integumentary

Question 1

skin functions

Answer 1

• first line of defense against infection
• protect underlying tissues
• receives stimuli for touch, pressure, pain, + temperature for nervous system
• regulates body temp
• excretes salts, water, organic wastes
• protects from excessive water loss
• synthesizes vitamin D3 (converts calcitriol for normal calcium metabolism)
• stores nutrients

Question 2

skin layers

Answer 2

1. epidermis
2. dermis
3. hypodermis (subcautaneous fat)

Question 3

epidermal appendages

Answer 3

1. nails
2. hair
3. glands (sebaceous + sweat)

Question 4

normal bacterial flora

Answer 4

• gram-positive + gram-negative staphylococci
• pseudominas
• streptococcus

pH of 4.3-5.6 halts bacteria growth

Question 5

3 phases

wound healing phases

Answer 5

1. inflammatory: begins at time of injury, lasts 3-5 days (local edema, pain, redness, itchiness, warmth, possible exudate)
2. fibroblastic: 4th day to 2-4 weeks (scar tissue + granulation tissue forms)
3. maturation: 3 weeks after injury for up to a year (scar tissue is thin, firm, inelastic)

Question 6

1st to 3rd intention

healing by attention

Answer 6

1st intention: approximate wound edges are held in place (sutures) until healing occurs, wound easily closes

2nd intention: injuries or wounds with tissue loss + gradual filling of dead space with connective tissue loss

3rd intention: delayed primary closues, occurs with wounds that are left open for irrigation or debris removal

Question 7

diagnostic tests

Answer 7

• skin biopsy
• skin/wound cultures
• Wood’s light (UV test) - for superficial skin infections
• diascopy - for lesion inspection

Question 8

what it is + signs

candida albicans

aka yeast infection or thrush

Answer 8

superficial fungal infection of the skin + muscous membranes

risk factors: immunosuppression, long-term antibiotic therapy, medications, diabetes mellitus, obesity

signs
- skin: red/irritated, itches, stings
- mouth: red + whiteish patches

Question 9

shingles

aka herpes zoster

Answer 9

caused by reactivation of the varicella-zoster virus with history of chicken pox

• dormant virus is in dorsal nerve root ganglia of sensory cranial + spinal nerves
• may have postherpetic neuralgia when lesions resolve
• contagious to individuals who never had chicken pox + are not vaccinated

signs:
- unilaterally clustered vesicles
- fever, malaise
- burning + pain
- paresthesia
- pruritis

Question 10

methicillin-resistant staphylococcus aureus

Answer 10

• skin/wound becomes infected with MRSA
• community acquired (skin-to-skin contact, equipment sharing) or hospital acquired
• can present as folliculitis (follicule infection from staphylococcus), raised red rash + pustules
• or furuncles (deep in follicle)
• if MRSA infects the blood sepsis, organ damage, + death can occur
• contagious (spread by direct skin contact)

Question 11

erysipelas + cellulitis

Answer 11

• erysipelas: acute/superficial infection affecting upper layers of skin from group A streptococcus from wound
• cellulitis: infection of dermis + hypodermis from streptococcus or staphylococcus aureus
• signs: pain, erythema, warmth, edema, fever

Question 12

skin cancer types

Answer 12

basal cell: from epidermis, metastasis rare
squamous cell: tumor of epidermal keratinocytes, can infultrate surrounding structures + metastasize to lymph nodes
melanoma: mostly appear where birthmarks or new moles are apparent, highly metastatic to the brain, lungs, bone, + liver

signs: change in color/size/shape of preexisting lesion, pruritus, local soreness

Question 13

psoriasis

Answer 13

chronic, non-infetious skin inflammations involving keratin synthesis

Question 14

stevens-johnson syndrome

Answer 14

medication-induced reaction (antibiotics, antiseizure meds, NSAIDS)

diffuse erythema + blister formation on skin + muscous membranes, severe reactions involve respiratory system, renal system, eyes, can be fatal

more common in patients with impaired immune systems

Question 14

what it is + meds

dermatitis

Answer 14

superficial inflammatory process involving the epidermis

meds:
* topical immunosuppressants (tacrolimus + pimecrolimus creams) - side effects include redness, burning, itching, sunlight sensitvity
* systemic immunosuppressants (methotrexate, oral glucocorticoids)

Question 15

purpose

topical glucocorticoids

Answer 15

• antiinflammatory, antipruritic, + vasoconstrictive actions

side effects: burning, dysness, irritation, itching, thining of skin, skin atrophy, acneiform eruptions, hypopigmentation, bacteria/fungi/virus overgrowth

Question 17

actinic keratosis

Answer 17

from prolonged exposure to the sun - rough, scaly, red/brown lesions

meds:
- diclofenac sodium (nonsteroidal antiinflammatory)
- fluorouracil (affects DNA + RNA synthesis, results in healing)
- imiquimod 5% cream
- ingenol mebutate

Question 18

psoriasis

Answer 18

chronic inflammatory disorder

meds: glucocorticoids, tazarotene (vit A derivative)

Question 19

burn medications

Answer 19

• silver sulfadiazine: broad spectrum of activity against gram-negatice bacteria, gram-positive bateria, + yeast (decreases microbial colonization, does not improce wound healing), prevents sepsis with burns
• mafenide acetate: bacteriostatic for gram-negative + gram positive organisms, reduces bacteria present in avascular burn prodicts