Integumentary System

Question 1

What is the largest organ of the body that accounts for 3-5 kg of body weight?

Answer 1

SKIN

Question 2

The Integumentary System is composed of the following:

Answer 2

1. Hair
2. Nails
3. Oil & Sweat Glands
4. Skin

Question 3

What are the 3 layers of the skin?

Answer 3

1. Epidermis
2. Dermis
3. Hypodermis

Question 4

Keratinocytes, Melanocytes, Langerhans cells, & Merkel cells are found in what layer of the skin?

Answer 4

EPIDERMIS

Question 5

Define Keratinocytes.

Answer 5

• building blocks of KERATIN = provide structure, durability, & waterproofing to hair, nails, & outer skin
• constantly dying and being replaced

Question 6

Define Melanocytes.

Answer 6

• spider-shaped cells
• synthesizes MELANIN = pigment that gives color to skin
  > color depends on cellular extensions and NOT to # of cells

Question 7

These epidermal cells are responsible for ingesting unwanted invaders and originate from bone marrow.

Answer 7

LANGERHANS CELLS

Question 8

These epidermal cells are also known as tactile cells that combine with nerve endings to create a sensory receptor for TOUCH.

Answer 8

MERKEL CELLS

Question 9

What is the difference between THICK & THIN Skin?

Answer 9

THICK SKIN
- tougher part found in palms and soles of feet
- has 5 epidermal layers

THIN SKIN
- found everywhere else
- has 4 epidermal layers

Question 10

How many layers does the skin have and what are they?

Answer 10

5 epidermal layers in THICK skin, but only 4 layers in THIN skin.

These layers are:
1. Stratum Corneum
2. Stratum Lucidum (for thick skin only)
3. Stratum Granulosum
4. Stratum Spinosum
5. Stratum Basale

Question 11

Define Stratum Corneum.

Answer 11

• outermost layer
• roughest = 20-30 sheets of dead keratinocyte cells

Question 12

Define Stratum Lucidum.

Answer 12

• a.k.a. “clear layer”
• 2 or 3 of clear, flat dead keratinocytes
• ONLY in THICK skin

Question 13

Define Stratum Granulosum.

Answer 13

• a.k.a. “granular layer”
• contains LIVING keratin
• grainy appearance due to compressed & flattened keratin

Question 14

Define Stratum Spinosum.

Answer 14

• a.k.a. “spiny layer”
• contain filaments that helps in holding each other

Question 15

Define Stratum Basale.

Answer 15

• a.k.a. “basal layer”
• deepest & thinnest
• contains SIMPLE COLUMNAR cells
• connects epidermis to dermis

Question 16

What are the characteristics of the Dermis?

Answer 16

• has collagen & elastin fibers for strength and elasticity
• has capillaries & blood vessels
• has nerve fibers for temp., pressure, and pain
• has hair follicles, oil & sweat glands that have ducts to the outside of the skin

Question 17

What are the layers of the Dermis?

Answer 17

1. Papillary layer
2. Reticular layer

Question 18

What is the papillary layer of the dermis?

Answer 18

• upper layer of dermis
• composed of thin sheet of areolar connective tissue with little peg-like projections called “dermal papillae”

Question 19

What are dermal papillae?

Answer 19

Dermal Papillae form friction ridges in thick skin by pressing up the epidermis to help in gripping surfaces

Question 20

What is the reticular layer of the dermis?

Answer 20

• thicker layer
• 80% of the dermis
• made of dense irregular connective tissue

Question 21

Where are the nerve fibers and capillaries distributed in the skin?

Answer 21

In the PAPILLARY & RETICULAR Layer of the Dermis

Question 22

Define the Hypodermis.

Answer 22

• a.k.a. subcutis
• mostly adipose connective tissue
• provides insulation, energy storage, shock absorption, & anchor skin