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Here is a term paper on the ‘Process of Respiration’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short term papers on the ‘Process of Respiration’ especially written for school and college students.
Process of Respiration
Term Paper # 1. Breathing or Ventilation:
Ventilation is the exchange of air between the lungs and the atmosphere, so that oxygen can be exchanged for carbon dioxide in the alveoli (the tiny air sacs in the lungs).
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Air always moves from high pressure area to low pressure area. The atmospheric pressure (760 mmHg at sea level) is higher than the pressure inside the lungs. The body changes the pressure of the alveoli by changing the volume of the lungs. As the volume increases, pressure inside the lungs decreases and thus the air flows into the lungs.
Breathing is followed by a gaseous exchange between the blood and body tissues where carbon dioxide is produced in various metabolic activities, and oxygen is used. The blood takes oxygen from lungs and carries it to tissues that have a lower concentration of oxygen and a higher concentration of carbon dioxide.
Due to the difference in concentration, exchange of gases takes place between blood and tissues. This is called tissue respiration. It is followed by the last step in which food is oxidized inside the cells in mitochondria and energy is released. This is called cellular respiration.
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Capacities of the Lungs:
In normal breathing, a person takes approximately 500ml air, and this is known as tidal volume. The rate of respiration can be expressed in terms of ventilation rate i.e. the volume of air breathed per minute.
Rate of ventilation = Tidal volume × Frequency of inspiration.
The rate of ventilation changes during the heavy work or exercise. If a person first inspires with his/her utmost effort and then also expires with maximum effort, the volume of air breathed out is called the vital capacity. In an adult, it is about 500ml.
It is higher in athletes and mountain dwellers. A person cannot expel all the air present in the respiratory system. It is called the residual air. With effort, a person can inspire 3000ml of air in addition to the tidal volume. This additional volume of air that can be breathed in with maximum forceful inspiration is called the Inspiratory Reserve Volume (IRV).
Similarly, after breathing out the tidal volume, a person can expire an additional volume of about 1000ml air by maximum effort. This additional volume is called the Expiratory Reserve Volume (ERV).
Effect of Altitude on Breathing:
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As we go higher on a mountain above 800 feet from sea level, the air we breathe-in decreases in pressure along with in oxygen. As a result certain symptoms like headache, breathlessness, dizziness, vomiting loss of hearing and lack of muscular coordination develop. This is known as mountain sickness. The fall of oxygen level in the blood produces the symptoms of mountain sickness.
i. Inspiration:
Inspiration is also called as inhalation (breathing in). During inspiration, the intercostal muscles contract, the diaphragm descends, and the rib cage rises. The thoracic cavity volume increases, stretching the lungs, and the intrapulmonary volume increases. This causes the intrapulmonary pressure to drop. Air flows into the lungs until the intrapulmonary pressure equals the atmospheric pressure.
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ii. Expiration:
During expiration, which is also called as exhalation (breathing out), the intercostal muscles relax, the diaphragm rises, and the rib cage descends. The volume of thoracic cavity decreases causing the lungs to recoil.
The intrapulmonary volume decreases. This causes the intrapulmonary pressure to rise, and the air flows out of the lungs until the intrapulmonary pressure equals the atmospheric pressure.
Term Paper # 2. External Respiration:
The normal rate of respiration is 10-20 breaths per minute. In external respiration, exchange of gases occurs between the air present in the alveoli and the blood within the pulmonary capillary.
Term Paper # 3. Internal Respiration:
The exchange of gases between the body spaces or fluids and the cells is called internal respiration or tissue respiration. The area over which this exchange takes place is called the respiratory surface. The respiratory pigment, haemoglobin, absorbs oxygen from the lungs and carries it to tissues all over the body.
Term Paper # 4. Cellular Respiration:
Respiration is the process of releasing energy from the breakdown of glucose. Respiration takes place in every living cell, all the time. All the cells respire in order to produce the energy that they require.
Uses of Energy:
The energy produced during respiration is used in many different ways, some examples of what it is used for are:
1. Working your muscles
2. Growing and repairing of cells
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3. Building larger molecules from smaller ones i.e. proteins from amino acids
4. Allowing chemical reactions to take place
5. Absorbing molecules in active transport
6. Keeping body temperature constant
7. Sending messages along nerves.
