https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/lung-introduction/v/meet-the-lungs 2024-04-04T15:34:20.714536152Z Meet the lungs! Breathing in through the mouth or nose, air travels down the throat, through the Adam's apple or voice box, and into the lungs. The lungs, which look like an upside-down tree, direct air to tiny sacs called alveoli. Oxygen from the air enters the bloodstream, while waste carbon dioxide exits into the alveoli and is exhaled. This process is vital for human survival. Rishi Desai video https://cdn.kastatic.org/googleusercontent/uH7kTzlYMjpw2kX36_nrlBZ_1Q4BmB8OwW_tVhTLOdAD8DsUUgNrol2mUSTQgJpc4c3xwRT1iOcP2YQpTDjw5zqn Meet the lungs! Breathing in through the mouth or nose, air travels down the throat, through the Adam's apple or voice box, and into the lungs. The lungs, which look like an upside-down tree, direct air to tiny sacs called alveoli. Oxygen from the air enters the bloodstream, while waste carbon dioxide exits into the alveoli and is exhaled. This process is vital for human survival. https://cdn.kastatic.org/ka-youtube-converted/qGiPZf7njqY.mp4/qGiPZf7njqY.mp4 576 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/how-does-the-human-body-work/x0fe8768432761c62:breathing-and-exchange-of-gases/x0fe8768432761c62:the-respiratory-system/e/the-respiratory-system 2026-02-16T08:20:40.549554389Z The respiratory system Structure of the lungs, bronchial tree, details of exchange vs conducting parts, alveoli, thoracic chamber, and pleura. mahathi exercise https://www.khanacademy.org/science/biology/human-biology/circulatory-pulmonary/v/the-lungs-and-pulmonary-system 2023-09-14T11:22:40.102153098Z The lungs and pulmonary system Breathing is a vital process that allows our bodies to take in necessary oxygen and expel waste carbon dioxide. Air enters through the nose or mouth, journeys down the throat, and reaches the lungs via tubes called bronchi. These bronchi split into smaller tubes, bronchioles, ending in tiny air sacs known as alveoli. Oxygen crosses the alveoli membrane into our bloodstream, while carbon dioxide moves from the blood into the alveoli, ready to be exhaled. Sal Khan video https://cdn.kastatic.org/googleusercontent/NyToBnsug5GUIIcabg128TKMXw0XjH7O60403MS7bHx47wu9rho8CCYwLMQUb5zF84dmLHm-c2SnfMDd_G2jtlc The lungs and pulmonary system Breathing is a vital process that allows our bodies to take in necessary oxygen and expel waste carbon dioxide. Air enters through the nose or mouth, journeys down the throat, and reaches the lungs via tubes called bronchi. These bronchi split into smaller tubes, bronchioles, ending in tiny air sacs known as alveoli. Oxygen crosses the alveoli membrane into our bloodstream, while carbon dioxide moves from the blood into the alveoli, ready to be exhaled. https://cdn.kastatic.org/ka-youtube-converted/SPGRkexI_cs.mp4/SPGRkexI_cs.mp4 1233 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/health-and-medicine/respiratory-system/respiratory-system-introduction/e/intermediate-lung-quiz 2026-04-07T23:17:37.123726494Z Intermediate respiratory system quiz Intermediate Lung Quiz Rishi exercise https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/lung-introduction/v/the-bronchial-tree 2020-09-09T11:23:47Z The bronchial tree Follow the path of an oxygen molecule as it makes its way from your mouth down to an alveolus! Rishi is a pediatric infectious disease physician and works at Khan Academy. Rishi Desai video https://cdn.kastatic.org/googleusercontent/k_WYlERSD5SzPeI18LZ5g0SbnRTIIyRz_5vIWBPzX4S_bEzG6PqfR0r2MLy8LVO56dUISIsYk4bN05VdmwoqbTk The bronchial tree Follow the path of an oxygen molecule as it makes its way from your mouth down to an alveolus! Rishi is a pediatric infectious disease physician and works at Khan Academy. https://cdn.kastatic.org/ka-youtube-converted/Z-yv3Yq4Aw4.mp4/Z-yv3Yq4Aw4.mp4 767 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/health-and-medicine/respiratory-system/respiratory-system-introduction/e/lung-quiz 2026-04-07T23:17:37.123726494Z Introductory respiratory system quiz Questions Rishi Desai exercise https://www.khanacademy.org/science/health-and-medicine/respiratory-system/respiratory-system-introduction/e/advanced-lung-quiz 2026-04-07T23:17:37.123726494Z Advanced respiratory system quiz Advanced Lung Quiz rishi exercise https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/lung-introduction/v/how-does-lung-volume-change 2020-09-09T23:28:11Z How does lung volume change? Learn about how muscle contraction and lung recoil actually help the lungs change their volume with every breath! Rishi is a pediatric infectious disease physician and works at Khan Academy. Rishi Desai video https://cdn.kastatic.org/googleusercontent/Svp5O2K5VNRFki7UNLdrrwSaDaiog3zx0oHOj1Tfrgc_zszCADB68drM-ibzePQDHmUAlYJwWCXbAu0dpqAK4xoE How does lung volume change? Learn about how muscle contraction and lung recoil actually help the lungs change their volume with every breath! Rishi is a pediatric infectious disease physician and works at Khan Academy. https://cdn.kastatic.org/ka-youtube-converted/dTsUyXXudvA.mp4/dTsUyXXudvA.mp4 490 