Anatomy Honors Unit 4 Study Guide Answers

Unit 4 Lecture Study Guide

Use the lecture folder to help you complete this guide. The more detail you can provide the better prepared for the test you will be.

What is the integumentary system and its primary characteristics? Integumentary system is the skin and its derivatives, who protect external protection for the body. Primary characteristics: covers the entire body, accounts for about 7% of the total body weight, pliable(yet durable), thickness:1.5 to 4.0 mm, and is composed of the epidermis and dermis

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

Chemical Barriers (skin secretion and melanin), Skin secretions (acid mantle)

Low pH and sebum slow bacterial growth on skin surface

Human defensin – natural antibiotic

Cathelicidins – proteins that prevent Strep A infection in wounded skin

Melanin – chemical pigment that prevents UV damage

Physical/Mechanical Barriers – continuity of the skin and hardness of keratinized cells

Continuity prevents bacterial invasion

Glycolipids prevent diffusion of water and water-soluble substances between cells

Substances that are able to penetrate the skin:

Lipid-soluble substances (i.e., oxygen, carbon dioxide, steroids, and fat-soluble vitamins)

Oleoresins of certain plants (ex. Poison ivy and poison oak)

Organic solvents (ex. Acetone, dry cleaning fluid, and paint thinner)

Salts of heavy metals (ex. Lead, mercury, and nickel)

Penetration enhancers

Biological Barriers – Langerhans’ cells, macrophages, and DNA

Langerhans’ cells in epidermis present antigens to lymphocytes

Dermal macrophages (2nd line of defense) – attack bacteria and viruses that have penetrated the epidermis

DNA structure – the electrons in DNA absorb UV radiation and converts it to heat

Body Temperature Regulation

Production of copious amounts of sweat to dissipate heat

Constriction of dermal blood vessels to retain heat

Cutaneous Sensation – cutaneous...