The lungs are the primary organs of the respiratory system in humans and many other animals including a few fish and some snails. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart, their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals and birds use their different muscles to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm; the lungs provide airflow that makes vocal sounds including human speech possible. Humans have a right lung and a left lung, they are situated within the thoracic cavity of the chest. The right lung is bigger than the left.

The lungs together weigh 1.3 kilograms, the right is heavier. The lungs are part of the lower respiratory tract that begins at the trachea and branches into the bronchi and bronchioles, which receive air breathed in via the conducting zone; the conducting zone ends at the terminal bronchioles. These divide into the respiratory bronchioles of the respiratory zone which divide into alveolar ducts that give rise to the alveolar sacs that contain the alveoli, where gas exchange takes place. Alveoli are sparsely present on the walls of the respiratory bronchioles and alveolar ducts. Together, the lungs contain 2,400 kilometres of airways and 300 to 500 million alveoli; each lung is enclosed within a pleural sac that contains pleural fluid, which allows the inner and outer walls to slide over each other whilst breathing takes place, without much friction. This sac divides each lung into sections called lobes; the right lung has three lobes and the left has two. The lobes are further divided into pulmonary lobules.

The lungs have a unique blood supply, receiving deoxygenated blood from the heart in the pulmonary circulation for the purposes of receiving oxygen and releasing carbon dioxide, a separate supply of oxygenated blood to the tissue of the lungs, in the bronchial circulation. The tissue of the lungs can be affected by a number of respiratory diseases, including pneumonia and lung cancer. Chronic obstructive pulmonary disease includes chronic bronchitis and emphysema, can be related to smoking or exposure to harmful substances. A number of occupational lung diseases can be caused by substances such as coal dust, asbestos fibres, crystalline silica dust. Diseases such as bronchitis can affect the respiratory tract. Medical terms related to the lung begin with pulmo-, from the Latin pulmonarius as in pulmonology, or with pneumo- as in pneumonia. In embryonic development, the lungs begin to develop as an outpouching of the foregut, a tube which goes on to form the upper part of the digestive system.

When the lungs are formed the fetus is held in the fluid-filled amniotic sac and so they do not function to breathe. Blood is diverted from the lungs through the ductus arteriosus. At birth however, air begins to pass through the lungs, the diversionary duct closes, so that the lungs can begin to respire; the lungs only develop in early childhood. The lungs are located in the chest on either side of the heart in the rib cage, they are conical in shape with a narrow rounded apex at the top, a broad concave base that rests on the convex surface of the diaphragm. The apex of the lung extends into the root of the neck, reaching shortly above the level of the sternal end of the first rib; the lungs stretch from close to the backbone in the rib cage to the front of the chest and downwards from the lower part of the trachea to the diaphragm. The left lung shares space with the heart, has an indentation in its border called the cardiac notch of the left lung to accommodate this; the front and outer sides of the lungs face the ribs, which make light indentations on their surfaces.

The medial surfaces of the lungs face towards the centre of the chest, lie against the heart, great vessels, the carina where the trachea divides into the two main bronchi. The cardiac impression is an indentation formed on the surfaces of the lungs where they rest against the heart. Both lungs have a central recession called the hilum at the root of the lung, where the blood vessels and airways pass into the lungs. There are bronchopulmonary lymph nodes on the hilum; the lungs are surrounded by the pulmonary pleurae. The pleurae are two serous membranes. Between the pleurae is a potential space called the pleural cavity containing a thin layer of lubricating pleural fluid; each lung is divided into lobes by the infoldings of the pleura as fissures. The fissures are double folds of pleura that help in their expansion; the main or primary bronchi enter the lungs at the hilum and branch into secondary bronchi known as lobar bronchi that supply air to each lobe of the lung. The lobar bronchi branch into tertiary bronchi known as segmental bronchi and these supply air to the further divisions of the lobes known as bronchopulmonary segments.

