integument

Question 1

What are the 5 layers of skin superficial to deep

Answer 1

Stratum corneum 
Stratum lucidum
Stratum granulosum
Stratum spinosum 
Stratum basale

Question 2

Thick skin characteristics and location

Answer 2

Found on the soles of the feet and palms of the hands
Thick stratum corneum
Stratum luciderm is present
Thicker stratum spinosum and granulosum

Question 3

This skin location and characteristics

Answer 3

All other skin

This stratum corneum, the stratum luciderm is absent, and it has a thinner strata spinosum and granulosum

Question 4

How many layers are present in thick skin

Answer 4

All 5

Question 5

How many layers are present in thin skin

Answer 5

Only 4. Luciderm isn’t present and it contains hair follicles, sebaceous glands, and sweat glands

Question 6

What cells are present in the stratum basale

Answer 6

Basal cells: keratinocytes stem cells-mitotic, melanocytes
Langerhans cells
Markell cells

Question 7

What connects basal cells to the basement membrane

Answer 7

Hemidesmosomes

Question 8

What connects adjacent cells to each other in the basale layer

Answer 8

Desmosomes

Question 9

What cells compose the stratum spinosum and what is their function

Answer 9

Keratinocytes: produce keratin (bundles of tonofilament) and lamellar bodies containing lipids/take in melanin (pigment) from melanocytes cytoplasmic processes

Attached to each other by desmosomes

Question 10

What do desmosomes connect to in keratinocytes

Answer 10

They connect to intracellular tonofilaments

Question 11

What is the composition of the stratum granulosum

Answer 11

Flattened keratinocytes that are dying and start to lose organelles, nucleus, and melanin granules. Lamellar bodies containing lipids released into extra cellular space forms a water barrier

Question 12

What is the composition of the stratum luciderm

Answer 12

Its only found in thick skin and is dead flattened keratinocytes filled with keratin and devoid of organelles and nucleus

Question 13

What is the composition of the stratum corneum

Answer 13

Dead keratinocytes called squames completely filled with keratin aggregated by filigrin. Surface squames are flaked by abrasion

Question 14

Epidermal cell types

Keratinocytes

Answer 14

Primary cell type from base to surface, produce keratin from tonofilaments and keratohyalin granules, and become squames in the cornified layer

Question 15

Epidermal cell types

Melanocytes

Answer 15

Derived from the neural crest, produce meanin that is transferred to keratinocytes, have a clear cell cytoplasm, and are only found in the basal layer.

Question 16

Melanin production

Answer 16

Tyrosinase made in the rER, packaged into vesicles by the golgi, and fuse with melanosome vessicles.
Tyrosine->DOPA->melanin via tyrosinase which is activated by UV light

Tanning increases melanin production not melanocytes

Question 17

Where is melanin stored

Answer 17

Stored in membrane bound granules in cytoplasmic processes

Question 18

Describe the melanin granule transfer process

Answer 18

Meanocyte cytoplasmic process that extend between keratinocytes containing the melanin granules allow the granules to be phagocytosed into keratinocytes.

Question 19

Epidermal cell types

Langerhans cells

Answer 19

Antigen presenting cell of the immune system, have a clear cytoplasm and are found in all layers

Question 20

Epidermal cell types

Markell cells

Answer 20

Discriminative touch receptor, clear cytoplasm, and found only in the basal layer of the skin

Question 21

Epidermal cell types

Stem cells

Answer 21

Dividing stem cell in basal layer of all skin

Question 22

Hair follicle layers

Superficial to deep

Answer 22

Connective tissue sheath
Glassy membrane (thick basement membrane)
External root sheath (downgrowth of the epidermis)
Internal root sheath
-surrounds the beginning of the hair shaft
-ends at the level of the sebaceous glands
Shaft

Question 23

Hair shaft cuticle

Answer 23

Layers of overlapping dead squamous cells

Question 24

Hair shaft cortex

Answer 24

Cuboidal cells
Keratinized portion of the hair shaft
Contain melanosomes

Question 25

Hair shaft medulla

Answer 25

Found only in thick hair

Large vacuolated cells