Respiratory system

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The respiratory system is a group of organs and tissues responsible for the inhalation of oxygen and exhalation of carbon dioxide, allowing the body to maintain proper oxygen and carbon dioxide levels. This system plays a crucial role in respiration, which is the process of exchanging gases between the body and the environment.

Main components of the respiratory system:

1. Nose and nasal cavity: The nasal cavity is the initial passage for air entering the respiratory system. It filters, warms, and humidifies the air before it moves to the next stage.
2. Pharynx: Also known as the throat, the pharynx is a muscular tube that connects the nasal cavity and mouth to the larynx and esophagus. It serves as a passageway for both air and food.
3. Larynx: The larynx, or voice box, is located at the top of the trachea. It contains the vocal cords and is responsible for producing sound. The larynx also helps prevent food from entering the trachea.
4. Trachea: The trachea, also known as the windpipe, is a tube that connects the larynx to the bronchi. It serves as the main passageway for air to reach the lungs.
5. Bronchi and bronchioles: The bronchi are two main branches that split from the trachea, entering the lungs. They further divide into smaller branches called bronchioles.
6. Alveoli: These tiny air sacs are found at the end of the bronchioles. They are the site of gas exchange between the air we breathe and our bloodstream. Oxygen from inhaled air diffuses into the capillaries, while carbon dioxide diffuses from the blood into the alveoli to be exhaled.
7. Lungs: The lungs are the primary organs of the respiratory system. They contain the bronchi, bronchioles, and alveoli, and are responsible for gas exchange.
8. Diaphragm: The diaphragm is a dome-shaped muscle located at the base of the lungs. It contracts and relaxes with each breath, allowing the lungs to expand and deflate.

Respiration process:

1. Inhalation: During inhalation, the diaphragm and intercostal muscles (located between the ribs) contract, causing the chest cavity to expand. This expansion leads to a decrease in pressure within the chest cavity, allowing air to flow into the lungs.
2. Gas exchange: In the alveoli, oxygen from the inhaled air diffuses across the thin alveolar walls into the capillaries. At the same time, carbon dioxide diffuses from the blood into the alveoli.
3. Exhalation: During exhalation, the diaphragm and intercostal muscles relax, causing the chest cavity to contract. This contraction increases the pressure within the chest cavity, forcing air out of the lungs.

In summary, the respiratory system allows for the exchange of gases between the body and the environment, helping to maintain proper oxygen and carbon dioxide levels in the body. This process is essential for cellular respiration, which generates the energy needed for cells to function.

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Transcript:-
Respiration is a process of exchange of gases between an organism and its environment. The exchange involves intake of oxygen and the elimination of carbon dioxide. Three types of respiration are recognized, and these include external, internal, and cellular respiration. The external respiration involves the passage of oxygen from the air into the alveoli of the lungs, and then into the.

Internal respiration involves the passage of oxygen from the blood into the tissues. Cellular respiration is also called biological oxidation. During this stage, oxygen is given to the cells by blood, and in turn, blood receives carbon dioxide from the cell. Respiration includes breathing or ventilation involving inspiration and expiration.

During inspiration, oxygen is taken to the lungs, which subsequently diffuses into the blood During expiration, carbon dioxide given up by the venous blood in the lungs is released into the atmosphere. The exchange of gases that take place in the lungs is known as pulmonary respiration. The lungs communicate with the external environment by a network of tubular passages, which may be divided into two parts, one, conducting part, and two respiratory part.

The conducting part consists of nasal cavity, pharynx, larynx, voice box trachea. Windpipe two primary bronchi, secondary, tertiary, and terminal bronchials in the lungs. The respiratory part consists of a pair of lungs, which contain respiratory, bronchials, alveolar ducts, alveolar sacs, and alveoli. The conducting portion of the respiratory system consisting of a series of interconnecting cavities and tubes, both outside and within the lungs, to provide a root for the air to reach the lungs while conditioning it by filtering, warming, or cooling and moistening air while conducting it into the lungs.

Nasal. The two nasal cavities open to the exterior by external nostrils. The nasal chamber is lined with affiliated columnar epithelium, which is dotted with muco cells that secrete mucus pharynx. It is a common passage of the respiratory and digestive systems. The pharynx has three parts, an anterior nasopharynx, middle oropharynx, and a posterior laryngopharynx.

Larynx or voice box. The pharynx opens into the larynx and irregular tube through the opening called glottis. The larynx controls the air pathway and is called the voice box because the true vocal chords which produce sound are located inside the larynx. Trachea or windpipe. It is a cylindrical tube about 12 centimeters long, extending from the larynx to the bifurcation of the two primary bronchi.

It is lined with respiratory epithelium and strengthened by 16 to 20 rings of hylan cartilage that are connected by dense fibroelastic ligaments. Bronchi. The trachea divides into two tubes called bronchi, and each bronchus enters the lung at the highland. Bronchials. Each primary bronchus divides into smaller secondary bronchi that are three in the right lung and two in the left lung.

