Alveoli And Alveolar Membrane
American Lungs Association and research evidence concluded that there are 480 million alveoli in each of lungs, and alveoli are tiny air sacs with their outer covering membrane, surrounded by a dense network of blood capillaries. The structure of alveoli is composed of numerous cell types, but the two types of alveolar cells that are more distinguished in their functions are Pneumocytes Type I and Type II cells. Type II cells are resistant to toxic chemical insult and respond to an emergency by differentiation and proliferation. Whereas, type I pneumocytes are none resistant and non proliferating in nature. Alveoli play a vital role in the uptake of oxygen molecules and their further propagation across the blood-air-barrier to move from lungs to the blood. On the other hand, in exchange for oxygen molecules, carbon dioxide diffuses out of the alveoli into the upper airways to move towards the outer atmosphere.
WHAT IS THE PROCESS WHEN OXYGEN MOLECULES MOVES FROM LUNGS Into THE BLOOD?
The carbon dioxide and oxygen move from lungs into the blood involves the following process to be carried on continuously.
- PULMONARY VENTILATION
It is the delivery of oxygen-rich-air from the atmosphere through the respiratory tract to the alveoli.
- EXTERNAL RESPIRATION
It is the diffusion of carbon dioxide and oxygen molecules across the blood-air-barrier to and from the blood and alveoli
- TRANSPORT OF GASES
Gaseous transportation is an intermediate stage where the oxygen and carbon dioxide propagate into the bloodstream to reach their desired destinations.
- INTERNAL RESPIRATION
Internal respiration occurs at the tissue level, where oxygen diffuses out of the blood into the tissues, and carbon dioxide diffuses out of tissues into the interstitial fluid at the systemic capillary level.
- CELLULAR RESPIRATION
It takes place in the cell’s mitochondria, where oxygen is utilized, ATP is manufactured, and carbon dioxide is released as a by-product.
DIFFERENCE BETWEEN VENTILATION AND OXYGENATION
Ventilation and oxygenation are the two marked processes but directly proportional to each other. Moreover, Ventilation is the propagation of oxygen-rich-air to the alveoli, and oxygenation is the diffusion of dissolved oxygen molecules into the tissues after perfusion.
GASEOUS EXCHANGE/ OXYGEN AND CARBON DIOXIDE EXCHANGE
GASEOUS EXCHANGE AND ITS PRINCIPLES
The gaseous exchange occurs in the alveoli and across the blood-air-barrier, characterized by the diffusion of oxygen molecules from the inhaled air in the bronchioles to the blood in the alveolar capillaries. Additionally, a diffusion of carbon dioxide molecules from the alveolar capillaries to the exhaled air in the bronchioles.
Gaseous exchange is also termed external respiration and is based on three principles.
WHAT IS CARRIER PROTEIN?
Hemoglobin is the also known as carrier protein throughout the bloodstream as hemoglobin has two binding surfaces. Firstly, for oxygen molecule and the other for carbon dioxide molecule. As the oxygen diffuses into the bloodstream, it is immediately take-up by the hemoglobin, and carbon dioxide gets released into the alveoli and then out of the lungs.
HOW CAN WE GET MORE OXYGEN INTO THE BLOODSTREAM?
Typically you can manipulate the oxygen uptake by increasing and decreasing your respiratory rate and depth by the following maneuvers.
- Stay hydrated
- Eat green leafy vegetables
- Eat iron-rich foods
- Moreover, take iron supplements if the food does not fulfill your dietary requirements
- Train your respiratory system by doing breathing exercises, including active breathing technique (ACBTS), Interdigital technique (IDTS), Forced expiratory technique, Incentive spirometry, Blowing exercises, Pursed lip breathing, Diaphragmatic breathing, and also Alternate nostrils breathing technique.
- Aerobic exercise
- Do your activities in a fresh environment because one need to consume fresh air.
Following are structural and functional disorders of the respiratory system that may interrupt the propagation of oxygen and carbon dioxide molecules at any stage of the entire pathway of human respiration.
STRUCTURAL INSUFFICIENCY OF THE RESPIRATORY SYSTEM
- Alveolar microlithiasis
- Lung cancer
FUNCTIONAL INSUFFICIENCY OF THE GASEOUS EXCHANGE MECHANISM
- Chronic Obstructive Lung Disease
- Acute Respiratory Distress Syndrome (ARDS)
- Infant Respiratory Distress Syndrome (IRDS)
- Alveolar Collapse
Aging should not be overlooked as it also naturally compromise the respiratory system.
In conclusion, the human respiratory system is complicated structurally and functionally. Moreover, millions of its involved micro structures fulfill their tasks within microseconds without any delay at any stage. The gaseous exchange occurs using diffusion, which is based on the transport of oxygen and also carbon dioxide molecules across the blood-air-barrier. The oxygen molecules then transport through the capillary system in the blood circulation, reaching their destination at the tissue level in the systemic capillaries; it diffuses across the cell membrane into the cell where it is further processed into the mitochondria to generate energy in the form of ATP and liberate carbon dioxide as a by-product. Hence, this is all about how oxygen molecules move from lungs in to the blood.
Lastly, Do not forget to do some workouts for your lungs by breathing exercises; then make your respiratory system a healthier and strongest one.
RESEARCH ARTICLES AND RELATED LINKS
- Bassingthwaighte, J. B., Raymond, G. M., Dash, R. K., Beard, D. A., & Nolan, M. (2016). The Pathway for Oxygen: Tutorial Modelling on Oxygen Transport from Air to Mitochondrion: The Pathway for Oxygen. Advances in experimental medicine and biology, 876, 103–110.
- Hsia, C. C., Hyde, D. M., & Weibel, E. R. (2016). Lung Structure and the Intrinsic Challenges of Gas Exchange. Comprehensive Physiology, 6(2), 827–895.
- How does oxygen get into the bloodstream?
- Exchanging Oxygen and Carbon Dioxide.
- Christin Reminga, Lesley G. King. Oxygenation and ventilation.Monitoring and Intervention for the Critically Ill Small Animal: The Rule of 20.18 October 2016.
- HOW LUNGS WORK.