Skin

Question 1

Define the skin.

Answer 1

Largest organ of body that acts as a primary immune defense.

It’s waterproof and constantly sheds its cells to replenish with new ones.

Question 2

List the different layers of the skin

Answer 2

Epidermis
Dermis
Hypodermis

Question 3

Describe the Epidermis layer

Answer 3

Avascular - lacking in blood vessels
Renewed every 1-2 months
Contains melanocytes (melanin forming cells)

5 strata of squamous cells: 
Corneum 
Lucidum 
Granulosum 
Spinosum 
Basale

Question 4

Describe the Dermis layer

Answer 4

Thickest layer 
Loose connective tissue 
Network of nerves, capillaries etc. 
Protein fibres (collagen and elastin) 
Papillary layer - dermal papillae anchored to rete ridges to prevent blisters 
Reticular dermis - base

Question 5

Describe the Hypodermis layer

Answer 5

Subcutaneous layer
Fat storing cells
Insulation/cushion

Question 6

What are rete ridges (found in the dermis layer)?

Answer 6

epithelial extensions that project into the underlying connective tissue in both skin and mucous membranes

Question 7

What are dermal papillae for?

Answer 7

crucial in the formation of hair follicles

Question 8

Identify the functions of the skin.

Answer 8

Protection/barrier from pathogenic organisms
Thermoregulation 
Sensation 
Vitamin D synthesis 
Absorption 
Resistance to change (pH and temp.)

Question 9

List the factors which affect the skin.

Answer 9

Sunlight 
Hydration
Soap
Nutrition 
Medicine 
Circulation 
Age

Question 10

What can we do to ensure we take care of our skin.

Answer 10

Sunscreen
Plenty of water
Moisturize

Question 11

Describe the corneum layer of the epidermis

Answer 11

Exposed to environment

Helps prevent the penetration of microbes and the dehydration of underlying tissues

Protects more delicate layers of epidermis

Question 12

Describe the lucidum layer of the epidermis

Answer 12

smooth, seemingly translucent layer

found only in the thick skin of the palms, soles, and digits

Question 13

Describe the granulosum layer of the epidermis

Answer 13

grainy appearance

Cells generate large amounts of the proteins keratin

Question 14

Describe the spinosum layer of the epidermis

Answer 14

The keratinocytes in the stratum spinosum begin the synthesis of keratin and release a water-repelling glycolipid that helps prevent water loss from the body, making the skin relatively waterproof

Question 15

Describe the basale layer of the epidermis

Answer 15

deepest epidermal layer

dermal papillae are found here