Fundamentals of Anatomy & Physiology Eleventh Edition Chapter 5 The Integumentary System Lecture Presentation by Deborah A. Hutchinson Seattle University © 2018 Pearson Education, Inc.

© 2018 Pearson Education, Inc.

5-9 Repair of the Integument Repair of the integument following an injury Bleeding, swelling, and pain occur Mast cells trigger inflammatory response A scab (dried blood clot) stabilizes and protects the area Macrophages clean the area Fibroblasts and endothelial cells divide, producing granulation tissue © 2018 Pearson Education, Inc.

Figure 5–16 Repair of Injury to the Integument (Part 1 of 4). Inflammation Phase Bleeding occurs at the site of injury immediately after the injury, and mast cells in the region trigger an inflammatory response. Epidermis Dermis Mast cells © 2018 Pearson Education, Inc.

Figure 4–21 Inflammation and Regeneration (Part 3 of 5). Inflammation produces several familiar indications of injury. These indications are the so-called cardinal signs of inflammation: redness, heat (warmth), swelling, pain, and sometimes loss of function. Inflammation may also result from the presence of pathogens, such as harmful bacteria, within the tissues. The presence of these pathogens constitutes an infection. Increased Blood Flow Increased Vessel Permeability Pain In response to the released chemicals, blood vessels dilate, increasing blood flow through the damaged tissue. Vessel dilation is accompanied by an increase in the permeability of the capillary walls. Plasma now diffuses into the injured tissue, so the area becomes swollen. The abnormal conditions within the tissue and the chemicals released by mast cells stimulate nerve endings that produce the sensation of pain. PAIN Increased Local Temperature Increased Oxygen and Nutrients Increased Phagocytosis Removal of Toxins and Wastes The increased blood flow and permeability cause the tissue to become warm and red. Vessel dilation, increased blood flow, and increased vessel permeability result in enhanced delivery of oxygen and nutrients. Phagocytes in the tissue are activated, and they begin engulfing tissue debris and pathogens. Enhanced circulation carries away toxins and wastes, distributing them to the kidneys for excretion, or to the liver for inactivation. O2 Toxins and wastes © 2018 Pearson Education, Inc.

Figure 5–16 Repair of Injury to the Integument (Part 2 of 4). Migration Phase After several hours, a scab has formed and cells of the stratum basale are migrating along the edges of the wound. Phagocytic cells are removing debris, and more of these cells are arriving with the enhanced circulation in the area. Clotting around the edges of the affected area partially isolates the region. Migrating epithelial cells Macrophages and fibroblasts Granulation tissue © 2018 Pearson Education, Inc.

Figure 5–16 Repair of Injury to the Integument (Part 3 of 4). Proliferation Phase About a week after the injury, the scab has been undermined by epidermal cells migrating over the collagen fiber meshwork produced by fibroblast proliferation and activity. Phagocytic activity around the site has almost ended, and the fibrin clot is dissolving. Fibroblasts © 2018 Pearson Education, Inc.

Figure 5–16 Repair of Injury to the Integument (Part 4 of 4). Scarring Phase After several weeks, the scab has been shed, and the epidermis is complete. A shallow depression marks the injury site, but fibroblasts in the dermis continue to create scar tissue that will gradually elevate the overlying epidermis. Scar tissue © 2018 Pearson Education, Inc.

5-9 Repair of the Integument Repair of the integument following an injury Clot begins to dissolve Number of capillaries declines Non-cellular scar tissue is produced A raised keloid may form © 2018 Pearson Education, Inc.

Figure 5–17 A Keloid. © 2018 Pearson Education, Inc.

© 2018 Pearson Education, Inc.

Clinical Note 5-4 Burns and Grafts. Partial-Thickness Burns Full-Thickness Burns Erythema In a first-degree burn or partial- thickness burn, only the surface of the epidermis is damaged. In this type of burn, which includes most sunburns, the skin reddens and can be painful. The redness, a sign called erythema (er-i-THĒ-muh), results from inflammation of the sun-damaged tissues. In a second-degree burn or partial- thickness burn, the entire epidermis and perhaps some of the dermis are damaged. Hair follicles and glands are usually not affected, but blistering, pain, and swelling occur. If the blisters rupture, infection can easily develop. Healing typically takes one to two weeks, and some scar tissue may form. Third-degree burns, or full-thickness burns, destroy the epidermis and dermis, extending into the subcutaneous layer. Despite swelling, these burns are less painful than second-degree burns, because sensory nerves are destroyed. These burns cannot repair themselves, because granulation tissue cannot form and epithelial cells cannot cover the injury site. Skin grafting is usually necessary. © 2018 Pearson Education, Inc.

Clinical Note 5-4 Burns and Grafts (Part 1 of 4). Partial-Thickness Burns Erythema In a first-degree burn or partial- thickness burn, only the surface of the epidermis is damaged. In this type of burn, which includes most sunburns, the skin reddens and can be painful. The redness, a sign called erythema (er-i-THĒ-muh), results from inflammation of the sun-damaged tissues. © 2018 Pearson Education, Inc.

Superficial Partial Thickness

Clinical Note 5-4 Burns and Grafts (Part 2 of 4). Partial-Thickness Burns In a second-degree burn or partial- thickness burn, the entire epidermis and perhaps some of the dermis are damaged. Hair follicles and glands are usually not affected, but blistering, pain, and swelling occur. If the blisters rupture, infection can easily develop. Healing typically takes one to two weeks, and some scar tissue may form. © 2018 Pearson Education, Inc.

 

Deep Partial Thickness

Clinical Note 5-4 Burns and Grafts (Part 3 of 4). Full-Thickness Burns Third-degree burns, or full-thickness burns, destroy the epidermis and dermis, extending into the subcutaneous layer. Despite swelling, these burns are less painful than second- degree burns, because sensory nerves are destroyed. These burns cannot repair them- selves, because granulation tissue cannot form and epithelial cells cannot cover the injury site. Skin grafting is usually necessary. © 2018 Pearson Education, Inc.

 

Deep Full Thickness

Severity of Burn Injury   Superficial or First Degree – Epidermis – No Blisters 2. Partial Thickness or Second Degree – Deeper dermal layers – Blisters 3. Full Thickness or Third Degree – Full skin thickness – Charring 4. Full Thickness – Full thickness involving bones and muscles

What is the Rule of Nines?

Adult Rule of Nines 􀁺   Head and neck 9% 􀁺   Front torso 18% 􀁺   Back torso 18% 􀁺   Upper extremities 9% Each 􀁺   Lower extremities 18% Each 􀁺   Genitalia 1% 􀁺   Total 100%

Rule of Nines

Pediatric Rule of Nines 􀁺 Head and Neck 18% 􀁺 Front torso 18% 􀁺 Back torso 18% 􀁺 Upper Extremities 9% 􀁺 Lower Extremities13.5% each 􀁺 Genitalia 1% 􀁺 Total 100%