Lecture 8 - Integument

Question 1

Layers of skin

Answer 1

Epidermis, dermis, and hypodermis (not apart of the integument)

Question 2

What is present in thick skin

Answer 2

thicker stratum corneum and a presence of a stratum lucidum

Question 3

4 Cells of the epidermis

Answer 3

keratinocytes, langerhan’s cells, merkel’s cells, and melanocytes

Question 4

keratinocytes

Answer 4

filled with keratin fibers (intermediate), most common in the epidermis. connected via desmosomes. 5 layers.

Question 5

Langerhan’s cells

Answer 5

derived from monocytes. can act as an APC and phagocytic cell

Question 6

Merkel’s cells

Answer 6

sensory and typically next to a nerve. Has dense core ganules (neurotransmitter granules) next to the nerve ending

Question 7

Melanocyte

Answer 7

produces the pigmentation of skin

Question 8

5 layers of thick skin from top to bottom

Answer 8

Stratum corneum, stratum lucidum, stratum granulosm, stratum spinosum, and stratum basale

Question 9

Most mitocially active layer

Answer 9

stratum basale and includes melanocytes

Question 10

Protein in desmosomes

Answer 10

cadherins

Question 11

Protein in hemidesmosomes

Answer 11

integrins

Question 12

Stratum spinosum apperance

Answer 12

spiny cell layer due to tissue shrinkage and connection of desmosomes. tonofibrils and cytokeratin filaments present

Question 13

Stratum granulosum appearance

Answer 13

due to keratohyalin (non-membrane bound granules) which bind to keratin. Lamellar granules (membrane) with lipids and is barrier to desiccation and water

Question 14

Non-living cell layers

Answer 14

Stratum lucidum and stratum corneum

Question 15

Layers in thin skin from top to bottoms

Answer 15

Stratum corneum, stratum granulosum, stratum spinosum, and stratum basale

Question 16

3 functions of the epidermis

Answer 16

abrasion resistance, physical-chemical barrier, and water proofing

Question 17

Melanocyte’s two pigments and enzyme

Answer 17

eumelanin (black) and pheomelanin (red). tyrosinase

Question 18

Where do melanocytes originate from?

Answer 18

neural crests

Question 19

Tyrosinase

Answer 19

synthesized in the RER. converts DOPA into doaquinone into melanin. stops when melanin becomes a granule

Question 20

Where do melanin granules get injected?

Answer 20

into keratinocytes’ cytoplasm.

Question 21

Role of melanin

Answer 21

protects the nuclear DNA from UV radiation

Question 22

Albinism

Answer 22

lack of tyrosinase activity. Cant make melanin

Question 23

T or F: skin color is due to the amount of melanin and carotene, not the number of melanocytes?

Answer 23

True

Question 24

BCC

Answer 24

originates from the stratum basale

Question 25

SCC

Answer 25

originates from a squamous keratinocyte

Question 26

Collagen type found in the basement membrane

Answer 26

Type 4 collagen

Question 27

Proteins and types of collagen seen on the dermal side of the dermal-epidermal junction

Answer 27

laminins, fibronectin, type 4 collagen, type 6 collagen

Question 28

2 layers of the dermis

Answer 28

papillary and reticular layer. Makes up the peg and socket which provides stability.

Question 29

Papillary layer

Answer 29

highly folded

Question 30

Reticular layer

Answer 30

dense irregular CT (type I collagen and fibroblasts), blood tissues (AV shunts), and elastic fibers

Question 31

Meissner's corpuscles

Answer 31

sensory for light touch. Found in the papillary layer. Part of the afferent system

Question 32

Arterio-venous shunts

Answer 32

short circulate blood, thus blood doesnt have to go through a capillary. control the blood going to the papillary layer (facilitates thermoregulation)

Question 33

Pacinian corpuscle

Answer 33

deep touch/pressure sensation. In the reticular layer. Part of the afferent layer.

Question 34

Hypodermis

Answer 34

superficial facia. adpiose tissue.

Question 35

Nail matrix

Answer 35

gives rise to the nail plate.

Question 36

Area under cuticle?

Answer 36

eponychium

Question 37

Area under the nail plate

Answer 37

Hyponychium and nail bed

Question 38

Hair is what in origin?

Answer 38

epidermal.

Question 39

Bulb contains what dermal tissue

Answer 39

fibroblasts and blood vessels. It is papilla.

Question 40

Germinal matrix

Answer 40

undergoing rapid proliferation of the forming hair cells. Sensitive to chemo

Question 41

Internal root sheath

Answer 41

stops at the sebaceous gland

Question 42

External root sheath

Answer 42

goes to the surface and becomes epidermis.

Question 43

Cuticle of hair

Answer 43

small barbs that prevent it from falling out

Question 44

Layer of hair from inner to outer

Answer 44

medulla, cortex, cuticle

Question 45

Arrector pili muscle

Answer 45

smooth muscle. when cold it will contract, straightening the hair and increasing insulation. (fight or flight)

Question 46

3 glands of skin

Answer 46

sebaceous, eccrine, and apocrine

Question 47

Sebaceous glands

Answer 47

secrets onto hair shaft. simple branched acinar gland. Holocrine mode of secretion of sebum

Question 48

Sebum

Answer 48

maintains stratum corneum, weak antibacterial/fungal activity

Question 49

Eccrine sweat gland

Answer 49

Merocine and secretes onto the surface. Dark and clear cells. Duct portion is stratified cuboidal cells. Secretions mainly protein free filtrate.

Question 50

Dark cells of eccrine gland

Answer 50

mucoid and antibacterial

Question 51

Clear cells of eccrine gland

Answer 51

produce sweat. have an increased surface area

Question 52

Apocrine sweat gland

Answer 52

merocrine and secretes onto the hair shaft. Larger diameter than eccrine glands. Found in auxillary areas. Only has dark cells (pheromones)

Question 53

What layer is responsible for wrinkles

Answer 53

Dermis - specifically the reticular layer.

Question 54

White part of the proximal nail fold?

Answer 54

Lunula

Question 55

Area that has stratified cuboidal epithelium?

Answer 55

Duct of the eccrine sweat gland