Breathing-and-Exchange-of-Gases.pdf

Breathing and Exchange of Gases © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Breathing and cellular respiration Types of cellular respiration Human respiratory system Conducting and respiratory parts Process of exchange of gases in body Location of the lungs © 2022, Aakash BYJU'S. All ri...

Breathing and Exchange of Gases © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Breathing and cellular respiration Types of cellular respiration Human respiratory system Conducting and respiratory parts Process of exchange of gases in body Location of the lungs © 2022, Aakash BYJU'S. All rights reserved. 1 2 3 Mechanism of gaseous exchange in invertebrates Mechanism of breathing 4 Inspiration and expiration Lung volumes and capacities External respiration Internal respiration Transportation of gases in blood Respiratory disorders 5 6 Summary​ © 2022, Aakash BYJU'S. All rights reserved. Artificial respiration Breathing and Cellular Respiration Breathing Cellular respiration Oxygen is inhaled and carbon dioxide is exhaled out of the lungs Breakdown of food using oxygen to produce energy which is used by cells to carry out cellular function No energy is produced during the process Energy is released in the form of ATP Takes place in respiratory organs Takes place in cells Physical process Biochemical process © 2022, Aakash BYJU'S. All rights reserved. Types of Cellular Respiration Types of cellular respiration Aerobic respiration Anaerobic respiration In the case of aerobic respiration, the oxygen inhaled during breathing is utilised for the breakdown of food, while the carbon dioxide that is generated is exhaled during breathing. In the case of anaerobic respiration, the breakdown of food occurs in the absence of oxygen, and lactic acid or ethanol is produced. © 2022, Aakash BYJU'S. All rights reserved. Mechanism of Gaseous Exchange in Various Organisms  Sponges, coelenterates, flatworms etc. rely on the movement of water through them for gaseous exchange.  Gills are special vascularised structures used by most aquatic arthropods, molluscs and fishes for breathing.  Earthworms breathe through their moist cuticle.   Insects use a network of tracheal tubes to transport air throughout the body. Most terrestrial organisms such as reptiles, birds and mammals have lungs for gaseous exchange.  Amphibians can respire through their moist skin as well besides using lungs. E.g. – frog. © 2022, Aakash BYJU'S. All rights reserved. Human Respiratory System Pathway of oxygen Pathway of carbon dioxide Nose Nasal cavity Nasopharynx Larynx Epiglottis Trachea Bronchus Terminal bronchioles Diaphragm © 2022, Aakash BYJU'S. All rights reserved. Human Respiratory System © 2022, Aakash BYJU'S. All rights reserved.  Nasal passage Air enters the respiratory system through the nostrils.  Nasal cavity It then travels through the nasal passage. o The nasal passage is separated into two chambers by the nasal septum. o It is lined with hair, which filters the dust particles present in the air.  Presence of rich vascular supply allows the nose to change the temperature and the humidity of the inspired air. Nasopharynx  It helps to keep the air entering the nose from drying out the lungs and other parts of our respiratory system.  The nasal cavity is at the farther end of the nasal passage.  It leads to the nasopharynx. Human Respiratory System Trachea/ Windpipe    Bronchi   Bronchiole  Alveoli     © 2022, Aakash BYJU'S. All rights reserved. It is a straight tube extending up to the mid-thoracic cavity. It is surrounded by incomplete cartilaginous rings that provide support to the trachea and prevent it from collapsing. At its farther end, it divides into left and right bronchi, which are referred to as the primary bronchi. Bronchi divide into numerous branches, which again sub-divide further into bronchioles. These are the passages that carry the inhaled air from the trachea to the bronchioles. Bronchioles carry air to the millions of alveoli present in the lungs. Bronchioles eventually terminate into alveoli. Alveoli are small sac-like structures that swell when air enters them. Alveoli are in close contact with the blood capillaries. Hence, alveoli are sites where the gaseous exchange between blood and lungs occurs. Conducting and Respiratory Parts The human respiratory system can be divided into a conducting part and a respiratory part.  