Skin

Question 0

What is the structure of the epidermis?

Answer 0

Stratified squamous EPITHELIUM with insoluable protein KERATIN (cornified)

Avascular; No blood vessels, activities via diffusion

Question 1

Stratum corneum

Answer 1

Uppermost layer of skin

Variations in this cause variations in thickness of skin

Question 2

Stratum basale

Answer 2

Stratum= layer
Basale= basal= rests on basement ️membrane

Question 3

Keratinocytes

Answer 3

EPIDERMIS- stratum basale

Give rise to (keratin cells) NEWEST cells pushed outward in cell division

Question 4

Melanocytes

Answer 4

EPIDERMIS- Stratum basale

-Produce pigment melanin

Question 5

Melanin

Answer 5

Pigment

Passed from melanocytes to keratinocytes through phagocytosis

Question 6

Merkel cells

Answer 6

EPIDERMIS- Stratum basale

-in conjunction with dermal nerve ending, form tactile receptor known as MERKEL disc!

Question 7

Merkel disc

Answer 7

In dermis

Tactile receptor formed by MERKEL cells and dermal nerve endings in epidermis stratum basale

Question 8

Stratum Spinosum

Answer 8

EPIDERMIS

• several layers of flat keratinocytes
• organelles degenerating
• spiny appearance as shrink; attached to each other by desmosomes

Question 9

Where in epidermis are Macrophages found?

Answer 9

Stratum Spinosum and stratum granulosum

Question 10

Stratum granulosum

Answer 10

EPIDERMIS

2-5 layers of cells with granules of keratohyalin

Question 11

Stratum Lucidum

Answer 11

EPIDERMIS

Thin, translucent zone (a lot of matrix) seen only in THICK skin, such as soles of feet

Question 12

Stratum Corneum

Answer 12

EPIDERMIS

Made up of 25-30 layers of dead keratinized cells

Waterproof, protective outer layer; thickest layer

Question 13

Subcutaneous layer

Answer 13

Area (layer) below the skin

Ex: a subcutaneous injection from dr.

Question 14

Exocrine gland

Answer 14

Any gland with a duct that reaches the surface

Ex: glandular epithelium

Question 15

Intra-

Answer 15

Within

Question 16

Inter-

Answer 16

Between/among

Question 17

What kind of cells make up the stratum basale?

Answer 17

A single layer of low columnar cells, rests on basement membrane

Question 18

What 3 cells can be found in the stratum basale in the epidermis?

Answer 18

Keratinocytes, melanocytes, and merkel cells

Question 19

What happens to melanin when a white person gets tan?

Answer 19

You make the melanin spread out more

Question 20

What happens to keratinocytes as they go from stratum basale to stratum Spinosum?

Answer 20

They flatten (in which organelles are degenerating) and make up several layers of the stratum spinosum

Question 21

How are the flattened keratinocytes in the stratum spinosum connected to each other?

Answer 21

By desmosomes, giving them a spiny appearance as they shrink

Question 22

What two cells are found in stratum

Spinosum if epidermis?

Answer 22

Keratinocytes and macrophages

Question 23

Macrophages

Answer 23

(Aka Langerhans cells)
In every area of the body just different names

Named this in stratum Spinosum and stratum granulosum of epidermis

Question 24

Whats keratohyalin

Answer 24

Will become keratin

Question 25

Dermal papilla

Answer 25

Structures of epithelium sticking down from epithelium in epidermis into CT of dermis like FINGERS More circuitry for diffusion from bottom-up

Question 26

What is the GENERAL structure of the dermis?

Answer 26

CONNECTIVE TISSUE Specifically, fibroconnective tissue w/ blood vessels, nerve endings, sweat glands, hair follicles, and nail roots

Question 27

What is the papillary layer of the dermis?

Answer 27

A zone of areolar tissue (loose CT) closest to epidermis, projecting hoard as dermal papillae. BLOOD VESSELS extend close to epidermis within papillae. Large # white blood cells (immune system)

Question 28

What is the reticular layer in the dermis?

Answer 28

Contains dense irregular CT Stretching this area is what causes stretch marks

Question 29

Linea albicantes

Answer 29

Stretch marks caused by tears in reticular layer of dermis

Question 30

Alb-

Answer 30

White

Question 31

How thick is the dermis?

Answer 31

1.0-2.0 mm thick

Question 32

How many cm are in 1 inch?

Answer 32

2.5cm

Question 33

Sebaceous gland

Answer 33

Next to hair; produce oil in hair (exocrine glands)

Question 34

Arrector pili muscle

Answer 34

Muscle that makes hair stand up

Question 35

Dermal BV dilation

Answer 35

Skin becomes red; (bc hot)

Question 36

Dermal BV constriction

Answer 36

BV constrict so we can keep warm when cold

Question 37

What are two other pigments beside melanin?