Each bronchopulmonary segment has arterial supply. Segments for the left and right lung are shown in the table; the segmental anatomy is useful clinically for localising disease processe

Marjorie Keller

Marjorie Keller was an experimental filmmaker, activist, film scholar, wife of P. Adams Sitney, the American avant-garde cinema historian. J. Hoberman called her "an unselfish champion of the avant-garde." Keller was born in 1950 in New York. The youngest of seven children, Keller grew up in a upper-middle-class, Protestant family; as a girl, Keller's mother schooled her in the feminine arts of cooking and entertaining. Keller never gave up these skills though other feminists of her time frowned upon such domestic jobs. B. Ruby Rich, fondly remembers a Passover dinner that Keller made in this passage from her memoir: "And the food was great, because Margie was a fabulous cook: for a rebel girl of that era, she was remarkably versed in the female arts." Keller first attended Tufts University, but finished her coursework at the School of the Art Institute of Chicago after getting expelled from Tufts for participating in a protest in 1972. She went on to pursue her master's degree and her doctorate in Cinema Studies at New York University in 1975.

During her years at Tufts and the Art Institute of Chicago, Keller was instructed by American avant-garde filmmakers Saul Levine and Stan Brakhage. Marjorie Keller was entrenched in the politics of her generation, she was arrested for participating in a protest at the White House against Nixon's price control policies, she demonstrated at the Republican National Convention in 1972. Keller supported the issues of welfare reform, labor union rights, AIDS awareness throughout her life. Although politically active, she only made one expressly political film, Hell No: No Cuts!, which dealt with racism and the welfare system. At the time Keller was making her films, the feminist movement of the 1960s and 70's was in full swing; as a result of this movement, feminist film theory was applied to a majority of films made by women in that era. Keller rejected the structural rules and regulations based on feminist film theory. In a review of E. Ann Kaplan's 1983 book Women and Film Keller stated that theory "obfuscates women's film making in the name of feminism."

Keller refused to work within the confines set up by film theorists, many of whom have never made a film themselves. Because of this ideology, Marjorie Keller's work was shunned by the critical feminist world. Marjorie Keller's work exists in the experimental realm of the lyrical and the "diary" film styles pioneered by Stan Brakhage, Gregory Markopoulos, Marie Menken (all of whom are cited as being big influences. In her films, Keller experiences, she explored what it was like to be a feminist in the latter half of the twentieth century, in her own way. Children were an inspiration to her; this can be seen in both her writings. Marjorie Keller made over twenty-five films in her brief lifetime. Hell No: No Cuts!, ca. 1972: silent and white. She published a children's pop-up book that she wrote and illustrated herself titled The Moon on the Porch. At the time of her death, she was working on a book about women experimental filmmakers, never completed. In addition to being a filmmaker, author and scholar, Keller served on the board of directors of the Collective for Living Cinema and was the founding editor of their journal, Motion Picture from 1984 to 1987.

She was the head of The Film-Makers' Cooperative in New York for a period of time in the late 1980s, was a professor of film making and film history at the University of Rhode Island

Krishna Murari

Krishna Murari is a Judge of Supreme Court of India and former Chief Justice of Punjab and Haryana High Court. He was served as Judge of Allahabad High Court till his elevation as Chief justice of Punjab and Haryana High Court. Murari was born in a lawyer family of Uttar Pradesh, his uncle G. N Verma was a leading lawyer. Murari passed LL. B. from the Allahabad University, Allahabad. He was enrolled as an Advocate on 23 December 1981 and started practice in the Allahabad High Court on Civil, Constitutional and Revenue matters. In his 22 years law career, he served as Standing Counsel of Uttar Pradesh State Yarn Company, Northern Railway Primary Co-operative Bank, Uttar Pradesh State Textile Corporation etc, he appeared for Bundelkhand University of Jhansi. Murari was appointed as an Additional Judge of the Allahabad High Court on 7 January 2004 and became the Permanent Judge in 2005. On 2 June 2018 he was elevated in the post of the Chief Justice of Punjab and Haryana High Court in Chandigarh after the retirement of Justice Shiavax Jal Vazifdar.

He was elevated as Judge of Supreme Court of India on 23 September 2019