body systems. leann fletcher michael fletcher was in the bathroom when he heard the gunshot....

Body Systems

LEANN FLETCHER

• Michael Fletcher was in the bathroom when he heard the gunshot. Fletcher ran out of the bathroom and found his wife, Leann, face down in a pool of blood on their bedroom floor.

• Michael called 911 right away. When police and EMS arrived at the scene, Fletcher led them to the bedroom. A 45-caliber Smith and Wesson automatic pistol was lying next to Leann’s right hand.

• During an initial assessment of the scene and the victim, it appeared that she suffered from a gunshot wound to the head.

• The cerebral artery is the primary source of oxygen-rich blood to the brain. Even after the artery had been severed, the heart had continued to pump blood to the brain for several seconds.

• Because of this blood flow, very dark, thick blood surrounded the victim. Upon arrival, emergency medical personnel determined that the victim showed no sign of life.

• The crime-scene unit arrived at the scene. After photographing the body, the medical examiner covered the victim’s hands with bags to preserve trace evidence.

• Investigators collected and bagged the gun. The latent fingerprint expert dusted for fingerprints, and crime-scene investigators collected blood from the carpet.

• Gravity caused the blood to pool in the parts of Leann’s body that were touching the floor. Her thighs and face appeared bruised and bloated due to the pooling blood. Investigators estimated her time since death at just over an hour.

• Michael Fletcher was the only suspect in the case. Although he told the same story several times to several investigators, the investigators were “unsettled” by his statement. He said that he and his wife had just returned from the shooting range when he went into the bathroom.

• He had given the bullets to his wife to reload his gun. He said he heard the shot, ran out of the bathroom, and found his wife on the floor in a pool of blood.

• During the autopsy, the medical examiner performed a complete internal and external examination. Characteristics of the gunshot wound were consistent with being shot from 18 inches away. It would have been impossible for the victim to shoot herself from this distance.

• Michael Fletcher was arrested and charged with murder. A jury found him guilty of second degree murder. He was sentenced to life in prison. He is not eligible for parole until 2017.

INTRODUCTION• The study of the structure of the

human body is called anatomy. • The study of the function of the

body systems is physiology.• Anatomy and physiology are often

studied together because the structure of a cell or organ supports its function.

INTRODUCTION• Ex. The large surface area of a red

blood cell (RBC) allows the cell to absorb and release oxygen and carbon dioxide (Anatomy). The shape also allows the cells to be flexible as they move through the blood vessels, preventing clotting (Anatomy).

• RBC carry oxygen to all the cells of the body and return carbon dioxide to the lungs (Physiology).

• An understanding of anatomy and physiology is extremely important in forensic science.

• This knowledge allows scientists to interpret information about the crime from physical and biological evidence found at the crime scene.

• Your body systems work together to keep your body temperature, blood pH, and all other physical and chemical conditions relatively constant.

• This stable internal environment is called homeostasis.

THE CIRCULATORY SYSTEM

• Important in a death investigation.

• The major structures- heart, blood, arteries, and veins.

• The system is divided into two pathways— systemic circulation and pulmonary circulation.

Platelets• Helps for blood clots

when a blood vessel rips or tears.

• After the clot hardens, it becomes a scab.

• Certain medications and medical conditions affect the body’s normal blood-clotting mechanism.

• The oxygenated blood returns to the left atrium via the pulmonary vein.

• From the left atrium, blood flows into the left ventricle through the bicuspid valve.

• From that it travels to the aorta and then to the rest of the body.

• Blood travels away from the heart toward the rest of the body through arteries.

• Blood flows back to the heart through veins.

https://www.youtube.com/watch?v=BEWjOCVEN7M

Pathway of Blood through the Heart