Unit 4 Study Guide

What is the integumentary system and its primary characteristics?

-The skin and its derivatives (sweat and oil glands, hairs, and nails)

-Provides external protection for the body.

Describe and give at least one example of each of the functions of the integumentary system.

1. Protection

a. Chemical Barriers (skin secretion and melanin)

2. Body Temperature Regulation

a. Production of copious amounts of sweat to dissipate heat

3. Cutaneous Sensation – cutaneous sensory recptors (nervous system)

a. Meissner’s corpuscle and Merkel cells – detect changes in pressure

4. Metabolic Functions

a. Synthesis of Vitamin D – increases calcium absorption in the body

5. Blood Reservoir – vasoconstriction and vasodilation

6. Excretion – elimination of nitrogen-containing wastes, salt, and water

Differentiate between chemical, physical/mechanical and biological barriers provided by the integumentary system. Be sure to provide a minimum of one example for each. Chemical Barriers (skin secretion and melanin) Physical/Mechanical Barriers – continuity of the skin and hardness of keratinized cells Biological Barriers – Langerhans’ cells, macrophages, and DNA

Create a chart that helps you differentiate the epidermis and dermis. Be sure to include things such as cell composition, cell populations and layers.

a. Epidermis

i. Composed of epithelial tissue (keratinized stratified squamous)

ii. Cell population:

1. Keratinocytes (majority) – produce keratin

2. Melanocytes – synthesize melanin .

3. Langerhans’ cells (aka epidermal dendritic cells) – macrophages

4. Merkel cells – sensory reception

iii. Subdivided into four or five distinct layers

1. Stratum basale (aka, stratum germinativum) – deepest layer

2. Stratum spinosum

3. Stratum granulosum

4. Stratum lucidum (thick skin only)

5. Stratum corneum – outermost layer

b. Dermis

i. Composed of fibrous connective tissue

ii. Cell populations

1. Fibroblasts producing a semi-fluid...