Lesson 1 notes

Question 0

What is the thickness of skin?

Answer 0

0.5 to 3 mm

Question 1

What is the surface area of skin?

Answer 1

3000 square inches

Question 2

How many cells are contained in one square inch of skin?

Answer 2

3 million cells

Question 3

What are the functions of skin?

Answer 3

Protect against infection, desiccation, harmful light rays
Maintain body temp
Receive stimuli from environment
Stores chemical compounds
Excretes waste products
Synthesizes vitamin D

Question 4

Name the thinner outer layer of the skin.

Answer 4

Epidermis

Question 5

How many layers comprise the epidermis?

Answer 5

4 (palms of hands and feet have 5)

Question 6

Which layers of the epidermis regenerate the cells of the epidermis?

Answer 6

Stratum Basale

Stratum spinosum

Question 7

What is the waterproofing protein that forms in cells as they move towards the surface of the epidermis?

Answer 7

Keratin

Question 8

What is the outermost layer of the epidermis?

Answer 8

Stratum corneum

Question 9

How often is an epidermal cell shed and regenerated?

Answer 9

28-30 days

Question 10

How many rows of cells are in the outermost layer of the epidermis?

Answer 10

25 to 30 rows

Question 11

What are epidermal cells called?

Answer 11

keratinocytes

Question 12

What other cells are found in the epidermis and are protective?

Answer 12

melanocytes and langerhans cells

Question 13

What layer of skin is deep to the epidermis?

Answer 13

Dermis

Question 14

What does the dermis contain?

Answer 14

blood vessels, nerves, glands, hair follicles

Question 15

What are the three appendages of the skin?

Answer 15

hair
glands
nails

Question 16

What is the soft hair that covers the body?

Answer 16

Vellus

Question 17

What do appendages develop from?

Answer 17

Embryonic epidermis

Question 18

What is the coarse hair that develops at puberty?

Answer 18

terminal also includes hair on scalp and eyebrows

Question 19

What are the three parts of a hair?

Answer 19

shaft
root
follicle

Question 20

What layer of the skin creates a hair follicle?

Answer 20

The epidermis

Question 21

What structures are associated with hair follicles?

Answer 21

Sebaceous glands

arrector pili muscles

Question 22

What glands are associated with the skin?

Answer 22

Sebaceous glands

Sweat glands

Question 23

What are the two types of sweat glands?

Answer 23

apocrine - develop at puberty, located in the axilla, pubic region, and breast areolae.
eccrine - distributed throughout the skin

Question 24

What is the function of a sebaceous gland?

Answer 24

secrete sebum (oil) which protects the hair and skin from becoming too dry

Question 25

What are the parts of the nail?

Answer 25

``` free edge nail body nail root lunula (white area at proximal end) cuticle (epidermis around the nail) nail bed (epidermis under the nail) ```

Question 26

What three things determine skin color?

Answer 26

Melanin Carotene Blood in the Capillaries

Question 27

What is a freckle?

Answer 27

Melanin that forms in patches

Question 28

How does UV radiation affect melanocytes?

Answer 28

It increases enzymatic activity which produces more melanin. Eventually, epidermal cells take up the melanin by phagocytosis and tanning has occurred.

Question 29

What pigment is found in people of Asian decent?

Answer 29

Carotene

Question 30

What is an example of an epidermal ridge?

Answer 30

fingerprints

Question 31

What is a line of cleavage?

Answer 31

predominant direction in which collagenous fibers run. | surgeons attempt to follow these lines to reduce scarring.

Question 32

At what time do you do a dermatological exam?

Answer 32

The same time you do the history.

Question 33

Gram Stain

Answer 33

performed on lesions suspected of bacterial infection. | Guides antibiotic selection

Question 34

Tzanck smear

Answer 34

Performed on lesions suspected of viral infection. | Positive result when giant, multinucleated cells are identified

Question 35

KOH prep

Answer 35

Performed on lesions suspected of fungal infection. Septated - tube-like structures - dermatophyte infection (tinea) Budding - sausage-like structures - candidal infection

Question 36

Direct examination of pathogen

Answer 36

Done in the case of scabies. | Mites, eggs, and feces can all be seen

Question 37

Cultures

Answer 37

Done to identify all types of pathogens. | Generally include a sensitivity, to show which antibiotic will be effective.

Question 38

Punch Biopsy

Answer 38

Cut through epidermis, dermis, and subcutaneous tissues. | Often utilized if the entire lesion cannot be easily removed, and suspected to be inflammatory.

Question 39

Wedge (excisional) Biopsy

Answer 39

Cut through the epidermis, dermis, and subcutaneous tissues. | Method of choice for most neoplastic processes.

Question 40

Shave Biopsy

Answer 40

Cut through the epidermis and dermis only. | Useful for lesions that are limited to the epidermis.

Question 41

Tests for allergic sensitization identification:

Answer 41

Patch testing Photopatch testing Prick testing RAST (radioallergosorbent test)