How is the mammalian heart adapted to its functions? - KCSE Biology Essay

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Heart is enclosed in a pericardial membrane/pericardium; that produces a fluid; to lubricate it; the membrane also keeps the heart in position;

It is covered in a fatty layer; that acts as a shock absorber;

Made up of cardiac muscles; which are interconnected/interacted hence contract and relax without fatigue or nervous stimulation/myogenic; for continuous pumping of blood
throughout the lifespan of the animal;

The muscles are supplied by nutrients and oxygen; by the coronary arteries; and the coronary veins take away wastes and carbon (IV) oxide;

Heart is divided into 4 chambers; for efficient double circulation/ avoid mixing of oxygenated and deoxygenated blood/carry large volume of blood;

Has interventricular septum; to separate oxygenated and deoxygenated blood;

Ventricles are thick/muscular; to generate high pressure to pump blood out of the heart;

Left ventricle has thick muscles/more muscular; to pump blood to all body tissues;

Heart has bicuspid; and tricuspid valves; to prevent back flow of blood to left auricle; and right auricle respectively;

Valves have tendinous cords/valve tendons; to prevent them from turning inside out;

Semi lunar valves located at the beginning of major arteries; prevent backflow of blood into the ventricles;

Has sino-artrio node located in the muscles of the right auricle; to initiate heart beat/contractions of heart muscles/cardiac muscles, rate of heart beat is controlled by nerves; vagus nerve; slows down heartbeat; while sympathetic nerve; speeds up the heartbeat;

Has aorta; to transport oxygenated blood to all body parts;

Has pulmonary artery; that transports deoxygenated blood from right ventricles to lungs for oxygenation;

Has pulmonary vein; that transports oxygenated blood from lungs to the left ventricles; for distribution to all body parts;

Has the venacava; that receives deoxygenated blood from all body parts to right ventricles;


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Read 26517 times Last modified on Friday, 07 December 2018 09:37
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