The Heart Essay Example
The heart is an organ that facilitates the supply of oxygen and blood to all parts of the body. It pumps deoxygenated blood to the lungs oxygenated blood to various parts of the body. The heart is allocated into four key chambers which are named according to where they are located. The upper two chambers are known as the right and the left atrium (Scott & Fong 2009).while the two lower chambers are referred to as the left and the right ventricle. Separating the left chambers of the heart from the right ones is a thick wall called the septum.
The atria receive blood from different sources of the body. For instance, the right atrium receives deoxygenated blood from the rest o the body while the left atrium receives oxygenated blood from the lungs ( BOSTWICK TAYLOR, P., & WINGERD, B. D. (2013). The human body, concepts of anatomy and physiology, 3rd edition, Bruce Wingerd. Philadelphia, Pa, Lippincott Williams & Wilkins.Top of Form
Wright 2000).The ventricles push blood to various parts of the body. The right ventricle push deoxygenated blood to the lungs whereas the left ventricle pumps oxygenated blood to various parts of the body. This task of pumping blood to the other parts of the body is enhanced by the thick walls of the ventricles which are thicker than those of the atria.
The Structure of the Wall
The walls of each of the four chambers of the heart consist of the following layers; epicardium, myocardium and endocardium. Epicardium, also known as viscreral pericardium, is the superficial layer of the heart covered by special connective tissues called mesothelium. The deeper part of this layer consists of adipose tissue. The function of this layer is to protect the inner layers.
Myocardium, derived from the word ‘myo’ meaning muscle, is the middle layer and it consists mainly of the cardiac muscles, which are responsible for heartbeat. These muscles are arranged in planes separated by connective tissues which are abundantly supplied with lymph capillaries, blood capillaries and nerve fibres. This layer is thin in both the right and the left atrium, but very thick in ventricles. The myocardium layer is three times thicker in the left ventricle than in the right ventricle. This is in order to contain the high pressure that is required to push oxygenated blood to the furthest parts of the body. In the atria it is less thick since the blood that flows in from other parts of the body has less pressure as compared to the blood that flows out. In the right ventricle there are conical projections known as papillary muscles. There three types of papillary muscles namely; anterior, posterior and septal. At the tips of the papillary muscle are tough and thin tendons called chordae, which connects papillary muscles to the free edges of valve cusps. They also prevent the cusps from being pushed into the atria, during the contraction of the ventricle.
Endocardium is the inner most layer of the wall which is exposed to blood. The inner surface of the endocardium layer consists of epithelium and connective tissues. These tissues comprise of collagenous and elastic fibres whose main function is to align the valves, the chambers of the heart as well as the blood vessels (Bostwick & Wingerd2013). The connective tissues line the purkinje fibres which enhan BOSTWICK TAYLOR, P., & WINGERD, B. D. (2013). The human body, concepts of anatomy and physiology, 3rd edition, Bruce Wingerd. Philadelphia, Pa, Lippincott Williams & Wilkins.Top of Form
ce the conduction system of the heart. In the right atrium, the endocardium layer is partly smooth and partly rough, whereby the rough portion consist of ear-like projection that contains pectinate muscles while the smooth portion receives the opening of the inferior and superior venacava and the coronary sinus.
. Philadelphia, Pa, Lippincott Williams & Wilkins.Top of FormThe human body, concepts of anatomy and physiology, 3rd edition, Bruce WingerdBOSTWICK TAYLOR, P., & WINGERD, B. D. (2013).
Bostwick Taylor, P., &Wingerd, B. D. (2013).The human body, concepts of anatomy and physiology, 3rd edition, Bruce Wingerd.Philadelphia, Pa, Lippincott Williams & Wilkins.
Scott, A. S., & Fong, E. (2009).Body structures & functions.Clifton Park, N.Y., Delmar.
Wright, D. B. (2000).Human physiology and health. Oxford, Heinemann.
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