Chapter 5 The Integumentary System

Question 1

Stratum corneum (keratin)

Answer 1

Outer layer of epidermis
Composed of dead, keratinized cells
Prevents loss or entry of water
If unbroken, prevents entry of pathogens & most chemicals

Question 2

Stratum germinativum (stratum basale)

Answer 2

Inner layer of epidermis
Continuous mitosis produces new cells to replace worn-off surface cells
Produces antimicrobial defensins
Cholesterol is changed to Vit D on exposure to UV rays

Question 3

Langerhans cells

Answer 3

Phagocytize foreign material & stimulate an immune response by lymphocytes

Question 4

Merkel cells

Answer 4

Receptors for sense of touch

Question 5

Melanocytes

Answer 5

Produce melanin on exposure to UV rays

Question 6

Melanin

Answer 6

Protects living skin layers from further exposure to UV rays

Question 7

Papillary layer

Answer 7

Contains capillaries that nourish the stratum germinativum

Question 8

Hair (follicles)

Answer 8

Eyelashes & nasal hair keep dust out of eyes and nasal cavities
Scalp hair provides insulation from cold for the head

Question 9

Nails (follicles)

Answer 9

Protect ends of fingers and toes from mechanical injury

Assist with picking up small objects; scratching

Question 10

Receptors

Answer 10

Detect changes that are felt as the cutaneous sense: touch, pressure, heat, cold, itch, pain

Question 11

Sebaceous glands

Answer 11

Produce sebum, which prevents drying of skin & hair & inhibits growth of some bacteria

Question 12

Ceruminous glands

Answer 12

Produce cerumen, which prevents drying of eardrum

Question 13

Eccrine sweat glands

Answer 13

Produce watery sweat that is evaporated by excess body heat to cool the body

Question 14

Arterioles

Answer 14

Dilate in response to warmth to increase heat loss
Constrict in response to cold to conserve body heat
Constrict in stressful situations to shunt blood to more vital organs

Question 15

Areolar connective tissue

Answer 15

Connects skin to muscles
Contains many WBCs to destroy pathogens that enter breaks in skin
Contains mast cells that release histamine, leukotrienes & other chemicals involved in inflammation

Question 16

Adipose tissue

Answer 16

Contains stored energy in the form of true fats
Cushions bony prominences
Provides some insulation from cold
Contributes to appetite
Contributes to use of insulin
Produces cytokines that activate WBCs
Brown & beige fat produce heat