Integumentary System and Dermatopathology Flashcards
1
Q
What are some of the many functions of the skin?
6
A
- Prevents fluid loss
- Protection barrier
- Area for heat exchange
- Harbors immune cells that protect against invading microorganisms
- Neurological receptor relay system:
- Touch, pressure, temp, pain - Vitamin D synthesis
2
Q
- What does the epidermis cover?
- Composed of four different cell types. What are they?
A
- Covers the entire body
- Composed of four different cell types
- Keratinocytes (further categorized into the “stratum” layers)
- Melanocytes
- Merkel’s Cells (basal layer of epidermis)
- Langerhans’ cells
3
Q
- What is the predominant cell of the epidermis?
- Change size and shape as they move superficially, replacing what?
- Produces fibrous protein called keratin which is what?
- Structural protein of what?
A
- Keratinocytes
- cells lost during normal cell shedding
- which is essential to the protective function of the skin and is the
- structural protein of hair and nails
4
Q
What are the five separate layer of the epidermis?
A
Five separate layers:
- Stratum germinativum or stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
5
Q
Describe the following skin layers:
- Stratum germinativum or stratum basale?
- Stratum spinosum?
- Stratum granulosum?
- Stratum lucidum?
- Stratum corneum?
A
- Single layer of columnar cells, undergo mitosis, no migration
- Two to four layers, cells differentiate
- Only a few layers, most differentiated (some losing cytoplasm, others continue to synthesize keratin)
- Thin, transparent layer mostly confined to the palms of the hands and soles of feet, transitional cells
- Many layers (15-100 layers depending on location), dead squamous-type keratinized cells
6
Q
- Melanocytes are where?
- What do they do?
- Each melanocyte supplies several keratinocytes with melanin through what?
A
- Located at or in the basal layer
- Pigment-synthesizing cells (produce melanin)
- cytoplasm-filled extensions
7
Q
- Ability to synthesize melanin depends on the ability of the melanocytes to produce the enzyme ________.
- What if you had a genetic defect where you lacked this enzyme?
A
- tyrosinase (converts amino acid tyrosine to precursor of melanin)
- Albinism
8
Q
Melanocytes:
- What increases production of melanin?
- Primary function is to do what?
- What about melanocytes makes people light skin or darker skinned?
- All people, regardless of skin color, have relatively few or no melanocytes where?
A
- ***Exposure to UV rays increases production of melanin
- Primary function is to protect from UV rays (melanin absorbs and scatters radiation)
- Dark-skinned and light-skinned people have same amount of melanocytes (efficiency of production and shipping differs however)
- in palms of hands or soles of feet
9
Q
- What are the least densely populated cells of the epidermis?
- These function as what?
- Where would you suspect these cells to be most prominent?
A
- Least densely populated cells of the epidermis
- Function as mechanoreceptors (touch receptors)
- Finger tips
10
Q
- What are Langerhan’s Cells? Where are they?
- Describe the amount to kerotinocytes?
- What are do they do?
A
1.
- ***Immunologic cells responsible for recognizing foreign antigens harmful to the body
- Scattered in the suprabasal layer of the epidermis
2. Few in number compared to keratinocytes
3. Bind antigen to their surface, process it, send it on to regional lymph nodes
11
Q
- What is the dermis?
- Mostly composed of what?
- Also composed of what? 3
A
- Connective tissue layer separating the epidermis from the subcutaneous fat layer
- Mostly composed of collagen (major stress-resistant material of the skin)
- Also composed of:
- Variety of immune cells
- Nerves (wide distribution of receptors for touch, pressure, heat, cold, and pain)
- Blood vessels (dermis is richly supplied by arteriovenous anastomoses.
12
Q
- Subcutaneous tissue consists primariliy of what?
- What two structures extend to this layer?
A
- Consists primarily of fat and connective tissues that lend support to the vascular and neural structures supplying the dermis and epidermis
- Eccrine glands and deep hair follicles extend to this layer
13
Q
What are skin appendages? 4
A
- Sweat Glands
- Sebaceous Glands
- Hair
- Nails
14
Q
What are the two types of sweat glands?
