Studyguide

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?

It is composed of the skin and its derivatives such as: hair, nails, and oil glands. It covers the entire body and accounts for about 7% of body weight. Pliable, yet durable, 1.5 to 4.0 mm thick, and composed of the epidermis and dermis.

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

FUNCTION |EXAMPLE | |

Protection |Chemical Barriers:

-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 prevents bacterial invasion

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

Biological Barriers:

-Langerhans’ cells in epidermis present antigens to lymphocytes

- Dermal macrophages– 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 |-Meissner’s corpuscle and Merkel cells – detect changes in pressure

-Pacinian receptors – detect deep pressure contacts

-Hair follicle receptors – movement across the surface of the skin

-Nerve endings – detect painful stimuli | |

Metabolic Functions |-Synthesis of Vitamin D – increases calcium absorption in the body

-Chemical conversion of many substances | |Blood Reservoir |vasoconstriction and vasodilation | |Excretion

|elimination of nitrogen-containing...