Answer 37

Carotene (Orange) | Jaundice (yellow)

Question 38

Hepatitis

Answer 38

Disease of the liver; causes jaundice (yellow skin)

Question 39

Hematoma

Answer 39

Bruise

Question 40

Erythema

Answer 40

Abnormal skin redness Can cause pallor

Question 41

Pallor

Answer 41

Pale/light skin

Question 42

Cyanosis

Answer 42

"Cyan"= blue | Blue skin; low oxygen (constrict BV)

Question 43

Hemiangiomas

Answer 43

Birthmarks

Question 44

Nevus

Answer 44

Moles on

Question 45

What makes skin a tough barrier?

Answer 45

Keratin and epidermal desmosomes (tight junctions that keep skin intact)

Question 46

What makes skin unfavorable for microbial growth?

Answer 46

Dry habitat and acid mantle of sweat

Question 47

Can water get through skin

Answer 47

No bc of keratin

Question 48

What two chemicals are involved in the production of vitamin D?

Answer 48

Dehydrocholesterol | Cholecalciferol

Question 49

Vitamin D synthesis

Answer 49

UV radiation penetrate dermis, reaches steroid: dehydrocholesterol (in blood). Converted to cholecalciferol. LIVER turns this into active vitamin D.

Question 50

What does vitamin D do for the body? I

Answer 50

Helps us to absorb calcium for nerves & muscles; phosphorous levels in body

Question 51

Do we receive oxygen through skin?

Answer 51

Small amount 1-2%

Question 52

Insensible perspiration

Answer 52

Sweat constant w|o noticing

Question 53

What are both hair (pili) and nails made of?

Answer 53

Hard KERATIN

Question 54

Lanugo

Answer 54

Fine, downy, no pigment Cover fetus

Question 55

Vellus

Answer 55

Fine unpigmented hair that covers most of body

Question 56

Terminal hair

Answer 56

Pubic hair/ men's facial hair

Question 57

Vibrissae

Answer 57

Short guard hairs in nose, ears ...

Question 58

Structure of hair in skin

Answer 58

Root, hair follicle, then shaft above skin

Question 59

What causes hair color?

Answer 59

Abundance of melanin

Question 60

Red hair contains ....

Answer 60

Trichosiderin

Question 61

Where is hair follicle

Answer 61

Dermis; has 2 layers

Question 62

Epithelial root sheath

Answer 62

Extension of epidermis

Question 63

What causes hair to grow?

Answer 63

Mitosis in stratum basale of epidermal root sheath

Question 64

Alopecia

Answer 64

Thinning of hair (age-related, other...)

Question 65

Hypertrichosis

Answer 65

Abnormal hair growth

Question 66

Two types of skin sweat glands

Answer 66

Merocrine | Apocrine

Question 67

Merocrine sweat glands

Answer 67

Watery sweat to cool off | Ducts to skin surface

Question 68

Apocrine sweat glands

Answer 68

Groin, breast.. Viscous, odorous, puberty, respond to stress Ducts lead to hair follicles

Question 69

Sebum

Answer 69

Produced by sebaceous glands (oil of cholesterol, fats, proteins, salts) to moisturize skin/hair Associated w| hair= ducts in hair follicle Not associated w| hair= ducts open on skin surface (lips, eyelids, labia minora)

Question 70

Cercuminous glands

Answer 70

Only in ear canal to produce cerumen (ear wax) Modified sweat gland

Question 71

Cerumen

Answer 71

Ear wax

Question 72

Why do women have more BV than men?

Answer 72

Skin thickens at puberty (blush easily ex)

Question 73

Senescence

Answer 73

Collagen breaks down

Question 74

What percentage of solid rumors are in epithelium?

Answer 74

70%

Question 75

Most frequent skin cancer

Answer 75

Basal cell carcinoma - seldom spreads - raised bump

Question 76

Squamous cell carcinoma

Answer 76

Skin cancer from stratum spinosum | -curable but can spread

Question 77

Deadliest, least common skin cancer

Answer 77

Melanoma

Question 78

Melanoma

Answer 78

Survival rate= less than 1% | Arises from melanocytes (preexisting mole)

Question 79

What goes to area of skin when cut?

Answer 79

Fibroblasts | Go to cut from dermis to lay down white collagen (scar tissue)

Question 80

Leading cause of accidental death

Answer 80

Burns

Question 81

1st degree burns

Answer 81

Only epidermis

Question 82

2nd degree burns

Answer 82

Upper dermis

Question 83

3rd degree burns

Answer 83

Destroy skin & sometimes deeper tissue

Question 84

Debridement

Answer 84

Cutting away dead tissue | essential in severe burns

Question 85

Autograft

Answer 85

Skin graft taken from same person

Question 86

Isograft

Answer 86

From identical twin

Question 87

Homograft

Answer 87

Unrelated person

Question 88

Heterograft/xenograft

Answer 88

Different animal