Conducting part o It extends from the external nostrils up to the bronchioles. o It conducts air in and out of the lungs. o It clears the air of foreign particles. o It humidifies the air and brings it to the body temperature before it reaches the lungs.  Respiratory part/ Exchange part o It includes alveoli and its ducts. o It is involved in the exchange of gases between the lungs and blood. © 2022, Aakash BYJU'S. All rights reserved. Trachea Primary bronchi Conducting system Smaller bronchi Bronchioles Exchange surface Alveoli Process of Exchange of Gases in Body  Alveoli Veins bring carbon dioxide-rich blood from all over the body to the heart. o This carbon dioxide is released during the process of cellular respiration. C6H12O6 Heart Systemic veins Tissue © 2022, Aakash BYJU'S. All rights reserved. Glucose + 6O2 Oxygen 6CO2 Carbon dioxide + 6H2O Water Energy + stored in ATP  The heart then pumps this CO2-rich blood to the capillaries, surrounding the alveoli.  The gaseous exchange occurs between the capillaries and the alveoli, where CO2 diffuses into the alveoli, and O2 from the alveoli diffuses into the capillaries. Process of Exchange of Gases in Body Flow of freshly oxygenated blood Flow of oxygendepleted blood A capillary network covers the surface of the alveolus to facilitate the exchange of oxygen and carbon dioxide. © 2022, Aakash BYJU'S. All rights reserved.  Now, the oxygen-rich blood from the capillaries is carried to the heart, which pumps it throughout the body via arteries.  Meanwhile, the CO2-rich air is exhaled by the lungs.  Now, the cells of the body utilise the supplied oxygen to generate energy and release CO2 in the process.  Meanwhile, the lungs inhale the O2rich air and the cycle repeats itself. Location of the Lungs Pleural cavity Pericardial cavity Diaphragm Abdominal cavity Pelvic cavity © 2022, Aakash BYJU'S. All rights reserved. Thoracic cavity  Lungs are located in the pleural cavity inside the thoracic cavity.  Lungs are surrounded by double layered pleural membranes.  The thoracic cavity is covered in the following ways: o Dorsally by the vertebral column o Ventrally by the sternum o Laterally by the ribs o On the lower side by the domeshaped diaphragm  Any change in the volume of the thoracic cavity reflects in the volume of the lungs. Abdominopelvic cavity Mechanism of Breathing    Breathing is a physical process that takes place in the lungs. It involves the inspiration of oxygen and the expiration of carbon dioxide. It does not release energy. Inspiration Muscle that contracts Diaphragm External intercostals © 2022, Aakash BYJU'S. All rights reserved. Consequence Direction of expansion of thoracic cavity Diaphragm pulled down Anteroposterior (up-down) direction Rib cage expands upwards and outwards Dorsoventral (front-back) direction Mechanism of Breathing Inspiration Air inhaled Diaphragm contracts and moves downwards and external intercostal muscles contract and move the ribs upward and outward Chest expands Anteroposterior axis The intrapulmonary volume increases and pressure decreases This creates low pressure inside lungs © 2022, Aakash BYJU'S. All rights reserved. Air moves from outside to inside bringing about inhalation Mechanism of Breathing Expiration Muscle involved (quiet expiration) Consequence Direction of contraction of thoracic cavity Diaphragm Relaxation Diaphragm pulled up Antero-posterior (up-down) direction Rib cage comes back downwards and inwards Dorsoventral (front-back) direction External intercostals relaxation © 2022, Aakash BYJU'S. All rights reserved. Mechanism of Breathing Expiration Air exhaled Chest contracts Diaphragm relaxes Dorsoventral axis © 2022, Aakash BYJU'S. All rights reserved. While breathing out, the diaphragm relaxes and the volume of the thoracic cavity decreases in the longitudinal direction.  Decreased thoracic volume reduces the pulmonary volume  Intrapulmonary pressure increases Lung Volumes and Capacities Lung volume Lung volumes and capacities measure the following:  Amount of air that lungs can hold.  Measure of the amount of air breathed in and out. © 2022, Aakash BYJU'S. All rights reserved. Definition Value (ml) Tidal Volume (TV) It is the volume of air inspired or expired during normal respiration. 500 Inspiratory Reserve Volume (IRV) It is the additional volume of air that can be breathed in by forcible inspiration. 