Chapter 6 Body Systems © 2012 Cengage Learning. All Rights Reserved

Introduction—Objectives Discuss the structure and function of the circulatory system. Evaluate the forensic implications of the circulatory system. Discuss the structure and function of the respiratory system. Evaluate the forensic implications of the respiratory system. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Introduction—Objectives Discuss the structure and function of the muscular system. Evaluate the forensic implications of the muscular system. Identify body systems and discuss their forensic implications. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Introduction—Vocabulary asphyxiation - a condition in which the amount of oxygen available to the lungs decreases sharply while the level of other gases, especially carbon monoxide, increases erythrocyte - red blood cell homeostasis - an organism’s relatively stable internal conditions leukocyte - white blood cell Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Introduction—Vocabulary lividity - pooling of blood in the lowest portion of the body platelets - cell fragments that help form blood clots at wound sites; also called thrombocytes rigor mortis - the stiffening of the skeletal muscles after death suffocation - condition in which the amount of oxygen available to the lungs is quickly diminished Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Leann Fletcher Michael Fletcher heard a gun shot and found his wife on the floor in a pool of blood Lividity showed time of death to be just over an hour Gun shot wound indicated that gun was about 18 inches from body Michael was arrested, charged, and convicted of second-degree murder 6 Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Introduction Anatomy—the study of the structure of the human body Physiology—the study of the function of the body systems Homeostasis—a stable internal environment Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Circulatory System (Obj 6.1, 6.2) Systemic—the heart pumps oxygenated blood through arteries to body cells Pulmonary—the heart pumps the deoxygenated blood, carbon dioxide and other wastes to the lungs Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Properties of Blood Red Blood Cells White Blood Cells Platelets Plasma Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Red Blood Cells Also called erythrocytes Carries oxygen throughout the body Concave shape creates a large, efficient surface area Hemoglobin—a protein that binds oxygen for transport Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

White Blood Cells Also called leukocytes Protects the body against infection and fight viruses and bacteria. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Platelets Also called thrombocytes Helps form blood clots that act as a plug at open wounds These clots become scabs when hardened Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Plasma The liquid potion of blood—92% water Blood cells and platelets are suspended in plasma Transports important nutrients, vitamins and gases Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Human Heart Atria—upper chamber Ventricles—lower chamber Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Forensic Implications of the Circulatory System Blood type—class characteristic DNA—individual characteristic Blood—biological evidence Hemastix®—a presumptive test for blood Luminol—another presumptive test Collect samples of blood evidence Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Lividity Lividity—the pooling of blood in the direction of gravity Livor mortis— the change in color caused by lividity Bluish purple or reddish purple Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Petechiae Often occurs when a limb is in a hanging position Small red dots underneath the surface of the skin Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Blood Splatters Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Respiratory System (Obj 6.3, 6.4) Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Respiratory System—Structures Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Forensic Implications of the Respiratory System Cellular respiration 6O2 + C6H12O6  6CO2 + 6H2O + Energy C6H12O6 is glucose which comes from food Oxygen from the air combines with glucose to create energy for the cells in your body Asphyxiation—when the available oxygen decreases sharply while the level of toxic gases increases Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Muscular System (Obj 6.5, 6.6) Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Forensic Importance of the Muscular System Actin and myosin—two proteins that form fibers within muscles Muscles contract when myosin attaches to the actin, forming a bridge Lack of oxygen after death prevent muscles from relaxing Rigor mortis—the process in which the muscles of a body begin to stiffen Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Forensic Implications of Other Body Systems (Obj 6.7) Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Forensic Implications of Other Body Systems Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Forensic Implications of Other Body Systems Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

The Forensic Implications of Other Body Systems Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Each body system can offer clues regarding the events that led up to or occurred during the crime. The circulatory system systemic circulation pulmonary circulation The primary role of blood is to transport oxygen to the cells and wastes from them. Components are: red blood cells, white blood cells, platelets, and plasma. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Gas exchange occurs in the alveoli of the lungs. Capillaries, very small blood vessels surrounding the alveoli, transport oxygen into the body and carbon dioxide out of the body. Lividity occurs when blood pools in the lowest part of the body after a person dies. Lividity provides clues about the time and the position of the body at death. The primary function of the respiratory system is to remove gaseous wastes from the blood and to transport oxygen. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary The respiratory tract is divided into upper and lower. Asphyxia occurs when the amount of available oxygen decreases while toxic gases increase. Suffocation is a form of asphyxia that occurs when the amount of available oxygen decreases. Rigor mortis is the process where the muscles of the body begin to stiffen after death. Rigor begins within two hours after death and can last from 24 to 48 hours. Forensic Science II: Body Systems, Chapter 6 © 2012 Cengage Learning. All Rights Reserved