All of you know about the process of respiration which of the very important process in all living organism. During Respiration energy is produced in the body of an animals. In this article, we will discuss about the all about Human respiratory system that is - Respiratory system parts and functions, Types of Respiratory system etc.
Respiration is a process of gaseous exchange where oxygen is taken and carbon dioxide is released out as a result of oxidation. It is an essential and continuous process in which food is oxidized to release energy in the form of ATP (Adenosine Tri Phosphate) molecules.
Ingested food gets oxidized by oxygen taken in through the air. Carbon dioxide is eliminated and the energy that is released during oxidation is stored in the form of ATP molecules. In this process respiratory organs, blood and the body cells play an important role. Respiratory organs supply oxygen and remove water and carbon dioxide. Blood transports the gases from the respiratory organs to the tissue cells and vice versa. Cells of the body oxidize the food and produce energy.
The main human respiratory organs of include nostrils and nasal chamber, pharynx, larynx, trachea, bronchi, bronchioles, lungs and accessory respiratory organs such as diaphragm and inter-costal muscles.
Nostrils are the opening of the nose through which Oxygen rich air is taken inside the body and carbon dioxide rich air containing water vapour is expelled the body.
The space between the external and internal nares is known as nasal chamber. Each one internally is lined by a mucous membrane. It is divided into right and left parts by a cartilage known as mesethmoid. Each half of the nasal chamber is further divided into three regions:
This is the arteriormost part of the nasal chamber. It has hair to trap dust particles and prevent them from going inside.
This is the part richly supplied with capillaries, it warms the air and makes it moist.
This is lined by sensory epithelium for detection of smell.
Nasal chamber opens into the pharynx, which is a short, vertical tube measuring about 12 cm. in length. The respiratory and the food passages cross each other in the pharynx. Its upprt part is known as naso-pharynx and the lower part is called laryngo-pharynx.
In the pharynx there are tonsils which are made up of lymphatic tissue. They kill bacteria trapped in the mucous.
It is the sound producing organ. In males the larynx increases in size at the time of puberty. Hence, it is called Adam's apple and can be noticed in the neck region. From the pharynx air enters the larynx through an opening called glottis. The glottis is guarded by a flap called epiglottis.
It prevents the entry of food particles into the respiratory passage. Along the sides of the glottis are two folds of elastic tissue called vocal chords. These are responsible for producing sound.
It is also called as wind pipe. It is about 12cms long and 2.5cms wide. It lies in front of the oesophagus and extends downward into the neck. The wall of the trachea is made up of fibrous muscular tissue supported by 'C'-shaped cartilage rings. These are 16-20 in number. They make the trachea rigid. The trachea is internally lined with ciliated epithelium and mucous glands.
If any foreign particle enters, it is immediately expelled out by the mucus. By ciliary movement, they are swept towards the larynx and finally they enter the oesophagus.
The distal end of the trachea is divided into two bronchi behind the sternum. Each bronchus is supported by a complete ring of cartilage. It enters into the lung of its respective side. On entering the lung, each bronchus further divides into secondary and then tertiary bronchus.
Tertiary bronchi divide into many minutes bronchioles. Wall of each bronchiole does not have cartilage rings. Each bronchiole ends into a balloon-like alveolus. These alveoli make the lungs spongy and elastic.
These are the principal respiratory organs. Lungs are paired, hollow, elastic organs. The term respiration includes a complete process of taking in oxygen and giving out carbon dioxide. It includes breathing, external respiration, internal respiration and cellular respiration. They are located in the thoracic cavity. Each lung is enclosed in pleural sac. It is made up of two membranes, outer parietal and inner visceral. The enclosed cavity is called the pleural cavity. It is filled with a pleural fluid, which lubricates the pleura and prevents the friction when the pleural membranes slide over each other.
Lungs are pink in colour, soft, spongy and highly vascular (richly supplied with blood capillaries). The left lung is divided into two lobes. Each lobe consists of bronchioles which terminate in a bunch of spherical thin walled air sacs called alveolar sacs. Each sac has about twenty alveoli which look like grapes. They are covered with a network of capillaries from the pulmonary artery and vein. Alveoli have very thin highly elastic walls. Each alveolus is about 0.1mm in diameter. The human lung has about 750 million alveoli. The total area covered by them is about 50 times the surface area of skin. The large number of alveoli greatly increase the surface area for the exchange of gases.
