1. Chapter 6 Body Systems
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2. 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
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3. 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
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4. 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
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5. 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
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6. 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
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7. 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
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8. 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
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9. Forensic Science II: Body Systems, Chapter 6
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10. Properties of Blood Red Blood Cells White Blood Cells Platelets Plasma
Forensic Science II: Body Systems, Chapter 6
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11. 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
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12. White Blood Cells Also called leukocytes
Protects the body against infection and fight viruses and bacteria.
Forensic Science II: Body Systems, Chapter 6
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13. 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
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14. 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
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15. Human Heart Atria—upper chamber Ventricles—lower chamber
Forensic Science II: Body Systems, Chapter 6
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16. 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
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17. 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
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18. 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
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19. Blood Splatters Forensic Science II: Body Systems, Chapter 6
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20. The Respiratory System (Obj 6.3, 6.4)
Forensic Science II: Body Systems, Chapter 6
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21. The Respiratory System—Structures
Forensic Science II: Body Systems, Chapter 6
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22. 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
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23. The Muscular System (Obj 6.5, 6.6)
Forensic Science II: Body Systems, Chapter 6
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24. 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
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25. The Forensic Implications of Other Body Systems (Obj 6.7)
Forensic Science II: Body Systems, Chapter 6
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26. The Forensic Implications of Other Body Systems
Forensic Science II: Body Systems, Chapter 6
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27. The Forensic Implications of Other Body Systems
Forensic Science II: Body Systems, Chapter 6
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28. The Forensic Implications of Other Body Systems
Forensic Science II: Body Systems, Chapter 6
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29. 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
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30. 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
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31. 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