The secondary bronchi further subdivide to give rise to tertiary bronchi and terminal bronchials with diameter less than one millimeter. The respiratory portion is the site of oxygen and carbon dioxide gas exchange. It consists of two lungs, the right and the left, and their functional units that include the alveolar ducts, alveolar sacs, and alveoli.

The lungs are spongy and protected in the thoracic cavity. The right lung is slightly larger than the left lung and is divided into three lobes, superior or upper, middle and inferior lobe. The left lung is divided into two lobes, the upper and inferior lobes. Each lung is covered by two membranes pleura.

The inner pulmonary or visceral pleura enveloping the lung and the outer parietal pleura. In closing the lung. The two membranes are separated by the plural cavity containing a thin film of fluid called plural fluid, which serves as a lubricant. The lungs are composed of bronchi, bronchials, alveolar ducts, alveolar sacs, and alveoli.

The branching airways bronchials at their end present with alveolar duct. The alveolar ducts are short tubes, which at their end open into atria or alveolar sacs. Each alveolar sac contains numerous thin walled compartments called alveoli or air sacs, which form the final elements of the bronchial tree that are surrounded by a rich network of capillaries.

The lung has many millions of alveoli, which give the lungs an incredible surface area for gas exchange. Each alves is hexagonal with pores on one side that help to equalize air pressure in the adjacent alveoli. The process of breathing or ventilation involves inspiration and expiration, which together constitute pulmonary respiration and a short pause.

Respiration is an automatic and involuntary process by which the expansion and contraction of lungs follow one after the other for inspiration and exploration to take place. Contraction of external intercostal muscles that is the muscles present between the ribs, increases the volume of the thorax laterally and dorsally.

Contraction of the diaphragm increases the size of the thoracic cavity from the anterior to the posterior side. As a result of these contractions, there is an increase in the volume of the thoracic cavity and consequently the lungs. Air from outside rushes in to fill the lungs, and inspiration is thus accomplished.

Relaxation of the external intercostal muscles and the diaphragm decreases the volume of thoracic cavity, which returns to its normal size. As a result, the lungs also come back to their normal size, and the air from the lungs is squeezed out, resulting in expiration. This is followed by a short pause.

Decrease in thoracic volume is accelerated by the contraction of abdominal muscles and also the internal intercostal muscles, which helps in vigorous expiration. Regular respiration is linked to cellular respiration.

Cellular respiration is a complimentary process that occurs along, along with the external respiratory process for the release of energy stored in the chemical bonds of glucose. The inhaled oxygen is transported to the cells of the body through the blood, and is utilized by the cells during a series of biochemical reactions for the production of the high energy molecule called adenosine triphosphate or a t p.

This process has three main stages, namely glycolysis, the citric acid, or Krebs cycle and electron transport chain. E TC with oxidative phosphorylation. Glycolysis occurs in the cellular cytoplasm through several steps of phosphorylation wherein glucose is first oxidized to release energy and water. Pyruvic acid produced during glycolysis enters the mitochondrion to be converted to acetyl coenzyme, a acetyl co a. Thereafter, the processes of Krebs cycle and electron transport and oxidative phosphorylation of the cellular respiration take place in the mitochondria.

During Krebs cycle, the acetyl coa produced after glycolysis is further converted into a T p and the two electron carrier molecules, namely N A D H, nicotinamide, adenine, dinucleotide, and. F A D H two Flavin, adenine, dinucleotide, which carry electrons to the electron transport system and are themselves oxidized to produce a t p. During E TC hydrogen ions are pumped into the inter-membrane space of the mitochondrion and the oxygen undergoes oxidative phosphorylation through an electron transport chain that contains a sequence of protein complexes embedded in the mitochondrial membrane.

The electrons derived from the cellular metabolism are transferred through these complex. This process requires oxygen to maintain the hydrogen ion gradient across the membrane, which results in a T P formation. The presence of oxygen increases the yield of a T P molecules 36 a T p, during aerobic respiration as against two ATP in the absence of oxygen.

Carbon dioxide released as a byproduct during this metabolism is then transported back to the lungs to become part of the external respiratory process once again. During respiration gas exchange is carried out by the small alveolar sacs that take up most of the space and the lungs inhaled oxygen, enters the air sacs, and then passes through the thin walls of the alveoli to the red blood cells in the surrounding capillaries.

This way, oxygen of the air is transferred to the blood and carbon dioxide from the blood is returned to the alveoli to be released from the lungs during expiration. Respiration, the process that involves the respiratory organs. Carrying out the process of gaseous exchange with a singular objective of sustaining life as represented through these animated videos helps in the effortless understanding of this crucial system that helps nourish life in the human body.