Chapter 5- Integumentary System

Question 1

What system is the first line of defense against a hostile surrounding environment?

Answer 1

Integumentary

Question 2

What are the two components of the cutaneous membrane (skin)?

Answer 2

Epidermis, dermis

Question 3

**Functions of skin

Answer 3

1. Protection of underlying tissues & organs
2. Excretion of salts, water, and organic wastes (glands)
3. Maintenance of body temp (insulation and evaporation)
4. Production of melanin
5. Production of keratin
6. Synthesis of Vitamin D3
7. Storage of lipids
8. Detection of touch, pressure, pain, temp
9. Coordination of immune response

Question 4

What kind of tissue makes up the epidermis?

Answer 4

Avascular Stratified Squamous Epithelium

Question 5

Thin skin

Answer 5

• covers most of the body

- has 4 layers of keratinocytes

Question 6

Thick skin

Answer 6

• covers palms of hands and soles of feet

- has 5 layers of keratinocytes

Question 7

5. Stratum Corneum

Answer 7

-Layer you see, flat dead cell, many layers thick, upper layers are continuously sluffed off

Question 8

4. Stratum Lucidum

Answer 8

ONLY FOUND IN THICK SKIN

Question 9

3. Stratum Granolusum

Answer 9

-Cells start to flatten, Plasma membrane becomes thicker, organelles and cell dies off

Question 10

2. Stratum Spinosum

Answer 10

• Spiny structure

- keratinocytes

Question 11

1. Stratum Basale

Answer 11

• Mitotically active cells
• Produce cells for all other layers
• Cuboidal shaped
• Contains melanocytes
• 1 layer of cells thick!

Question 12

Keratin

Answer 12

Tough, fibrous protein
Decreases water loss
Makes up hair and nails

Question 13

What produces orange-yellow pigment in skin?

Answer 13

Carotene

-carrots, sweet potatoes

Question 14

What produces red-yellow/brown-black pigment in skin?

Answer 14

Melanin

• melanocytes
• protects skin from sun damage

Question 15

Blood circulation

Answer 15

• Blood vessels dilate from heat, skin reddens

- Blood flow decreases, skin pales

Question 16

Cyanosis

Answer 16

• bluish skin tint

- caused by severe reduction of blood flow/oxygenation

Question 17

Jaundice

Answer 17

• yellow color

- buildup of bile produced by liver

Question 18

Vitiligo

Answer 18

• loss of melanocytes & color

- may develop when immune system malfunctions

Question 19

Basal Cell Carcinoma

Answer 19

• most common skin cancer
• originates in stratum basale in response to UV radiation
• virtually no metastasis and most ppl survive

Question 20

Malignant Melanoma

Answer 20

• cancerous melanocytes
• metastasize through lymphatic system
• detected early, 5-yr survival is 99%, detected until after metastasis, 5-yr survival is 14%

Question 21

ABCDE rule to detect melanoma

Answer 21

A: Asymmetry: the two sides of the pigmented area do not match
B: Border exhibits indentations
C: Color is black, brown, tan, and sometimes red or blue
D: Diameter is larger than 6 mm (size of pencil eraser)
E: Evolving

Question 22

Vitamin D3

Answer 22

-Epidermal cells produce CHOLECALCIFEROL (Vitamin D3) in the presence of UV radiation
-Liver and kidneys convert Vitamin D3 into Calcitriol
CALCITRIOL: Aids in absorption of calcium and phosphorus
Insufficient V.d3 can cause rickets

Question 23

Two layers of the dermis

Answer 23

2. Papillary: Areolar (arena for immune system), capillarys providing blood to epidermis
3. Reticular: Dense irregular connective tissue (collagen & elastic fibers), large blood vessels

Question 24

Dermal strength and elasticity

Answer 24

1. Collagen fibers
   - impart strength
   - provide flexibilty and resists punctures
2. Elastic Fibers
   - Permit stretching and then recoil to original length
3. Skin Turgor
   - result of the fibers & water content
   - Can be used to indication hydration levels

Question 25

**Blood osmolarity

Answer 25

normal 300 osmol above 300: Dehydrated - Hypotonic IV below 300: Overhydrated - Hypertonic IV

Question 26

Lines of Cleavage

Answer 26

clinically significant for surgery and wound healing parallel to cleavage: better healing, less scarring perpendicular to cleavage: remain open and more scarring

Question 27

Dermal blood supply

Answer 27

Cutaneous plexus: A network of arteries along the reticular layer Papillary plexus: Capillary network from small arteries in papillary layer

Question 28

Nerve fibers in skin control

Answer 28

Blood flow Gland secretions Sensory receptors

Question 29

Hypodermis (Subcutaneous Layer)

Answer 29

Made of elastic areolar and adipose tissues F: -Cushioning, energy storage, insulation Attaches to skin but allows independent movement

Question 30

Hair follicles

Answer 30

- produce hairs that protect skull | - produce hairs that provide delicate touch sensations

Question 31

Exocrine glands

Answer 31

- Assist in thermoregulation - Excrete wastes - Lubricate epidermis

Question 32

Nails

Answer 32

Protect and support tips of fingers and toes

Question 33

Functions of hair

Answer 33

protects and insulates guards openings against particles and insects sensory, sensitive to very light touch

Question 34

****Repair of the integumentary system

Answer 34

1. Inflammatory Phase - bleeding occurs at the site of injury immediately after the injury, and mast cells in the region trigger an inflammatory response 2. Migratory Phase - a scab forms and cells of the stratum basale are migrating along the edges of the wound. - phagocytic cells remove debris 3. Proliferation Phase - Epidermal cells migrated over the collagen fiber meshwork - fibrin clot dissolving 4. Scarring Phase - scab has been shed - Fibroblasts continue to create scar tissue