiration
Water loss due to evaporation of fluid that has penetrated through the skin. routine and unnoticeable sweating. about 0.5 liter per day
epidermal ridges
interconnect with the dermal papillae. cause ridge patterns on the surface of the skin.extend into the dermis.
produce patterns that are determined genetically.
lanugo
very fine, soft hair as can be found on the body of a fetus or newborn baby
hair papilla
supplies nutrients and blood to growing hair
Meissner’s corpuscles or tactile corpuscles
a type of nerve ending in the skin that is responsible for sensitivity to light touch.
greater omentum
a large fold of visceral peritoneum that hangs down from the stomach.
lesser omentum
the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach
mesentery
a fold of membranous tissue that arises from the posterior wall of the peritoneal cavity and attaches to the intestinal tract.
mesojejunum
mesentery of the jejunum (the second part of the small intestine)
mesometrium
mesentery of the uterus
mesoappendix
mesentery of the appendix
falciform ligament
ligament that attaches the liver to the anterior (ventral) body wall.
ligament teres or round ligament
string of tissues and fibers around uterus. along the inferior edge of the falciform ligament
mesosalpinx
part of the lining of the abdominal cavity in higher vertebrates, specifically the portion of the broad ligament that stretches from the ovary to the level of the uterine tube.
mesovarium
the portion of the broad ligament of the uterus that suspends the ovaries.
broad ligament
wide fold of peritoneum that connects the sides of the uterus to the walls and floor of the pelvis.
dermal pillae
projections of the dermis that form indentations in the overlying epidermis
dermal ridges
cause the overlying epidermis to form epidermal ridges. Collectively these ridges are called friction ridges (fingerprints)
root hair plexus or hair follicle receptor
wrap around each hair bulb. when the hair bends, these are stimulated. these cause our hair to act as sensitive touch receptors
porphyria
inherited condition that affects the heme pathway; it leaves the skin scarred and gums degenerated, and may have led to the folklore about vampires.
innate internal defenses
Phagocytotic cells such as macrophages identify a variety of enemies by recognizing markers unique to pathogens.
antigen determinant
unique area (specific region) that a lymphocyte recognizes and binds to
humoral immunity
type of immunity that can be transferred by bodily fluids from one person to another, thus conferring immunity to the recipient
cell-mediated immunity (cellular immunity)
activated if a virus attacks a cell. involves an intracellular pathogen such as a virus
intracellular pathogens that reside within host cells, foreign tissue transplants, and some cancer cells respond to this
innate defense system
inflammatory response and skin and mucous membranes
adaptive defense system
immune response. include both humoral and cellular immunity.
activated complement
insertion of MAC and cell lysis
opsonization
enhancement of inflammation
alternative pathway
classical pathway
lectin pathway
leukocytosis
When neutrophils enter the blood from the red bone marrow, in response to leukocytosis-inducing factors
