Integumentary system/skin
-Comprised of skin, hair nails and sweat glands -Protection and barrier -Thermoregulation -Involved in vitamin D synthesis -Cutaneous (skin) sensations -Minor role in excretion and absorption
What is the largest organ in the body?
Skin (integumentary system)
Epithelial
outer layer
connective
underlies dermis
smooth muscle
goose bumps
nervous
sensory receptors
Epidermis
The outer layer of skin, composed of epithelium and underlying connective tissue dermis
subcutaneous tissue or hypodermis
Fatty tissue found beneath the dermis
keratinocytes (keratin cells)
these epithelial cells produce keratin a tough fibrous protein that gives the epidermis its durability and protective capabilities
Stratum Basale (basal layer)
single row of cells that abuts the dermis, its cells constantly undergo cell division to produce millions of new cells daily
stratum spinosum (spiny layer)
immediately superficial to the basal layer, its cells appear spiky, cells in the basal and spiny layer are the only ones that receive adequate nourishment (diffusion from the dermis)
stratum granulosum (granular layer)
contains cells that are like granules, some of these granules contain a waterproofing glycolipid that is secreted into the extracellular space
Stratum lucidum (clear layer)
thin translucent band of flattened dead keratinocytes, it is not present in the skin
Stratum corneum (horny layer)
most superficial layer; dead cells filled with keratin (barrier area)
papillary layer
very uneven and has fingerlike projections from its superior surface called dermal papillae which attack it to the epidermis above
reticular layer
The deeper layer of the dermis that supplies the skin with oxygen and nutrients, contains blood vessels, sweat and sebaceous glands, and pressure receptors
arrestor pili
small band of smooth muscle attached to follicle. Responsible for "goose bumps"
Nail Folds (Finger Nail)
Skin flap overlapping nail`s borders
nail matrix
the part of the nail beneath the body and root from which the nail is produced
Function of skin
protection, prevents penetration, perception, temperature regulation, identification, communication, wound repair, absorption and excretion, production of vitamin D
granulosum
layer containing sacs filled with fatty material of keratin subunits
corneum
dead cells
papillary
the more superficial dermis layer
epidermis
avascular region
dermis
major skin area where derivatives (nails and hair) reside
spinosum
epidermal region exhibiting the most mitoses
corneum
most superficial epidermal layer
reticular
has abundant elastic collagenic fibers
basale
region where melanocytes are most like to be found
Corneum
accounts for most of the epidermis
Vitamin D
substance that is manufactured in the skin (but is not a secretion) to play a role elsewhere in the body
sebaceous glands
acne is an infection of an
hair follicle
structure that houses a hair
eccrine sweat glands
more numerous variety of perspiration gland that produces a secretion containing water, salts, and vitamin c; activate6d by rise in temperature
hair
sheath formed of both epithelial and connective tissues
apocrine sweat glands
type of perspiration production gland that produces a secretion containing proteins and fats in addition to water and salts
hair
found everywhere on body except palms of hands and soles of feet
arrector pili
specialized structures that respond to environmental stimuli
hair
primarily dead/keratinized cells
Sabaceous glands
Its secretion contains cell fragments
nail
"sports" a lunula (moon) and cuticle
Function skin
protection temperature regulation sensation storage of chemical compounds excretion of waste synthesis of compounds determines characteristics
Epidermis
avascular (no blood vessels)
Dermis
highly vascular (has blood vessels)
Epidermis
receives nourishment from dermis
function of hair
protection thermoregulation sensory minor role in human
Hair
has connective and epithelial tissue
Alleles
two forms of a gene (dominant & recessive)
Genotype
gene combination for a trait
phenotype
An organism's physical appearance, or visible traits.
Homozygous genotype
gene combination involving 2 dominant or 2 recessive genes (ex: RR or rr); also called pure
Heterxygous genotype
gene combination of one dominant and one recessive allele (Rr) also called hybrid
Inheritable factors or genes
Responsible for all heritable characteristics
Law of Dominance
In a cross of parents that are pure for contrasting trais only one form of the trait will appear in the next generation RR x rr yields all Rr
Law of Segregation
Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
law of independent assortment
the law that states that genes separate independently of one another in meiosis
gamete
sex cell
epidermis
the outer layer of skin
dermis
the inner layer of skin
subcutaneous tissue
the masses of connective tissue beneath the inner layer of skin
basal cells
cells of the skin that reproduce
melanin
pigment that helps protect the deeper layer of epidermis
Melanin
produced in melanocytes—the cells, which at normal conditions are localized in the basal layer of the epidermis
melanoma
an irregularly shaped blue-black colored growth on the skin, especially on areas exposed intermittently to high-intensity sunlight
contact dermatitis
an itchy rash caused by direct contact with a substance or an allergic reaction to it
disorder vs disease
Disease: A particular distinctive process in the body with a specific cause and characteristic symptoms. Disorder: Irregularity, disturbance, or interruption of normal functions.
dermis
blood vessels supplying the skin are located in
layer of insulation
the subcutaneous layer functions as a
Sebaceous glands
the glands associated with hair follicles are
keratinization
Nails are produced by epidermal cells that undergo
eccrine glands
sweat glands associated with regulation of body
Sebaceous glands
sweat glands associated with acne
Studied by 38 People