HWA PPx 3 Hair Skin and Nails

Question 1

Layers of the Integumentary System.

Answer 1

Epidermis
Dermis
Subcutaneous Layer

Question 2

What is the function of the skin?

Answer 2

Two large functions: protection and adaptation

Protection & healing
- Trauma, pathogens, dirt, damaging light rays
- Wound healing (cuts, burns, etc.)

Adaptation
- Heat and cold regulation, as well as to prevent fluid loss

Question 3

When does hair develop for infants? What is the downy hair they have at birth called?

Answer 3

Hair develops at 3 months gestation – lanugo present at birth (fine downy hair)

Question 4

What is Vernix Caseosa?

Answer 4

Thick, cheesy substance composed of sebum and epithelial cells

Serves as protection and natural moisturizer while in utero

Question 5

What skin functions are not fully developed in infants?

Answer 5

Thin, smooth, and elastic. More permeable = greater risk for fluid loss

Temperature regulation ineffective

Inefficient subcutaneous layer – lack of cold protection (skin cannot contract and shiver)

Eccrine glands without response at birth, then minimal response through childhood

Sebaceous glands active only first couple weeks of life, then inactive until puberty

Question 6

What developmental changes occur in children?

Answer 6

Epidermis thickens, toughens and darkens

Hair growth accelerates

Puberty:
- Increased secretion of apocrine sweat glands
- Response to heat and emotional stimuli (body odor develops)
- Sebaceous glands more active
- Skin oily in appearance and acne develops
- Subcutaneous fat increases (especially in females)

Skin-evident secondary sex characteristics:
Breast tissue develops
Pubic and axillary hair develops in males and females; facial hair in males