UNIT 2 - INTEGUMENTARY SYSTEM Flashcards
- ________: bluish-purple hue
- ________: yellow discoloration
- ________: redness of the skin caused by hyperemia (increased blood flow)
- ________: pale color of the skin
- cyanotic
- jaundice
- erythema
- pallor
skin is:
- _____ sq. meter
- _____ kg
- _____ %
- 2 sq meter
- 4.5-5 kg
- 7%
3 accessory structures
hair
nails
glands
layers of the skin
epidermis
dermis
hypodermis
epidermis under the microscope
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
- dermis
- dead keratinocytes
- lamellar granules
- keratinocyte
- langerhans cell
- melanocyte
- merkel cell
- tactile disc
- sensory neuron
- 25 to 30 layers of flattened dead keratinocytes
- Continuously shed and replaced by cells from the deeper strata
- Contains mostly keratin
- Help to protect deeper later from injury and microbial invasion
- ________
- Abnormal thickening of the ___________
- Due to constant exposure of skin to friction
- stratum corneum (horn/horny)
- Callus
- stratum corneum
Present only in the thick skin areas:
* Fingertips
* Palms
* Soles
- Consists of three to five layers of flattened clear, dead keratinocytes that contain large amounts of keratin and thickened plasma membranes
- stratum lucidum
- Middle of the epidermis
- Consists of three to five rows of flattened keratinocytes that are undergoing apoptosis.
- Programmed cell death
- Organelles are beginning to degenerate
Contains keratohyalin
* Darkly staining granules of a protein
* Converts the tonofilaments into keratin
Contains lamellar granules
* Release lipid-rich secretion
* Acts as a water-repellant sealant
- Marks the transition between the deeper, metabolically active strata and the dead cells of the more superficial strata
- stratum granulosum
- Superficial to the stratum Basale
- Eight to ten layers of many-sided keratinocytes with bundles of tonofilaments
- Thornlike spines
- Langerhans cells and projections of melanocytes are also present in this layer
- stratum spinosum
§ Aka Stratum germinativum to indicate its role in forming new cells
§ Deepest later of the epidermis
§ Composed of single row of cuboidal or columnar keratinocytes.
§ Some cells are stem cells
§ Contents of the keratinocytes of stratum Basale
* Nuclei are large
* Cytoplasm contains many ribosomes
* A small Golgi complexes
* Few mitochondria
* Some rough endoplasmic reticulum
* Cytoskeleton includes intermediate filaments
— ___________
a. Composed of protein that will from keratin in more superficial epidermal layers
b. Melanocytes and Merkel cells with their associated Merkel discs are scattered among the keratinocytes of the basal layer.
- stratum basale
- Tonofilaments
stages of hair growth
- anagen - growth
- catagen - regression
- telogen - resting
- cells of the hair matrix divide
anagen (growth)
- Following the growth stage
- when the cells of the hair matrix stop dividing, the hair follicle atrophies (shrinks), and the hair stops growing
catagen (regression)
- After the regression stage, the hair follicle enters this stage
telogen (resting)
types of hair
- lanugo
- terminal hair
- vellus hair
- Usually by the fifth month of development, the follicles produce very fine, nonpigmented, downy hairs that cover the body of the fetus
lanugo
Prior to birth, the lanugo of the eyebrows, eyelashes, and scalp are shed and replaced by long, coarse, heavily pigmented hairs
- In response to hormones (androgens) secreted at puberty, this replace vellus hairs in the axillae (armpits) and pubic regions of boys and girls
terminal hairs
- lanugo of the rest of the body are replaced by this
- commonly called “peach fuzz”
- short, fine, pale hairs that are barely visible to the naked eye
- During childhood, this covers most of the body except for the hairs of the eyebrows, eyelashes, and scalp, which are terminal hairs
vellus hairs
- _______: oil gland
- _______: sweat gland
- _______: modified sweat glands in the external ear, produce a waxy lubricating secretion
- sebaceous gland
- sudoriferous gland
- ceruminous gland
- opens into epidermis
- throughout the skin (EXCEPT:lip margin, nail bed, penis, clitoris, labia minora and eardrums)
- perspiration
- soon after birth
- emotional stress
- thermoregulation
eccrine
- opens into hair follicle
- Axilla, groin, areola, beard region, clitoris, labia minora
- perspiration + lipids and CHON
- puberty
- emotional stress and sexual excitement
- X thermoregulation
apocrine
functions of the skin
- thermoregulation
- blood reservoir
- protection
- keratin
- lamellar granules
- langerhans cells
- macrophages
- melanin
- sebum
- acidic ph - cutaneous sensation
- tactile
- thermal
- pain - excretion and absorption
- vitamin d synthesis
- high envi temp: lower body temp
– sweating –> dilation of blood vessels –> - lower envi temp: high body temp
– constriction of BV –> production of sweat decreased
THERMOREGULATION
- carry 8–10% of the total blood flow
BLOOD RESERVOIR