RBSE Class 11 Biology Notes Chapter 17 Breathing and Exchange of Gases

These comprehensive RBSE Class 11 Biology Notes Chapter 17 Breathing and Exchange of Gases will give a brief overview of all the concepts.

RBSE Class 11 Biology Chapter 17 Notes Breathing and Exchange of Gases

→ Respiration: All these process which are related to energy production by oxidation of food substances called respiration commonly.

→ Cells use oxygen for metabolic processes and along with energy various harmful substances like CO₂ are produced.

→ Respiratory, system: In human a well developed respiratory system is present which includes nose, nasal passage, pharynx, larynx, respiratory tract and lungs. Lungs are the primary respiratory organs which are situated on both sides of the mid line in the thorax.

→ The mechanism of respiration starts with breathing which involves movement of gases in between the external atmosphere and lungs. The gaseous transport from the external atmosphere to the lungs is called inspiration whereas the transport of gases from lungs to external atmosphere is called expiration.

→ The process of inspiration and expiration occurs as a result of increase and decrease in the volume of thoracic cavity respectively, brought about by the movements of ribs and the diaphragm.

→ The mechanism of breathing is controlled by the respiratory centres of the central nervous system which are situated in medulla oblongata and pons.

→ The exchange of O₂ and CO₂ between lung alveoli and blood capillary and between blood capillaries and tissues is done by simple diffusion.

→ The transport of oxygen from lungs to tissues is carried out by a respiratory pigment haemoglobin present in red blood corpuscles.

→ The transport of carbon dioxide from tissues to lungs takes place in mainly these forms. In the form of carbonic acid, Bicarbonate, carboxyhaemoglobin and carbaminoacids.

→ As a result of infection by a variety of bacteria, viruses and fungi and by the deposition of dust and other external substances in the respiratory organs, various types of respiratory disorders are caused in which chronic obstructive lung disease, bronchial asthma, pneumonia and tuberculosis are the main disorders.

→ Respiration: The process of releasing energy by oxidation of food in cells.

→ Breathing: Entry of O₂ into lungs and movement of CO₂ from lungs to external atmosphere.

→ Terbinal bones: Spiral bones present in nasal cavity. 

→ Larynx: Sound producing system.

→ Schneidarian membrane: Olfactory sensitive membrane present on nasal epithelium.

→ Diaphragm: Muscular plate between thoracic cavity and abdominal cavity.

→ Bronchioles: Small branches of bronchus.

→ inspiration: Movement of air from external atmosphere to the lungs.

→ Expiration: Movement of air from lungs to external atmosphere.

→ Haemoglobin: An iron containing respiratory pigment.

→ Bohr's effect: Reduce of affinity of haemoglobin to O₂ on increasing CO₂ concentration or decreasing pH in blood.

→ Chloride shift: Exchange of Cl^- and HCO₃ between plasma and RBCs.

→ Haldane's effect: Maximum elimination of CO₂ by joining of O₂ and Hb in alveolar blood.

→ Glycolysis: Conversion of glucose molecule into two molecules of pyruvic acid in absence of O₂ in cells.

→ Kreb's cycle: Complete oxidation of pyruvic molecules in the presence of O₂ in mitochondria.