Lecture 20: Anatomy and Physiology II (integumentary system)

Question 1

What is the epidermis?

Answer 1

The outer layer of the skin

Question 2

What are the stratums in the epidermis in order from deepest to outer layer?

Answer 2

1. stratum basale?
2. stratum spinosum
3. stratum granolsum
4. stratum lucidum
5. stratum corneum

Question 3

What is the stratum basale?

Answer 3

It is the deepest layer that is nourished by blood from the dermis. Also, the stem cells continually divide and daughter cells move upward when nourished. However, as they move upward, they die off due to decrease in nutrients.

Question 4

What is the stratum spinosum?

Answer 4

It is the stretchy layer that anchors junctions(desmosomes) and intermediate filaments attach to cells and keep them from stretching apart

Question 5

What is the stratum granulosum?

Answer 5

It is the transform layer where the cells flatten and nuclei/organelles disintegrate. This is due to keratinization where cells fill with keratin and release water resistant glycolipid

Question 6

What is stratum lucidum?

Answer 6

It is the thin layer where there is dead keratinocytes and keratinization is partially complete

Question 7

What is the stratum corneum?

Answer 7

It is a thick layer of keratinocytes and are dead skin dead cells. Keratin is tough and protects the skin from abrasion and penetration. The glycolipid are waterproof cells and there is a minimum of dead skin cells shedding at 50k/min

Question 8

What happens to the rate of cell division when the skin is rubbed and pressed regularly?

Answer 8

Rate of cell division increases and causes a callus or a thick area of keratinized skin

Question 9

What are some cell types?

Answer 9

1. keratinocytes
2. melanocytes
3. melanosome
4. skin color

Question 10

What are keratinocytes?

Answer 10

Skin cells

Question 11

What are melanocytes?

Answer 11

Pigment cells that absorb UV radiation and protect against DNA damage

Question 12

What are melanosome?

Answer 12

Pigment granule that can transfer to keratinocytes

Question 13

What is skin color?

Answer 13

Where people have similar number of melanocytes. However, color is due to the amount of melanin, size, and distribution of melanosomes. Also, sunlight stimulates melanin production

Question 14

What is the dermis?

Answer 14

The inner layer below the epidermis

Question 15

How is the dermis divided?

Answer 15

1. papillary
2. reticular

Question 16

What is the papillary layer?

Answer 16

The thing layer that has dermal papillae that are uneven projections. They form ridges in the skin like fingerprints and hand. Also, has areolar tissue that is interlacing collagen and elastic fibers loosely woven. Also, have dermal blood vessels that supply nutrients to skin cells and regulate body temperatures. They dilate to release heat(more flow to skin) or constrict to retain heat(less flow to skin).

Question 17

What is the reticular layer?

Answer 17

The thick layer that has dense irregular connective tissue that is closely packed bundles of interlacing collagen fibers. Also provide toughness and elasticity.

Question 18

What are some events of aging?

Answer 18

Rate of epidermal cell replacement slows and skin thins. There is a lubricant deficiency where the skin is dry,itchy, and elastic fiber clump