Anatomy of the integumentary system study guide Flashcards
What tissues and organs are part of the integumentary system?
- skin
- hair
- nails
- sweat glands
- sebaceous (oil) glands
What are the 2 distinct regions of skin? What type of tissue is in each region?
- epidermis: epithelial tissue
- dermis: fibrous connective tissue
Define hypodermis. What are its components and function?
superficial fascia
- not part of the skin
- subcutaneous layer deep to the skin
- mostly adipose tissue; absorbs shock and insulates
- anchors skin to underlying structures
Memorize the 5 layers of the epidermis! Know where the epidermis has 5 layers vs 4 layers.
- thick skin has 5 (CLGSB)
- thin skin as four (CGSB)
What are the 4 cell types in the epidermis?
- keratinocytes: produce keratin, connected by desmosomes, we lose millions daily
- melanocytes: produce melanin pigment, located in deepest epidermis
- dendritic (langerhans) cells: key activators of immune system
- tactile (merkel) cells: sesnroy receptors that sense touch
Review the specifics on each of the 5 epidermal layers – slides 6 to 10.
- basal: bottom layer, attached to dermis, divides to produce daughter cells that migrate to the surface over days, 10-25% is made up of melanocytes
- stratum spinosum: pickly layer, several layers, thick, contains thick bundles of pre keratin filaments attached to desmosomes
- granulosum: cells flatten, cells above this layer die (too far from dermal capillaries, nuclei and organelles disintegrate, keratinization begins
- stratum lucidum: only thick skin, consists of think translucent band; 2-3 rows of clear flat dead keratinocytes
- corneum: 20-30 rows of flat a-nucleatued dead keratinized cells, thickest layer, protection for the deeper layers
What does the dermis contain? What are the two layers of dermis?
- nerves, blood vessels, lymphatic vessels, epidermal hair follicles, oil glands, sweat glands
- papillary and reticular layers
What type of connective tissue is found in the papillary layer? In the reticular layer?
papillary: areolar connective tissue
reticular: course, dense, fibrous connective tissue
What are dermal papillae?
superficial region of dermis-contains finger like projections to the epidermis
- projections contain capillary loops, free nerve endings, and touch receptors (meissner’s corpuscles)
Be familiar with the concepts of cleavage lines and flexure lines.
cleavage lines: caused by many collagen fibers running parallel to the skin surface (invisible but helpful for surgeons to avoid scarring)
flexure lines: dermal folds at/near joints (where dermis is connected to deeper structures, prevents skin from sliding around, seen in hands and toes)
Know the function of Meissner’s/Tactile Corpuscles vs Pacinian/Lamellar Corpuscles.
meissners/tactile corpuscles = sense light touch
pacinian/lamellar corpuscles = sense deep pressue
Where is the cutaneous plexus? What is it?
in the reticular layer
- network of blood vessels between reticular layer and hypodermis
What 3 pigments combine to create skin color?
melanin, carotene, hemoglobin
What causes blisters? Stretch marks?
stretch marks: dermal tears
blisters: acute, short term traumas to skin. they are fluid filled pockets between epidermal and dermal layers
How does excessive sun exposure damage skin? Lead to skin cancer?
- elastic fibers clump, skin becomes leathery
- alteration in DNA and depression of the immune system can lead to skin cancer
What abnormal skin color(s) could you note with the following medical conditions: cyanosis, pallor, erythema, jaundice, bruises.
- cyanosis: blueish skin color
- jaundice: yellow
- erythema: red
- pallor: pale
- bruises: black/blue
What’s the difference between the hair root and the hair shaft?
shaft: area that extends above the scalp, keratinization is complete
root: area within the scalp, keratinization is ongoing
What makes up hair? What functions does hair perform?
- consists of dead or keratinized cells
functions: - warn insects off skin
- guard against physical trauma
- protect from heat loss
- shield skin from sunlight
What pigment determines hair color?
melanin/melanocytes
What are the free edge, nail plate, eponychium, and hyponychium of a nail?
free edge: nail tip that grows off finger
nail plate: big flat part of nail
eponychium: cuticle, skin fold that project onto surface of nail body
hyponichium: area under the free edge of the nail plate
What can cause nail clubbing?
low levels of oxygen/respiratory diseases
What is contained in sweat?
water (mostly), some salts, vitamin c, antibodies, dermcidin (microbe-killing peptide), metabolic waste
What’s the anatomical difference between eccrine and apocrine sweat glands?
Eccrine (merocrine):,not connected to hair follicle, smaller (palms, soles of feet, forehead)
apocrine: bigger, connected to hair follicle (axillary and anogenital areas)
Where would you find eccrine vs apocrine sweat glands?
eccrine: palms, feet, forehead
aporcine: axillary, anogenital
