Cells, Tissues, Organs and Organ Systems - Literature review Example

Cells, Tissues, Organs and Organ systems. of Cells, Tissues, Organ and Organ system Living organisms are collections of small parts called cells. Cells aggregate together to form a tissue and more than one tissue constitute an organ while many organs combine to form an organ system. The combination of the above parts forms the organism and enables it to perform its life processes. The differences between a cell, tissue, organ and an organ system are highlighted in the table below. Animal cell Blood tissue Heart (organ) Circulatory system(organ system) A cell is made up of particular organelles. A tissue constitutes many cells. The heart organ is composed of many tissues. It is a collection different organs. A cell is found in both unicellular and multicellular organisms. A tissue is found in multicellular organisms only. An organ is found in multicellular organisms with a collection of tissues. An organ system is also found in multicellular organisms. An organ system depicts a higher organization of life. A cell has an enclosing bag called the cell membrane. A tissue has no defined outer covering. The tissues in an organ work towards achieving an individual task. The bodies in an organ system are made up of multiple tissues that drive on a life process. A cell has one nucleus hence carry limited genetic material in them. Tissues are multinucleate since they have many cells. Organs have more nuclei in their structure hence have more genetic material in them. The organs forming it have many cells hence many nuclei in them thus carrying more genetic material than the organs. Cells, tissues, organs and organ systems differ in many ways. The composition of each of the above differentiates them. A cell is a smaller unit of life which is made up of different organelles that perform various functions in the cell. A tissue is a collection of cells which may have the same structure to perform a particular function. An organ consists of different tissues that work together to perform a function. An organ system is a higher unit of life which coordinates various organs to drive an important life process. The structure and appearance of the cell and the tissue can be used to differentiate the two. A cell is seen to have a defined outer cover called the plasma membrane. On the other hand, a tissue, organ and organ system have no defined outer covering layers. (Starr et al. 2013). The Circulatory system is an example of an organ system and includes different organs such as the heart, and lungs. A heart is an organ that differs from the circulatory system by being a smaller unit of the larger circulatory system. Blood tissue is formed by many cells of different structure. These cells include the white blood cells, red blood cells and platelets. These cells are differentiated to perform specific functions. is an organ which has tissues such as the cardiac muscle, connective tissue, nervous tissue all which work together to accomplish the task of pumping the blood. (Starr et al. 2013). The Functions of the cardiovascular and respiratory system. The Cardiovascular system is made up of the blood vessels and the heart. (Rosdahl & Kowalski 2008 ). There are two main types of blood vessels namely; veins and arteries. Veins carry deoxygenated blood under low pressure, except the pulmonary vein. The arteries carry blood under high pressure hence has thick muscles and a narrow lumen to sustain the pressure of the blood. The role of the heart is to propel the blood containing oxygen to different parts of the body and also receive blood deficient of oxygen from different parts of the body. The heart is a muscular organ with myogenic muscles that contract and relax continuously throughout the life of an organism. The heart is surrounded by pericardium layer that protects it. The heart is fractioned into left and right sides by a muscular wall called septum. Blood in the two sides does not mix. The interior of the heart is subdivided into four portions called chambers. The upper chambers are known as auricles while the lower chambers are called ventricles. Auricles receive blood entering the heart while the ventricles pump blood out of the heart. The right auricle receives deoxygenated blood from the body through the vena cava. The left atrium receives blood rich in oxygen from the lungs through the pulmonary vein. The right ventricle receives blood from the right auricle through the opening of the tricuspid valve and pumps it to the lungs for oxygenation. (Fritch & Kuhnel 2008). The left ventricle receives oxygenated blood from left auricle through the opening of the bicuspid valve and pumps