Vital Organs – Heart
The heart consists of four chambers:
- The atria: These are the two upper chambers, which receive blood.
- The ventricles: These are the two lower chambers, which discharge blood.
A wall of tissue called the septum separates the left and right atria and the left and right ventricle. Valves separate the atria from the ventricles.
The heart’s walls consist of three layers of tissue:
- Myocardium: This is the muscular tissue of the heart.
- Endocardium: This tissue lines the inside of the heart and protects the valves and chambers.
- Pericardium: This is a thin protective coating that surrounds the other parts.
- Epicardium: This protective layer consists mostly of connective tissue and forms the innermost layer of the pericardium.
If a person is stabbed in the heart between the ribs the heart can be penetrated. The heart is located between ribs number 2 and six on the left. Intercostal spaces have muscle layers between the ribs, so they can be penetrated by a knife or screwdriver or other instrument. Usually the right ventricle is hit with a stab wound as it sits more anteriorly, but deeper stabs can hit both ventricles. Left intercostal Interspaces 2,3,4,5 are the spaces between which a knife can be inserted and hit the heart. The ribs the bones can only protect if the path of the stabbing knife hits the rib itself, but because the heart is not encased fully by bone, the knife that is inserted between ribs 2–3 , 3–4, 4–5 can penetrate the heart is stabbing knife goes deep enough
A knife going deep 4.5 inches between the ribs can penetrate both the right ventricle and the left ventricle which is posterior.
A lateral or anterolateral stab can pass between the ribs and go straight to the heart, as can a vertical stab passing downward from just behind the clavicle or upward from below the ribcage. A sufficiently powerful stab using an ice pick or spike type of weapon, can break through the sternum and go directly to the heart from the front center of the chest.
This is how “Crocodile Hunter” Steve Irwin died. A very large stingray, startled and reacting to Irwin in the way it would defend itself from a shark, stabbed Irwin repeatedly in the chest. At least one stab went to the heart, presumably between his ribs, and caused massive cardiac damage.
Steve Irwin
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Filming on the fateful day
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