A
- Eccrine (merocrine) sweat galnds
- Apocrine sweat glands
15
Q
Eccrine (merocrine glands)
- Located where?
- Originate where?
- Open directly to where?
- Primary function?
Apocrine sweat glands
- Located where and what do they look like?
- OPen through where?
- Secrete what kind of substance?
- Sterile until what?
- Function and location? 3
A
Eccrine (Merocrine) sweat glands
- Located over entire body surface,
- originate in dermis and
- open directly to the skin surface
- Primary function is to transport sweat to body surface to regulate body temperature (through what process- evaporation from the skins surface causes cooling)
Apocrine sweat glands
- Less numerous, larger, located in deep dermal layer
- Open through a hair follicle (so where would they primarily be found- where there is hair :P)
- Secrete more of an oily substance
- ***Sterile until mixed with bacteria
- -Axilla, areola, genetalia, (sweat glands, earwax, breast milk)
16
Q
Apocrine or Mericrine?
A
Apocrine
17
Q
Which is apocrine and which is eccrine?
A
Eccrine 1
Apocrine 2
18
Q
Sebaceous Glands
- Located where? Except (3)?
- Secrete a mixture called sebum which is composed of what? 3
- Function?
- Realtively inactive until when?
- Amount of sebum produced directly associated with what?
- What sex gland influences gland size?
A
- Located over the entire skin surface except for the palms, soles, and sides of feet
2.
- lipids,
- cholesterol, and
- other substances
3. Function is to lubricate hair and skin
4. Relatively inactive until adolescence
5. gland size
6. Androgens/testosterone
19
Q
- Most hair follicles are associated with what?
- Entire hair structure consists of what? 4
A
- Most hair follicles associated with sebaceous glands (the pilosebaceous unit)
- Entire hair structure consists of
- Hair follicle and hair shaft
- Sebaceous gland
- Hair muscle (arrector pili muscle)
- And sometimes an apocrine gland
20
Q
- The hair shaft is mostly composed of the fibrous protein…?
- Undergoes cyclic______?
- Hair follicles work_________?
- Human beings shed hair__________?
- What determines if a hair is shed? 3
- What determines the length of hair?
A
- Kerotin
- shedding
- independently
- asynchronously
- stress, drugs or if it reaches a certain length
- Genetic
21
Q
- Vascular network at the site of the ___________nourishes and maintains the hair follicle.
- Melanocytes located in the bulb determine what?
- Arrector pili muscle is located under the___________?
- This causes_________?
A
- follicular bulb
- hair color
- sebaceous gland
- goose bumps
22
Q
Nails
- What are they made of?
- Function?
- Grows how?
- Floor of the groove is the ________, which is the germinal region of the_________?
- Nail plate lies in the_______?
- Medical term for cuticle is_________?
A
- Hardened keratinized plates
2.
- Protects fingers and toes
- Enhances dexterity
3. Grows from curved transverse groove called nail groove
4. nail matrix, nail plate
5. nail bed
6. eponychium
23
Q
Rash
- Defined how?
- What kind of patterns? 2
- Evaluate? 3
A
- Change of the skin affecting color, appearance or texture.
- Localized or affects all the skin.
- Evaluate:
- Appearance
- Distribution
- Symmetry
24
Q
Manifestations of Skin Disorders
- Primary lesions arise from where?
- Secondary lesions arise from where?
A
Primary Lesions
- Arise from previously normal skin
Secondary Lesions
- Created by another process such as scratching or infection
25
Q
Types of Primary Lesions?
10
A
- Macule,
- Patch
- Papule,
- Plaque,
- Nodule,
- Tumor,
- Wheal
- Vesicle,
- Bulla,
- Pustule
26
Q
Describe each of the following?
- Macule,
- Patch
- Papule,
- Plaque,
- Nodule,
- Tumor,
- Wheal
- Vesicle,
- Bulla,
- Pustule
A
27
Q
What is a macule?
A
Circumscribed flat lesion less than 1cm
28
Q
What is a patch?
A
Same description as macule but >1cm
29
Q
- What is a papule?
- May become confluent and become a what?
A
- Elevated solid lesion with variable color less than 0.5cm
- plaque