it to the entire body parts. The left ventricle has thicker muscles since it pumps blood to the furthest part of the body. The function of the cardiovascular system is to pump oxygenated blood from the lungs to the body parts and deoxygenated blood from the body parts to the lungs for oxygenation. Blood carries the nutrients dissolved in the plasma and on reaching the target body cells, the nutrients diffuse into the cells to aid in growth and development of the organism. Blood vessels provide pathways through which blood is transported. Blood from the body tissues is rich in carbon IV oxide from cellular respiration. When this blood reaches the lungs, it drops carbon IV oxide and picks up oxygen from the lungs. The Respiratory system consists of the lungs, muscles that help in breathing and the airways through which air passes to reach the lungs. Lungs are found in the ribcage that is hard and firm to protect the lungs from mechanical damage. (Burstein 2009). The lung is consists of numerous alveoli. These are the sites for gaseous exchange. (Chihas 2011). The alveoli are highly supplied with numerous blood capillaries that collect oxygen from inhaled air and release carbon iv oxide during exhalation. Human beings have a pair of lungs namely; right and left lungs. Each lung is by a sac membrane called the pleural membrane. (Herman 2007). The pleural membrane produces pleural fluid that reduces friction between the lungs and the thoracic cavity during breathing in and out. Another part found in the thoracic cavity is the diaphragm. It is elastic and muscular in nature to expand and contract. During inspiration, the diaphragm flattens and moves downwards. This increases the volume of the thoracic cavity and reduces the pressure inside the thorax. Air gets in and moves to the lungs where oxygen diffuses to the capillaries in the body. The diaphragm also curves upwards when it relaxes to reduce the volume of the thoracic cavity during exhalation. This leads to increased pressure in the thorax, making air rich in carbon dioxide to be exhaled from the body. (Herman 2007). The primary task of the respiratory system is to supply oxygen to the body and take away carbon IV oxide from the body to outside. Air from the atmosphere enters the through the nostrils and runs down to the lungs through the trachea, bronchus and the bronchioles to the lungs. The trachea and the bronchi warm and moisten the air and transport it to the lungs. The bronchioles transport air to the alveoli where oxygen diffuses into the blood vessels during inhalation and carbon dioxide diffuse from the blood vessels to the outside during exhalation. (BURSTEIN. 2009) Respiration system supplies air to the body while the cardiovascular system transports the gases in the body through the blood as the transport media. From the above descriptions of the two systems, it is clear that the two systems depend on each other to accomplish their functions. During the gaseous exchange, the circulatory system through the heart pumps blood to the lungs where there is the exchange of gases. The circulatory system distributes blood rich in oxygen and nutrients to the body cells. It also transports carbon dioxide to the lungs for exhalation from the body. Oxygen is carried in the blood by the red blood cells using a respiratory fluid called hemoglobin. Haemoglobin binds with oxygen to form oxyhaemoglobin in which it is channeled to the body cells. Oxygen is needed in the cells to perform aerobic respiration to yield the energy required to drive the life processes. Carbon dioxide from aerobic respiration in the body is exhaled because it is toxic to the body. It dissolves in the blood plasma to form weak carbonic acid in which it is carried by the cardiovascular system. On reaching the lungs, it the carbonic acid dissociates and releases carbon dioxide for exhalation. ( Mcardle, Katch & Katch 2010) BIBLIOGRAPHY Fritsch, H., & Kũhnel, W. (2008). Color atlas of human anatomy. Volume 2, Volume 2. Stuttgart, Thieme. Chiras, D. D. (2005). Human biology. Boston, Jones and Bartlett Publishers. Herman, I. P. (2007). Physics of the human body. Berlin, Springer. Burstein, J. (2009). The remarkable respiratory system: how do my lungs work? New York, NY, Crabtree Pub. Rosdahl, L, C. B., & Kowalski, M. T. (2008). Textbook of basic nursing. Baltimore, MD, Lippincott Williams & Wilkins. Starr, C., Taggart, R., Evers, C. A., & Starr, L. (2013). Biology: the unity & diversity of life. [Pacific Grove, Calif.?], Brooks/Cole Cengage Learning. Mcardle, W. D., Katch, F. I., & Katch, V. L. (2010). Exercise physiology: nutrition, energy, and human performance. Baltimore, MD, Lippincott Williams & Wilkins. Read More