Exchange of Gases Alveoli are the primary sites of exchange of gases in the lungs. exchange of gases also occurs between blood and tissues. 

Respiratory Volumes & Capacities On an average, a healthy human breaths 12 - 16 Times/minute. the volume of the air involved in breathing movements, can be estimated b using a spirometer, which helps in clinical assessment of the pulmonary functions Click Here For complete lecture T.V = 6000 - 8000 ml/min IRV = 2500 - 3000 ml ERV = 1000 - 1100ml R.V = 1100 - 1200 ml IC = TV + IRV FRC = ERV+RV VC = TV+IRV+ERV TLC = VC + RV

Mechanism of Breathing Click Here for Complete Lecture breathing is a means of maximizing the process of gaseous exchange. the movement of air into and out of the lungs is carried out by creating a pressure gradient between the lungs and the atmosphere.    Inspiration:  intake of atmospheric air into the lungs is called inspiration. it is an active process. as it takes place by the contraction of the muscles of the diaphragm and the external inter costal muscles,  Expiration: release of alveolar air to the exterior is called expiration. it is passive process. relaxation of the diaphragm and the external inter costal muscles returns the diaphragm and sternum to their normal positions.

Breathing and Exchange of Gases   Pulmonary Tree Bronchi and Bronchioles:   On entering the mid thoracic cavity, treachea divides at the level of the 5th thoracic vertebra into right and left primary bronchi.. each primary bronchus enters the corresponding lung and divides into secondary bronchi that further divide into tertiary bronchi. Each tertiary bronchus divides and redivides to form primary, secondary, tertiary terminal and respiratory bronchiles sequentially. Each respiratory bronchile terminates in a cluster of alveolar ducts.  click here for complete lecture

Breathing and Exchange of Gases Larynx Anatomy Larynx is a cartilaginous box which helps in sound production, hence called the voice box. Wall of the larynx is supported by nine cartilages. Thyroid, cricoid and epiglottis are the unpaired cartilages, whereas coniculate cartilages, arytenoids and cuneiform cartilages are the paired cartilages. the mid ventral part of the thyroid cartilage forms the laryngeal prominence called adam's apple Click Here For Complete Lecture

Respiratory Organs Mechanisms of breathing vary among different groups of animals depending mainly on their habitats and levels of organisation. Protozoans and lower invertebrates such as the sponges, cnidarians, flatworms, etc., exchange with by simple diffusion over their entire body surface. Respiratory system of man includes the following :  1. External nostrils  2. Nasal Chambers  3. Naso-pharynx  4. Larynx  5. Trachea  6. Bronchi and Bronchioles the opening between the true vocal cords and the arytenoid cartilages is called rima glottidis. click here for complete lecture

MCQs from Digestive System You can click on below links for live quiz with NEET Bits 1 - 40 bits from Digestive System   41 - 80 bits from Digestive System

Digestion and absorption class 10 Calorific values of carbohydrates, proteins and fats:   T he oxidation of one gram of proteins and carbohydrates yield almost the same amount of energy i.e. 4.0 K cal. whereas it is 9.0 K cal in the case of fats. Disorders of the Digestive system:   T he inflammation of the intestinal tract is the most common ailment due to bacterial or viral infections. The infections are also caused by the parasites of the intestine such as tape worm, round worm, thread worm, hook worm, pin worm etc. Jaundice, Vomiting, Diarrhea, Constipation and Indigestion are some examples for digestion related disorders. Hyper acidity causes peptic ulcers in the wall of the stomach. However scientists found that peptic ulcers are caused by the bacterium Helicobacter Pylori.    Click here for complete lecture

 Digestion and absorption class 9 Absoption is the process by which the end products of digestion pass through the intestinal mucosa into blood or lymph. it is carried out by passive active of facilitated transport mechanisms.  absorption of substances takes place in different parts of the gut, like mouth, stomach, small intestine and large intestine. how ever maximum absorption of the end products of digestion occurs in the small intestine. Click here for complete Video