2 Dermatology Flashcards
Functions of epidermis?
- barrier from environment
- waterproofing
What is in the dermis?
- blood vessels
- hair follicles
- sebaceous glands
- sweat glands
- nails
- apocrine glands
What is in the subcutaneous (hypodermis)?
-subcutaneous fat and connective tissue
conserves heat
What are the layers of epidermis?
“can lucy get some balm”
- Stratum corneum: superficial with shedding dead skin
- Stratum lucidum: layer found on palmar and plantar surface
- Stratum granulosum: keritinization
- Stratum spinosum: spiny-chaped cells (strength/flexible)
- Stratum basale: cells germinate: keratinocytes
What are the 4 types of cells within the epidermis?
- keratinocytes
- melanocytes
- merkel cells
- langerhans cells
what are 3 layers of dermis?
-papillary dermis
superficial dermis
comprised of a loose network of collagen buncles
-reticular dermis
deep dermis
comprised of densely packed and thick collagen bundles
-ground substance
What is the function of eccrine glands and where?
- produce sweat
- cover most of the body
- abundant on palms, soles and forehead
- release salt and water to keep body cool
- does not cause odor (does when mixed with bacteria on skin surface)
- Duct opens in pore at skin’s SURFACE
What is the function of apocrine glands and where?
-produce thick clear odorless fluid (unless bacteria on surface breat them down and make odor)
-concentrated in axillary and genital regions
-Secretes into the SAC of hair follicle
-triggered by nervous system:
stress, exercise, hormones, emotion
What are two types of hairs and what is the bulb?
-vellus hairs: short and fine (forehead)
-Terminal hairs: long and thick (scalp/axillae)
-Bulb: enlargement at the base of follicle
matrix cells at inferior aspect of bulb
melanocytes within matrix contribute to pigment
What are morphologic characteristics of skin leasons?
- distribution
- shape/arrangement
- border/margin
- pigmentation/color
- palpation
Distribution- what does localized mean?
lesions appear in one small area
Distribution- what does regional mean?
lesions appear in a specific region of the body
Distribution- what does generalized/disseminated mean?
lesions appear widely distributed or in multiple areas simultaneously
What is common with distribution of flexors?
atopic eczema
What is common with distribution of extensors and scalp?
psoriasis
What is common with seborrhoeic distribution?
seborrhoeic dermatitis on scalp and upper chest
What is common with sun-exposed sites?
light sensitive disorders
What does morbilliform shape mean?
- measles-like
- erythematous maculopapular lesions that become confluent on the face and body
What are the ABCDEs of melanoma?
- A: asymmetry
- B: borders (irregular)
- C: color (variegated)
- D: diameter
- E: evolution or elevation
What is a macule?
-flat, non-palpable
*< 1 cm in diameter
-circumscribed color change
-ex. freckles (ephelides)
1
What is a patch?
-flat, non-palpable
-can have irregular shape
* > 1 cm in diameter
-often hypo or hyperpigmented
-ex. cafe au lait
1
What is a papule?
-Palpable, firm
*< 1 cm in diameter
-circumscribed
-can be flesh colored, red, brown
-may be confluent
-ex. seborrheic keratosis
1
What is a plaque?
-elevated
-firm
-palpable
* > 1 cm in diameter
-ex. psoriasis
1
What is a nodule?
-elevated
-circumscribed
*often > 1.5 cm in diameter
-deeper and firmer than papule
-can be compressible, soft, rubbery, or firm to palpation
-ex. epidermoid inclusion cyst
1
What is a tumor?
-a large nodule
-deeper in the dermis
* > 2 cm in diameter
-ex. lipoma (benign subcutaneous soft tissue tumor)
1