2,500-3,000 Expiratory Reserve Volume (ERV) It is the additional volume of air that can be breathed out by forcible expiration. 1,000-1,100 Residual Volume (RV) It is the volume of air left in lungs after forcible expiration. 1,100-1,200 Lung Capacities Lung capacity Definition Formula Value/breath (ml) Inspiratory Capacity (IC) It is the maximum volume of air that can be inspired after normal expiration. IC = TV + IRV 500 + 2,750 = 3,250 Functional Residual Capacity (FRC) It is the volume of air that remains in lungs after normal expiration. FRC = ERV + RV 1,050 + 1,150 = 2,200 Vital Capacity (VC) It is the maximum volume of air that can be inspired after forced expiration. VC = ERV + TV + IRV 1,050 + 500 + 2,750 = 4,300 Total Lung Capacity (TLC) It is the maximum volume of air in lungs after forced inspiration. TLC = RV + ERV + TV + IRV 1,150 + 1,050 + 500 + 2,750 TLC = RV + VC = 1,150 + 4,300 = 5,450 © 2022, Aakash BYJU'S. All rights reserved. Lung Volumes and Capacities Graphical representation Inspiratory Capacity (IC) Inspiratory Reserve Volume (IRV) Vital Capacity (VC) Tidal Volume (TV) Functional Residual Capacity (FRC) © 2022, Aakash BYJU'S. All rights reserved. Expiratory Reserve Volume (ERV) Residual Volume (RV) Total Lung Capacity (TLC) Lung Volumes and Capacities Spirometer  Some of these volumes and capacities can be measured by an instrument known as a spirometer.  It is useful in diagnosis of the following diseases: ○ Asthma ○ Shortness of breath ○ Assessing the effect of contaminants on lung infection ○ Effect of medication ○ Evaluating progress for disease treatment © 2022, Aakash BYJU'S. All rights reserved. Spirometer Alveoli  Alveoli are the primary sites of exchange of gases.  They are tiny air sacs located at the distal end of the bronchial tree.  They are thin-walled, moist, and richly supplied with blood capillaries.  The moistness helps in the dissolution of the gases and facilitates easy exchange of the gases. Gases move across the alveolar membrane through diffusion. © 2022, Aakash BYJU'S. All rights reserved. Alveoli From pulmonary artery Capillary Fluid Layer Alveolar membrane Respiratory membrane Air CO2 O2 Respiratory membrane (Diffusion membrane) © 2022, Aakash BYJU'S. All rights reserved.  The surface of the exchange of gases is known as respiratory membrane (diffusion membrane).  The alveolar wall and the capillary wall, along with their basement membranes, form the respiratory membrane.  The gases have to cross this membrane in order to enter into the bloodstream in the blood capillaries. External Respiration   Exchange of air that takes place between the blood capillaries and alveoli. Diffusion of O2 occurs from alveoli to the blood due to partial pressure difference. Oxygenated blood (pO2 = 95 mm Hg) Deoxygenated blood (pO2 = 40 mm Hg) Alveoli pO2 = 104 mm Hg O2 in © 2022, Aakash BYJU'S. All rights reserved. Factors Affecting the Rate of Diffusion Solubility of gases Factors affecting the rate of diffusion Partial pressure Diameter of the respiratory membrane Diffusion of gases across the alveolar membrane © 2022, Aakash BYJU'S. All rights reserved. Factors Affecting the Rate of Diffusion Solubility of gases Partial pressure © 2022, Aakash BYJU'S. All rights reserved.  A gas having a high solubility diffuses at a faster rate than a gas having a lower solubility.  The solubility of CO2 is 20–25 times higher than that of O2.  Partial pressure is the pressure contributed by an individual gas in a mixture of gases if it occupies the same volume on its own.  pO2- partial pressure of oxygen  pCO2- partial pressure of carbon dioxide  A gas always moves from a region of high partial pressure to a region of lower partial pressure. Factors Affecting the Rate of Diffusion Diameter of the respiratory membrane Diffusion of gases across the alveolar membrane © 2022, Aakash BYJU'S. All rights reserved.  The thinner the membrane involved in diffusion, the faster is the diffusion of gases.  The total thickness of the respiratory membrane is less than a millimetre.  The pO2 is higher in the alveoli than the deoxygenated blood.  So, there is diffusion of O2 from alveoli to the blood.  This turns the deoxygenated blood to oxygenated blood.  The blood that has higher concentration of oxygen is known as oxygenated blood.  The capillaries bring the deoxygenated blood to lungs, which has low oxygen concentration.  