The term respiration includes a complete process of taking in oxygen and giving out carbon dioxide. It includes breathing, external respiration, internal respiration and cellular respiration.
The process by which air comes in and goes out of the lungs is called breathing. It is any process that speeds up the rate of gaseous exchange.
The term respiration and breathing are not synonymous as breathing is a part of respiration. Breathing includes inspiration and expiration. During inspiration air containing more carbon dioxide and water vapour is forced out of the lungs.
Inspiration occurs in the following steps:
1. It is an active process. It is brought about by ribs, intercostal muscles sternum and diaphragm. The intercostal muscles contract, pulling the ribs outward and increase the space in the thoracic cavity. The lower part of the breast bone sternum is also raised.
2. The diaphragm contracts and becomes almost flat. Volume of the thoracic cavity is further increased.
3. Pressure on the lungs decrease. The lungs expand and their volume increases.
4. Atmospheric air rushes into the lungs through the respiratory passage to make the pressure eqaul. Thus the air enters the lungs.
1. It is a passive process. It takes place in the following steps:
2. The inter-costal muscles relax pulling the ribs inwards. This reduces the volume of the thoracic cavity.
3. The diaphragm relaxes and again becomes dome shaped. This reduces the volume of the thoracic cavity from the bottom.
4. The pressure on the lungs increases. The lungs get compressed and the air in the lungs, rushes out through the air passage.
Alternate inspiration and expiration together form the respiratory cycle. It occurs 16-20 times per minute in man. Breathing is under the control of the medulla oblongata of the brain.
The transport of respiratory (O2 and CO2) gases takes place in the following events-
1. External respiration
2. Internal respiration
3. Cellular respiration
The respiratory processes which take place in the lungs are included in external respiration. Oxygen is taken up by the blood in the lungs capillaries and carbon dioxide from the blood is released in the air in the lungs.
External respiration includes three events:
Concentration of oxygen is higher in the inspired air than in the alveolar blood and the concentration of carbon dioxide is higher in the alveolar blood than in the inspired air. This results in the exchange of oxygen from the air into the blood and carbon dioxide from blood into the air which is exhaled out.
The absorbed oxygen combines with the haemoglobin of RBCs. Haemoglobin is a respiratory protein pigment. It forms the unstable oxy-haemoglobin.
Hb (Haemoglobin) + O2 (Oxygen) = HbO2 (Oxy-haemoglobin)
Carbon dioxide from the blood is released in the air. CO2 is brought from the tissue cells by the blood in the form of sodium and potassium bicarbonates in the blood plasma. Some amount of CO2 is also brought by haemoglobin in the form of carbamino-haemoglobin. CO2 brought in all these forms is released.
The respiratory processes which take place in the tissue cells are included in internal respiration. Oxygen brought by the blood is given to the tissue cells and carbon dioxide from the tissues, is passed into the blood. When the blood reaches the tissue cells, the unstable oxy-haemoglobin breaks up to form haemoglobin and oxygen.
1. Carbon dioxide dissolves in the cellular fluid and passes into the plasma. CO2 dissolves in the water to form carbonic acid.
CO2 + H2O = H2CO3
Carbonic acid is converted into sodium and potassium bicarbonates.
About 80% to 85% carbon dioxide is carried by the blood in the form of bicarbonates.
2. A small amount of carbon dioxide combines with haemoglobin to form carbamino-haemoglobin.
3. Some carbon dioxide dissolves in the plasma and is carried to the lungs.
The ultimate purpose of respiration is to release energy. This is carried out in the cells by oxidation of food. This process is called as oxidative phosphorylation. It results in the formation of ATP molecules. Energy is stored in this form. This energy is used to carry out vital life processes.
Respiration is a process of gaseous exchange where oxygen is taken and carbon dioxide is released out as a result of oxidation. It is an essential and continuous process in which food is oxidized to release energy in the form of ATP (Adenosine Tri Phosphate) molecules.
