Ch 5

Question 1

What are the layers of the skin?

Answer 1

Epidermis

Dermis

Subcutaneous’

Question 2

What is the location and function of the stratum corneum?

Answer 2

Most superficial layer of the epidermis, consists of flattened and dead epithelial cells that have accumulated large amounts of keratin. Keratin is water resistant, and forms the basic structure of hair, calluses, and nails.

Question 3

What is the location and function of the stratum germinativum?

Answer 3

Also known as the stratum basale, it is the layer where new cells are generated and begin to grow. It also contains melanocytes which synthesize melanin, a yellow-brown to black pigment that colors the epidermis.

Question 4

What is the function of melanocytes?

Answer 4

Manufacture and store melanin.

Cells whose cytoplasmic processes extend between epithelial cells in this layer, and receptors that provide information about objects touching the skin.

Melanocytes synthesize melanin, a yellow-brown to black pigment that colors the epidermis.

Question 5

What is the function of melanin?

Answer 5

Melanin helps prevent skin damage by absorbing ultraviolet radiation before it reaches the deep layers of the epidermis and dermis.

Question 6

What is the function of hair and nails?

Answer 6

Hair:
Protects the scalp
Insulates the skull
Guards the nostrils and external ear canals
Provides early-warning system

Nails:

Nails form at the fingers and toes, where they protect the exposed tips and help limit their distortion when you grasp an object, climb a tree, run, or apply pressure in other ways.

Question 7

What is the functions of secretions of the sebaceous glands, and the apocrine, and merocrine glands?

Answer 7

Sebaceous glands:Discharge a waxy, oily
secretion (sebum) into hair follicles

Apocrine: sweat glands in the Armpits, around the nipples, and in the groin.

Merocrine sweat glands: also called eccrine sweat glands, palms and soles have the highest number

Merocrine sweat glands are coiled tubular glands that discharge their secretions directly onto the surface of the skin.

The primary functions of their secretions, called perspiration, are to cool the surface of the skin and reduce body temperature.

Question 8

Describe how the arterioles in the dermis respond to heat, cold, and stress?

Answer 8

Warm weather, fever - arterioles dilate

Frightened, cold weather – arterioles constrict

Question 9

Define subcutaneous tissue and its functions

Answer 9

Fat cells for insulation

Fibrous connective tissue to keep the skin in place

Question 10

Name the tissues that make up the subcutaneous tissue and describe their functions

Answer 10

Areolar tissue with many fat cells, these tissues provide infants and spa;; children with a layer of baby fat which helps reduce heat loss.

Also good for subcutaneous injections using a hypodermic needle.

Question 11

Describe the relationship between vitamin D, skin, and sunshine

Answer 11

Vitamin D helps intestinal absorption of calcium, magnesium, and phosphate. Two major forms are D2 and D3. These are essential to maintain skeletal calcium balance.

When exposed to UV, epidermal cells in the stratum spinosum and stratum germinativum (basal) covert a steroid related to cholesterol into vitamin D.