Integumentary System Flashcards
What depends on the underlying vascularized dermis for nutrition?
Epidermis
What is a dense layer of interconnecting collagen and elastic fibers containing sebaceous glands, sweat glands, hair follicles, and most of the terminals of the cutaneous nerves?
Dermis
What inferiorly merges with subcutaneous fatty tissue, or adipose tissue?
Dermis
Normal skin color depends on the amount and type of what?
Melanin
Normal skin color is also influenced by underlying vascular structures, changing hemodynamics, and changes in what?
Carotene and bilirubin
What is genetically determined and increased by exposure to sunlight?
Amount of melanin, a brownish pigment
What is found in the subcutaneous fat and heavily keratinized areas such as the palms and soles?
Carotene, a yellow pigment
What arises from the breakdown of heme in the red blood cells?
Bilirubin, a yellow-brown pigment
What transports oxygen in the form of
oxyhemoglobin, a bright red pigment in the arteries and capillaries
that causes reddening of the skin?
Hb
After passing through the capillary bed and releasing oxygen to the tissues, the darker bluer pigment of what circulates in the veins?
Deoxyhemoglobin
What makes the veins look bluer and less red than circulating venous blood?
The scattering of light through the turbid superficial layers of the skin
or blood vessels
Adults have two types of hair:
- Vellus hair
2. Terminal hair
What is is short, fine, inconspicuous, and relatively
unpigmented?
Vellus hair
What is coarser, thicker, more conspicuous, and
usually pigmented?
Terminal hair
What can protect the distal ends of the fingers and toes?
Nails
What is the whitish moon?
Lunula
Roughly one-fourth of the nail plate, the nail root, is covered by what?
Proximal nail fold
What extends from the fold and, functioning as a seal, protects
the space between the fold and the plate from external moisture?
Cuticle
What cover the sides of the nail plate?
Lateral nail folds
The angle between the proximal nail fold and nail plate is normally what?
Less than 180°
Fingernails grow approximately how many mm daily?
0.1 mm
What produce a fatty substance secreted onto the skin surface through the hair follicles?
Sebaceous glands
What glands are present on all skin
surfaces except the palms and soles?
Sebaceous glands
Sweat glands are of two types:
eccrine and apocrine
What are widely distributed, open directly onto the skin surface, and by their sweat production help to control body temperature?
Eccrine glands
What are found chiefly in the axillary and genital regions and usually open into hair follicles?
Apocrine glands
What is responsible for adult body odor?
Bacterial decomposition of apocrine sweat
COMMON OR CONCERNING SYMPTOMS:
- Growths
- Rashes
- Hair loss or nail changes
If the patient reports a new growth, it is important to what?
- Pursue the patient’s personal and family history of skin cancer
- Note the type, location, and date of any past skin cancer and ask about regular self-skin examination
- Use of sunscreen
For itchy rashes, ask about seasonal allergies with itching and watery eyes, asthma, and atopic dermatitis, often accompanied by
Rash on the inside of the elbows and knees in childhood
Causes of generalized itching, without apparent rash, include:
- Dry skin
- Pregnancy
- Uremia
- Jaundice
- Lymphomas and leukemia
- Drug reactions
- Less commonly, polycythemia vera and thyroid disease
Common nail changes:
Onychomycosis, habit tic deformity, and melanonychia
What is a fungal infection of the nails that causes discoloration, thickening, and separation from the nail bed?
Onychomycosis
What is a form of nail degeneration that results from constant external trauma to the nail matrix (where the fingernails start to grow, the root) that manifests as nail plate (top of the nail) changes?
Habit tic deformity
What is characterized by brown-black discoloration of the nail plate and the pigment referred to is conventionally melanin?
Melanonychia
The most common causes of diffuse hair thinning are what?
Male and
female pattern baldness
What s common in telogen effluvium and
alopecia areata?
Hair shedding at the roots
What suggest damage from hair care or tinea
capitis?
Hair breaks along the shaft
What are caused by a combination of genetic predisposition and
ultraviolet radiation exposure?
Skin cancer
Who has the highest risk of skin cancer?
Fair-skinned individuals
What is the most common skin cancer?
Basal cell carcinoma (BCC), followed
by squamous cell carcinoma (SCC), and melanoma
What is the least common skin cancer?
Melanoma
What is the most lethal due to its high rate of metastasis and high mortality at advanced stages, causing over 70% of skin cancer deaths?
Melanoma
Increasing lifetime sun exposure correlates directly with
Increasing risk of skin cancer
What appears to be more harmful than chronic
exposure?
Intermittent sun exposure
What is the best defense against skin cancers?
- avoid ultraviolet radiation exposure by limiting time in the sun - avoiding midday sun - using sunscreen - wearing sun-protective clothing with long sleeves and hats with wide brims
Use of these especially before age 35 years, increases
risk of melanoma by as much as 75%.
Indoor tanning beds
Signs of chronic sun damage include what?