Due to this low concentration of oxygen, the partial pressure of oxygen within the capillaries will also be low. Internal Respiration Alveolar air pO2 = 104mm Hg Exchange of gases occurs between the blood and the tissues.  The pO2 of oxygenated blood is 95 mm Hg same as what it was when it left the lungs.  Now the pO2 of the tissues is much lower at 40 mmHg. So, the oxygen diffuses from the blood to the tissues.  The O2 is consumed and CO2 is released out from the tissues.  The pCO2 is higher in the tissues compared to the oxygenated blood so, the CO2 moves from tissues to the blood. Alveolus Pulmonary artery Pulmonary vein Systemic vein pO2 = 40 mm Hg Systemic artery pO2 = 95 mm Hg O2 © 2022, Aakash BYJU'S. All rights reserved.  Internal Respiration Alveolus Alveolar air pCO2 = 40 mm Hg  The carbon dioxide diffuses from the blood to the alveoli via external respiration. Systemic artery (carrying oxygenated blood from heart to tissues) Systemic vein (carrying deoxygenated blood from tissues to heart)  The addition of carbon dioxide along with the removal of oxygen makes the blood deoxygenated. So, the pCO2 changes from 40 to 45 mm Hg in the blood. Pulmonary vein Pulmonary artery pCO2 = 45 mm Hg  O2 pCO2 = 40 mm Hg The pCO2 of deoxygenated blood is 45 same as what it was when it left the tissues. © 2022, Aakash BYJU'S. All rights reserved. Transportation of Gases in Blood Transport of gases Oxygen Carbon dioxide Oxyhaemoglobin Carbaminohaemoglobin Dissolved form Dissolved form Dissolved form (3%) Carbamino haemoglobin (23%) Haemoglobin (97%) Bicarbonates (70%) © 2022, Aakash BYJU'S. All rights reserved. Bicarbonates Dissolved form (7%) Transport of Oxygen Dissolved form  Oxygen is dissolved in the blood plasma.  The blood plasma, a component of blood, can also dissolve oxygen in it.  However, oxygen is not very soluble in blood, so only 3% of oxygen is transported in the dissolved form. Oxyhaemoglobin  Since the majority of oxygen cannot be transported in the dissolved form, our bodies have evolved another system to transport oxygen. i.e. as oxyhaemoglobin.  The red blood cells have a respiratory pigment, that is, haemoglobin.  Haemoglobin comprises globin and haem.  Globin is the protein molecule and haem is the red pigment that gives blood its red colour.  There are four protein chains and four haems.  Each haem has an iron atom at its centre. © 2022, Aakash BYJU'S. All rights reserved. Transport of Oxygen Oxyhaemoglobin  Haemoglobin has an affinity for oxygen.  It carries four molecules of oxygen.  The haem part of haemoglobin combines reversibly with oxygen to form oxyhaemoglobin.  Oxyhaemoglobin formation takes place in the alveoli.  In tissues, this reverses and the oxyhaemoglobin releases oxygen. Hb Free haemoglobin © 2022, Aakash BYJU'S. All rights reserved. + O2 In alveoli HbO2 In tissues Oxygen Oxyhaemoglobin Transport of Carbon Dioxide Carbaminohaemoglobin      Just like oxygen, four CO2 molecules can bind to the Hb molecule. However, they do not bind to the iron atom. Instead, they bind to the amine groups on the protein chains. The haemoglobin picks up CO2 from the cells and transports it as carbaminohaemglobin all the way from the tissues to the alveoli, which is an unstable molecule. CO2 is dropped at the alveoli, and O2 is picked up from the alveoli. © 2022, Aakash BYJU'S. All rights reserved. CO2 CO2 𝝱 chain 1 𝝱 chain 2 CO2 Heme CO2 Fe2+ 𝛂 chain 2 𝛂 chain 1 Hb + Free haemoglobin CO2 In tissues In alveoli Carbon dioxide HbCO2 Carbaminohaemoglobin Transport of Carbon Dioxide Dissolved form   The solubility of CO2 is 20–25 times higher than that of O2. Therefore, 7% of carbon dioxide dissolves in the blood plasma and is transported to the lungs. Bicarbonates      The largest fraction of carbon dioxide is converted into bicarbonate ions. When carbon dioxide diffuses into RBCs at the tissues, it combines with water, forming carbonic acid. Since carbonic acid is unstable, it quickly dissociates into bicarbonate ions and hydrogen ions. Although, this reaction also occurs in plasma, it is a thousand times faster in RBCs because they contain the enzyme, carbonic anhydrase. This enzyme reversibly catalyses the conversion of carbon dioxide and water to carbonic acid. © 2022, Aakash BYJU'S. All rights reserved. The ratio of amount of oxygen combined with haemoglobin to the amount of oxygen that haemoglobin is capable of carrying gives the percentage saturation of haemoglobin.  