Ingested food gets oxidized by oxygen taken in through the air. Carbon dioxide is eliminated and the energy that is released during oxidation is stored in the form of ATP molecules. In this process respiratory organs, blood and the body cells play an important role. Respiratory organs supply oxygen and remove water and carbon dioxide. Blood transports the gases from the respiratory organs to the tissue cells and vice versa. Cells of the body oxidize the food and produce energy.
Respiratory system parts and functions-
The main human respiratory organs of include nostrils and nasal chamber, pharynx, larynx, trachea, bronchi, bronchioles, lungs and accessory respiratory organs such as diaphragm and inter-costal muscles.
1. Nostrils and nasal chambers:
Nostrils are the opening of the nose through which Oxygen rich air is taken inside the body and carbon dioxide rich air containing water vapour is expelled the body.
The space between the external and internal nares is known as nasal chamber. Each one internally is lined by a mucous membrane. It is divided into right and left parts by a cartilage known as mesethmoid. Each half of the nasal chamber is further divided into three regions:
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| Respiratory system |
a) Vestibule:
This is the arteriormost part of the nasal chamber. It has hair to trap dust particles and prevent them from going inside.
b) Respiratory part:
This is the part richly supplied with capillaries, it warms the air and makes it moist.
c) Sensory part:
This is lined by sensory epithelium for detection of smell.
2) Pharynx:
Nasal chamber opens into the pharynx, which is a short, vertical tube measuring about 12 cm. in length. The respiratory and the food passages cross each other in the pharynx. Its upprt part is known as naso-pharynx and the lower part is called laryngo-pharynx.
In the pharynx there are tonsils which are made up of lymphatic tissue. They kill bacteria trapped in the mucous.
3) Larynx:
It is the sound producing organ. In males the larynx increases in size at the time of puberty. Hence, it is called Adam's apple and can be noticed in the neck region. From the pharynx air enters the larynx through an opening called glottis. The glottis is guarded by a flap called epiglottis.
It prevents the entry of food particles into the respiratory passage. Along the sides of the glottis are two folds of elastic tissue called vocal chords. These are responsible for producing sound.
4) Trachea:
It is also called as wind pipe. It is about 12cms long and 2.5cms wide. It lies in front of the oesophagus and extends downward into the neck. The wall of the trachea is made up of fibrous muscular tissue supported by 'C'-shaped cartilage rings. These are 16-20 in number. They make the trachea rigid. The trachea is internally lined with ciliated epithelium and mucous glands.
If any foreign particle enters, it is immediately expelled out by the mucus. By ciliary movement, they are swept towards the larynx and finally they enter the oesophagus.
5) Bronchi and bronchioles:
The distal end of the trachea is divided into two bronchi behind the sternum. Each bronchus is supported by a complete ring of cartilage. It enters into the lung of its respective side. On entering the lung, each bronchus further divides into secondary and then tertiary bronchus.
Tertiary bronchi divide into many minutes bronchioles. Wall of each bronchiole does not have cartilage rings. Each bronchiole ends into a balloon-like alveolus. These alveoli make the lungs spongy and elastic.
6) Lungs:
These are the principal respiratory organs. Lungs are paired, hollow, elastic organs. The term respiration includes a complete process of taking in oxygen and giving out carbon dioxide. It includes breathing, external respiration, internal respiration and cellular respiration. They are located in the thoracic cavity. Each lung is enclosed in pleural sac. It is made up of two membranes, outer parietal and inner visceral. The enclosed cavity is called the pleural cavity. It is filled with a pleural fluid, which lubricates the pleura and prevents the friction when the pleural membranes slide over each other.
Lungs are pink in colour, soft, spongy and highly vascular (richly supplied with blood capillaries). The left lung is divided into two lobes. Each lobe consists of bronchioles which terminate in a bunch of spherical thin walled air sacs called alveolar sacs. Each sac has about twenty alveoli which look like grapes. They are covered with a network of capillaries from the pulmonary artery and vein. Alveoli have very thin highly elastic walls. Each alveolus is about 0.1mm in diameter. The human lung has about 750 million alveoli. The total area covered by them is about 50 times the surface area of skin. The large number of alveoli greatly increase the surface area for the exchange of gases.