- numerous solar lentigines on the shoulders and upper back - many melanocytic nevi - solar elastosis (yellow, thickened skin with bumps, wrinkles, or furrowing) - cutis rhomboidalis nuchae (leathery thickened skin on the posterior neck) - actinic purpura
Who recommends full body
examinations for patients over age 50 years or at high risk,
because melanoma can appear in any location?
American Cancer Society (ACS) and the AAD
High-risk patients of skin cancer are those
With a personal or family history of
multiple or dysplastic nevi or previous melanoma
Patients who have a clinical skin examination within the 3 years prior
to a melanoma diagnosis have
Thinner melanomas than those who
did not have a clinical skin examination
Both new and changing nevi should be closely examined, as at least
half of melanomas arise de novo from
Isolated melanocytes rather than pre-existing nevi
Screening for Melanoma
The ABCDEs
What is done in screening moles for melanoma (this does not apply for non-melanocytic lesions like seborrheic keratoses)?
ABCE-EFG method
The sensitivity of this tool for detecting melanoma ranges from
43% to 97%
The specificity of this tool for detecting melanoma ranges from
36% to 100%
What depends on how many criteria are used to define
abnormality?
Diagnostic
accuracy
If two or more of these features are present, what should be
considered?
Biopsy
The most sensitive is E, which stands for what?
Evolution or change
What used for many years to teach clinicians
and patients about features suspicious for melanoma, to help detect
aggressive nodular melanomas?
ABCDE method
Instruct patients with risk factors for skin cancer and melanoma,
especially those with what
a history of high sun exposure, prior or family
history of melanoma, and ≥50 moles or >5 to 10 atypical moles, to
perform regular self-skin examinations
What is an increasingly useful office practice for deciding
whether a melanocytic lesion is benign or malignant?
Dermoscopy
This handheld device provides cross-polarized or unpolarized light to
visualize patterns of pigmentation or vascular structures
Dermoscope
It is important for you to palpate lesions for what?
- Texture
- Firmness
- Scaliness
Because frequent handwashing increases the risk of irritant contact
dermatitis, dermatologists recommend using what?
Hand sanitizers, which
are less drying than soap and water
Good descriptions include each of the following elements:
number,
size, color, shape, texture, primary lesion, location, and
configuration
For example, for seborrheic keratosis, examine and record:
Multiple
5 mm to 2 cm tan to brown oval stuck-on flat-topped verrucous
plaques on the back and abdomen, following skin tension lines
What are flat or raised?
Primary lesions
You cannot palpate the lesion with your eyes closed
Flat
Lesion is flat and <1 cm
Macule
Lesion is flat and >1 cm
Patch
You can palpate the lesion with eyes closed
Raised
Lesion is raised, <1 cm, and not fluid filled
Papule
Lesion is raised, >1 cm, but not fluid filled
Plaque
If you run your finger over the lesion but do not feel the
lesion, the lesion is what?
Flat spots
If you run your finger over the lesion and it is palpable
above the skin, it is what?
Raised Spots
Number
Lesions can be solitary or multiple. If multiple, record how many.
Also consider estimating the total number of the type of lesion you
are describing.
Size
Measure with a ruler in millimeters or centimeters. For oval lesions,
measure in the long axis, then perpendicular to the axis.
Shape
Some good words to learn are “circular,” “oval,” “annular” (ring-like,
with central clearing), “nummular” (coin-like, no central clearing),
and “polygonal.”
Color
- Use your imagination and be creative. Refer to a color wheel, if
needed. There are many shades of tan and brown, but start with tan,
light brown, and dark brown if you are having trouble. - Use “skin-colored” to describe a lesion that is the same shade as the
patient’s skin. - For red lesions or rashes, blanch the lesion by pressing it firmly with
your finger or a glass slide to see if the redness temporarily lightens
then refills.
Texture
Palpate the lesion to see if it is smooth, fleshy, verrucous or warty, or
scaly (fine, keratotic, or greasy scale).
Location
Be as specific as possible. For single lesions, measure their distance
from other landmarks (e.g., 1 cm lateral to left oral commissure).
Configuration
Patterns
Examining the Patient with Hair Loss
Inspect the scalp for erythema, scaling, pustules, tenderness,
bogginess, and scarring.
To examine the hair for shedding from the roots, perform a hair pull
test by
gently grasping 50 to 60 hairs with your thumb and index
and middle fingers, pulling firmly away from the scalp
If all the hairs
have telogen bulbs, the most likely diagnosis is what?
telogen effluvium
To examine the hair for fragility, perform the tug test by
holding a
group of hairs in one hand, pulling along the hair shafts with the
other; if any hairs break, it is abnormal.
Possible internal causes of diffuse nonscarring hair shedding in
young women are
iron-deficiency anemia and hyper- or
hypothyroidism
Focal patches may be
lost suddenly in
alopecia areata
What is seen in hypothyroidism?
Sparse hair
What is seen in hyperthyroidism?
Fine, silky hair
