Ch 16 The Integumentary System - Objectives

Describe four ways to protect skin from damage.

Keep skin clean, to prevent growth of pathogens. Clean and cover cuts and open wounds. Use cosmetics sparingly; remove daily. Dress appropriately for the weather. Eat a balanced diet; drink plenty of water and other fluids. Protect you skin from excessive sun; use sunscreen, wear long-sleeved clothing and a hat.

Explain the functions of keratin and melanin.

Keratin is waterproof and protects the skin. Melanin gives color to the hair, skin, and other structures of the body.

Name five changes that occur in aging skin.

Melanin is either lost or migrates and clusters in the epidermal layer. Epidermal and dermal layers flatten. There is loss of elasticity in dermis, loss of subcutaneous layer of fat, and los of collagen fibers. Turgor is lost. Some insulating function is lost with loss of subcutaneous fat. Dermal layer thins.

Define radiation, convection, evaporation, and conduction and give an example of each.

Radiation - The diffusion or dissemination of heat by electromagnetic waves. Example - The body gives off waves of heat from uncovered surfaces. Convection - The dissemination of heat by motion between areas of unequal intensity. Example - An oscillating fan blows currents of cool air across the surface of a warm body. Evaporation - The conversion of a liquid to a vapor. Example - Body fluid in the form of perspiration and insensible loss is vaporized from the skin. Conduction - The transfer of heat to another object during direct contact. Example - The body transfers heat to an ice pack, causing the ice to melt.

Describe the structures and main functions of the skin.

Skin structures - epidermis, dermis, hypodermis (subcutaneous). Functions of the integumentary system - protection, thermoregulation, metabolism, sensation, communication, storage.

Identify the structures and functions of a fingernail or toenail.

Structure - nail bed, nail body, nail plate, lunula, nail matrix, cuticle, nail groove, bone. Nails protect the sensitive tips of the fingers and toes. They help grab and pick up objects.

Compare and contrast the functions of the sudoriferous glands and the sebaceous glands.

Sudoriferous glands are sweat glands located in the dermis. Sebaceous glands are oil glands that lie close to the hair follicle into which they drain.

Explain the purpose of "goose bumps" or "goose flesh".

The skin conserves heat through shivering and "goose flesh" and gives off heat via the sweat glands.

Discuss the skin's role in sensory awareness.

The skin receives stimuli from the outside world, providing a dynamic interaction between external and internal environment protection. This is part of the skin's role in protection. Nerve endings in the dermis register pain and pleasure. The nerve receptors in the skin also sense hot and cold, vibration, and pressure, and provide these stimuli to the brain.