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| Alveoli |
Mechanism of Respiration:
The term respiration includes a complete process of taking in oxygen and giving out carbon dioxide. It includes breathing, external respiration, internal respiration and cellular respiration.
1.Breathing:
The process by which air comes in and goes out of the lungs is called breathing. It is any process that speeds up the rate of gaseous exchange.
The term respiration and breathing are not synonymous as breathing is a part of respiration. Breathing includes inspiration and expiration. During inspiration air containing more carbon dioxide and water vapour is forced out of the lungs.
a) Inspiration:
Inspiration occurs in the following steps:
1. It is an active process. It is brought about by ribs, intercostal muscles sternum and diaphragm. The intercostal muscles contract, pulling the ribs outward and increase the space in the thoracic cavity. The lower part of the breast bone sternum is also raised.
2. The diaphragm contracts and becomes almost flat. Volume of the thoracic cavity is further increased.
3. Pressure on the lungs decrease. The lungs expand and their volume increases.
4. Atmospheric air rushes into the lungs through the respiratory passage to make the pressure eqaul. Thus the air enters the lungs.
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| Inspiration & Expiration |
b) Expiration:
1. It is a passive process. It takes place in the following steps:
2. The inter-costal muscles relax pulling the ribs inwards. This reduces the volume of the thoracic cavity.
3. The diaphragm relaxes and again becomes dome shaped. This reduces the volume of the thoracic cavity from the bottom.
4. The pressure on the lungs increases. The lungs get compressed and the air in the lungs, rushes out through the air passage.
Alternate inspiration and expiration together form the respiratory cycle. It occurs 16-20 times per minute in man. Breathing is under the control of the medulla oblongata of the brain.
Transport of gases:
The transport of respiratory (O2 and CO2) gases takes place in the following events-
1. External respiration
2. Internal respiration
3. Cellular respiration
1. External respiration:
The respiratory processes which take place in the lungs are included in external respiration. Oxygen is taken up by the blood in the lungs capillaries and carbon dioxide from the blood is released in the air in the lungs.
External respiration includes three events:
A) Exchange of gases:
Concentration of oxygen is higher in the inspired air than in the alveolar blood and the concentration of carbon dioxide is higher in the alveolar blood than in the inspired air. This results in the exchange of oxygen from the air into the blood and carbon dioxide from blood into the air which is exhaled out.
B) Formation of oxy-haemoglobin:
The absorbed oxygen combines with the haemoglobin of RBCs. Haemoglobin is a respiratory protein pigment. It forms the unstable oxy-haemoglobin.
Hb (Haemoglobin) + O2 (Oxygen) = HbO2 (Oxy-haemoglobin)
C) Release of carbon dioxide:
Carbon dioxide from the blood is released in the air. CO2 is brought from the tissue cells by the blood in the form of sodium and potassium bicarbonates in the blood plasma. Some amount of CO2 is also brought by haemoglobin in the form of carbamino-haemoglobin. CO2 brought in all these forms is released.
2. Internal respiration:
The respiratory processes which take place in the tissue cells are included in internal respiration. Oxygen brought by the blood is given to the tissue cells and carbon dioxide from the tissues, is passed into the blood. When the blood reaches the tissue cells, the unstable oxy-haemoglobin breaks up to form haemoglobin and oxygen.
1. Carbon dioxide dissolves in the cellular fluid and passes into the plasma. CO2 dissolves in the water to form carbonic acid.
CO2 + H2O = H2CO3
Carbonic acid is converted into sodium and potassium bicarbonates.
About 80% to 85% carbon dioxide is carried by the blood in the form of bicarbonates.
2. A small amount of carbon dioxide combines with haemoglobin to form carbamino-haemoglobin.
3. Some carbon dioxide dissolves in the plasma and is carried to the lungs.
3. Cellular respiration:
The ultimate purpose of respiration is to release energy. This is carried out in the cells by oxidation of food. This process is called as oxidative phosphorylation. It results in the formation of ATP molecules. Energy is stored in this form. This energy is used to carry out vital life processes.
Cellular respiration takes place mainly in the mitochondria of cells. ATP is formed as the main product while by products are CO2 and water which are transported by the blood to the lungs. Energy released as heat is used to maintain the body temperature.