The saturation percentage and the partial pressure of oxygen are represented in the form of a curve known as the oxygen-haemoglobin dissociation curve.  It is also known as the oxygen dissociation curve, and is sigmoid or Sshaped. © 2022, Aakash BYJU'S. All rights reserved. Volumes (%)  Haemoglobin saturation (%) Saturation of Haemoglobin Pressure of oxygen in blood (PO2) (mm Hg) Factors Affecting Oxygen-Haemoglobin Dissociation Curve In alveoli: ○ There is high pO2, low pCO2, less H+, and less temperature. ○ This favours oxyhaemoglobin association.  In tissues: o There is low pO2, high pCO2, high H+, and high temperature which favours the dissociation of O2 from oxyhaemoglobin. o As the partial pressure of oxygen increases, the affinity of Hb for O2 also increases. © 2022, Aakash BYJU'S. All rights reserved. Volumes (%)  Haemoglobin saturation (%) pO2, pCO2, H+ concentration and temperature Pressure of oxygen in blood (PO2) (mm Hg) Factors Affecting Oxygen-Haemoglobin Dissociation Curve CO2 concentration When there is increase in CO2 concentration in blood CO2 + H2O H2CO3 H+ + HCO3- Increased carbon dioxide in blood reacts with water to form carbonic acid, giving more hydrogen and bicarbonate ions. Higher H+ lowers the blood pH High H+ ions lower the blood pH and induces oxyhaemoglobin to give up more oxygen to the cells easily. O2 - Hb dissociation curve shifts right © 2022, Aakash BYJU'S. All rights reserved. Artificial Respiration It is a technique of artificially stimulating the natural functioning of the respiratory system when a person stops breathing because of drowning, electric shocks, accident, gas poisoning, anaesthesia etc. Artificial respiration Manual method Mechanical method Ventilator Clearing the airways via mouth to mouth and compression CPR - Cardiopulmonary resuscitation © 2022, Aakash BYJU'S. All rights reserved. Use of instruments to help breathe like tracheostomy tube, iron lung, ventilator Mechanical Method Mechanical method can be defined as the technique through which breathing and respiration is performed with the help of an external device connected directly to the patient. Ventilator  It is the most common method.  Various machines are used to help the patient breathe.  Patients breathing through a ventilator are said to be on life support. © 2022, Aakash BYJU'S. All rights reserved. Iron lung  It is an enclosure used to change the pressure in the space to make the person breathe. Tracheostomy tube  Involves insertion of a special tube by making a cut in the neck to facilitate the entry of air into the lungs. Regulation of Breathing Regulation of breathing Neural regulation Chemical regulation There are two sites of neural regulation. There are two areas of chemical regulation. Respiratory centres Areas Medullary respiratory centres © 2022, Aakash BYJU'S. All rights reserved. Pons respiratory centres Chemosensitive area adjacent to rhythm center Carotid bodies and aortic bodies Respiratory Centres for Neural Regulation Respiratory centres Medullary respiratory centres Respiratory rhythm centre Pons respiratory centres Pneumotaxic centre Apneustic centre Inspiratory group Pons respiratory centre Expiratory group  Inspiratory group - Stimulates the respiratory muscles to contract during inspiration  The pneumotaxic center, located in the upper pons, sends signals to stop inspiration by inhibiting the apneustic center.  Expiratory groups - Stimulates muscles for expiration  It limits tidal volume.  The apneustic and pneumotaxic center work against each other together to control the respiratory rate. © 2022, Aakash BYJU'S. All rights reserved. Respiratory Centres for Chemical Regulation Rhythm centres Normal concentration of CO2 and H+ ions Concentration of CO2 and H+ ions alters Medulla senses pH changes Activates rhythm centre Rhythm centre sends necessary signals to alter respiratory rate © 2022, Aakash BYJU'S. All rights reserved. Carotid body and aortic body sense changes Hering-Breuer Reflex Arch  This reflex prevents the alveoli from bursting. Medullary respiratory centres Activates stretch receptors in terminal bronchioles  This prevents alveoli from overstretching or bursting. Activates Hering-Breuer Reflex arch  Hence, this is called a protective reflex. Switches off inspiration © 2022, Aakash BYJU'S. All rights reserved. Respiratory Disorders Mountain sickness  Occurs due to hypoxia at high altitudes o Hypoxia = Shortage of oxygen o Occurs due to the presence of thin air at high altitudes  Symptoms: o Vomiting o Breathlessness o Headache o Disorientation o Fatigue o Irritability © 2022, Aakash BYJU'S. All rights reserved. Respiratory Disorders Bronchial asthma  It is a chronic medical condition which results in the swelling of the airway path of the lungs which, as a result, becomes narrow.  