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/lung-introduction/v/inhaling-and-exhaling 2023-08-17T23:33:36.770424498Z Inhaling and exhaling Find out exactly why air goes in and out of the lungs. Discover how changes in lung volume affect air pressure, leading to the movement of air molecules in and out of the lungs. This process, crucial for respiration, is explained using a simple jar analogy. Rishi is a pediatric infectious disease physician and works at Khan Academy. Rishi Desai video https://cdn.kastatic.org/googleusercontent/SQkfgiCLzTh4R0AaTjEc2gRwVwDpZBjzLDmWoFgNl9aRs3O6Zzk9Im888XuR9CAHjiXnSAlgQiKv7AtZJGWNK39hkQ Inhaling and exhaling Find out exactly why air goes in and out of the lungs. Discover how changes in lung volume affect air pressure, leading to the movement of air molecules in and out of the lungs. This process, crucial for respiration, is explained using a simple jar analogy. Rishi is a pediatric infectious disease physician and works at Khan Academy. https://cdn.kastatic.org/ka-youtube-converted/mykrnTh1tz8.mp4/mykrnTh1tz8.mp4 779 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/up-biology-grade-11-revision-course-full-term/x01ceb15d0be61009:week-2/x01ceb15d0be61009:untitled-589/e/mechanism-of-breathing 2025-01-29T06:48:52.84441926Z Mechanism of breathing Inspiration, expiration, intrapulmonary pressure gradients, intercostal muscles, diaphragm. mahathi exercise https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-hematologic/v/hemoglobin-moves-o2-and-co2 2020-09-09T11:23:52Z Hemoglobin moves O2 and CO2 Learn the two ways that oxygen moves from the lungs to the tissues, and the three ways that carbon dioxide returns from the tissues to the lungs. Rishi is a pediatric infectious disease physician and works at Khan Academy. Rishi Desai video https://cdn.kastatic.org/googleusercontent/HOI9b9WyfLwPbGDb-HOalXmb-CM3QtzCguqN__wh4UJpneNSv3oOb3AWIaPf9qklhYwANAqWpB9rY1KtmLn_XTDRaw Hemoglobin moves O2 and CO2 Learn the two ways that oxygen moves from the lungs to the tissues, and the three ways that carbon dioxide returns from the tissues to the lungs. Rishi is a pediatric infectious disease physician and works at Khan Academy. https://cdn.kastatic.org/ka-youtube-converted/QP8ImP6NCk8.mp4/QP8ImP6NCk8.mp4 898 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/up-biology-grade-11-revision-course-full-term/x01ceb15d0be61009:week-2/x01ceb15d0be61009:untitled-589/e/exxhange-of-gases 2026-01-24T15:20:42.617490009Z Exchange of gases Partial pressure, pressure gradients of oxygen and carbon dioxide, diffusion membrane mahathi exercise https://www.khanacademy.org/science/health-and-medicine/respiratory-system/gas-exchange-jv/v/o2-and-co2-solubility 2020-10-22T19:06:22Z O2 and CO2 solubility Get an intuition for why carbon dioxide is so much more soluble than oxygen when it goes into water. Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Rishi Desai video https://cdn.kastatic.org/googleusercontent/n_pUY89ydKwGh_qJUQXcb8bgVzquZTEg8aPnarUnQYVHHHFyVaH-pGwkUPD6hiFAWGokerkxStldQAJuak-oZYczQA O2 and CO2 solubility Get an intuition for why carbon dioxide is so much more soluble than oxygen when it goes into water. Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. https://cdn.kastatic.org/ka-youtube-converted/OCD4Dr3kmmA.mp4/OCD4Dr3kmmA.mp4 465 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/health-and-medicine/respiratory-system/gas-exchange-jv/v/oxygen-movement-from-alveoli-to-capillaries 2020-07-15T21:03:18Z Oxygen movement from alveoli to capillaries Watch as a molecule of oxygen makes its way from the alveoli (gas layer) through various liquid layers in order to end up in the blood. Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Rishi Desai video https://cdn.kastatic.org/googleusercontent/JYgZsC4G9QfpXt_TsIoFLuvK2b6ynrClVFcggMi326ms7Wx6ogiKmOP5Gc0R7xRArwD8fmiI_MzkGqanNAF7gD_T Oxygen movement from alveoli to capillaries Watch as a molecule of oxygen makes its way from the alveoli (gas layer) through various liquid layers in order to end up in the blood. Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. https://cdn.kastatic.org/ka-youtube-converted/nRpwdwm06Ic.mp4/nRpwdwm06Ic.mp4 706 Introduction to respiration and mechanism of respiration https://www.khanacademy.org/science/up-biology-grade-11-revision-course-full-term/x01ceb15d0be61009:week-2/x01ceb15d0be61009:untitled-589/e/transport-of-oxygen-and-carbon-dioxide 2026-01-24T15:20:42.617490009Z Transport of oxygen and carbon dioxide Hemoglobin, oxyhemoglobin, carbamino-hemoglobin, carbonic anhydrase, bicarbonate mahathi exercise https://www.khanacademy.org/science/biology/human-biology/circulatory-pulmonary/v/hemoglobin 2021-03-18T10:33:24Z Hemoglobin Hemoglobin and its role in the circulatory system. Sal Khan video https://cdn.kastatic.org/googleusercontent/3rIvN6eaCFkywv2dH0eLk0fVptF-FIrX232nb7FKxs2nLQm9rFGKDyIL2izN0IEcX7AISOjEXerEKh2zoaj5vSfG Hemoglobin Hemoglobin and its role in the circulatory system. https://cdn.kastatic.org/ka-youtube-converted/LWtXthfG9_M.mp4/LWtXthfG9_M.mp4 874 Introduction to respiration and mechanism of respiration