Due to this swelling, the air path produces excess mucus making it hard to breathe.  It is caused by mould, dust mites, fragrance, cigarette smoke, cleaning chemicals, pets etc.  Symptoms: o Coughing o Wheezing o Difficulty in breathing © 2022, Aakash BYJU'S. All rights reserved. Tight muscles Excess mucus Clogged airway Asthmatic bronchiole Respiratory Disorders Pulmonary Tuberculosis     It is caused by Mycobacterium tuberculosis. It is an airborne disease and spreads by inhalation. It results in destruction of lung tissue which then gets replaced by fibrous connective tissue. Symptoms: o Coughing and chest pain o Loss of appetite o Chills and fever o Night sweats o Fatigue Emphysema      © 2022, Aakash BYJU'S. All rights reserved. Emphysema means shortness of breath. It is caused by smoking and inhalation of toxic gases and smoke. This condition results in o Loss of elasticity in lungs as elastic tissue is replaced by connective tissue. o Alveoli becoming weak and their walls break down. o As a result, lungs remain inflated, and expiration becomes difficult. Symptoms: o Inflammation of bronchioles and alveoli o Expiration becomes difficult Preventive measures: o No smoking o Use pollution masks Respiratory Disorders Occupational respiratory disorders  It is any lung condition that arises due to the role of the person at the workplace.  It occurs because of repeated exposure to certain toxins over a period of time such as gas fumes, dust, silica and asbestos.   Often seen in individuals working in mining, stone grinding and stone breaking industries. It results in o Fibrosis of upper lung and inflammation due to the damage to lung tissue. The lung tissue becomes scarred, thickened and stiff, making it difficult for the lungs to work properly.  Symptoms: o Difficulty in breathing  Protection masks can help in keeping the workers safe. © 2022, Aakash BYJU'S. All rights reserved. Summary Mechanism of gaseous exchange In invertebrates Porifera Annelida Platyhelminthes Water current entering through ostia Diffusion through cuticles Arthropods Spiracles and tracheoles Aquatic arthropods Book gills Fishes Gill slits Amphibians Skin, lungs and bucco-pharynx Birds Air sacs © 2022, Aakash BYJU'S. All rights reserved. Summary Human respiratory system Nose Nasal cavity Nasopharynx Larynx Epiglottis Trachea Bronchus Terminal bronchioles Alveoli Diaphragm © 2022, Aakash BYJU'S. All rights reserved. Summary Inspiration Anteroposterior axis Air inhaled Air exhaled Chest expands Chest contracts Diaphragm contracts Dorsoventral axis © 2022, Aakash BYJU'S. All rights reserved. Expiration Anteroposterior axis Diaphragm relaxes Dorsoventral axis Summary Graphical representations of lung capacities Inspiratory Capacity (IC) Inspiratory Reserve Volume (IRV) Vital Capacity (VC) Tidal Volume (TV) Functional Residual Capacity (FRC) © 2022, Aakash BYJU'S. All rights reserved. Expiratory Reserve Volume (ERV) Residual Volume (RV) Total Lung Capacity (TLC) Summary Exchange of gases Alveoli (External respiration) CO2 O2 External respiration: It is the exchange of air that takes place between the blood capillaries and the alveoli. Transport of gases CO2 O2 Tissues (Internal respiration) © 2022, Aakash BYJU'S. All rights reserved. Internal respiration: It is the exchange of air that takes place between the blood and the tissues. Summary Artificial respiration Artificial respiration involves induction of breathing by some manipulative technique when natural respiration has ceased or is faltering. Manual method The manual methods include clearing the airways via mouth to mouth and CPR. Mechanical method Mechanical method can be defined as the technique through which breathing, and respiration are performed with the help of an external device connected directly to the patient. Ventilator Iron lung Tracheostomy tube © 2022, Aakash BYJU'S. All rights reserved. Summary Respiratory disorders Mountain sickness Bronchial asthma Emphysema © 2022, Aakash BYJU'S. All rights reserved. Pneumonia Pulmonary tuberculosis Occupational respiratory diseases Hiccup SARS Snoring