The Physiology of Respiration

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     1  The Physiology of Respiration This presentation takes you through the basic anatomy and physiology of the respiratory system You can complete the questions in your GM402M workbook as you work through this presentation Keep clicking your mouse to take you through the presentation Module GM402M
     2  Why do we need to breathe? Breathing gets oxygen into the body so that cells can make energy Cells use this energy to contract muscles and power the thousands of biochemical reactions that take place in the cell every second Without oxygen, cells can’t make energy and without energy, cells would die
     3  IMPORTANT CONCEPT The supply of blood and oxygen to cells and tissues is called PERFUSION If perfusion stops then cells die
     4  Energy production Inside the cells most energy is made by the mitochondria. This energy is in the form of ATP* *adenosine triphosphate – a small packet of energy In the process of energy production……… Oxygen is consumed by the cells Carbon dioxide is produced as a waste gas Glucose fuels the process
     6  How do cells get their oxygen? Oxygen (O2) from the air in the lungs diffuses into the blood It is transported in the blood to the cells Oxygen diffuses from the blood into the cells
     7  How do cells dispose of their carbon dioxide? Carbon dioxide (CO2) from the cells diffuses into the blood It is transported in the blood to the lungs In the lungs carbon dioxide diffuses into the air and is breathed out
     8  Movement of O2 and CO2 between lungs and cells
     9  The anatomy of the Respiratory System The respiratory system consists of a series of tubes that transfer air from outside the body to the small air sacs in the lungs where gas exchange take place – the alveoli The diagram on the next page shows the basic layout of the system – label the diagram in your workbook
     10  Look at the structure of the respiratory system and label the diagram in your workbook
     11  Alveoli At the end of the smallest bronchioles are the alveoli There are millions of alveoli in each lung Alveoli are surrounded by a network of small blood vessels called capillaries
     12  Alveoli and adjacent capillaries
     13  Gas exchange in the alveoli Oxygen diffuses from the alveoli to the blood in the capillaries Carbon dioxide diffuses from the blood in the capillaries to the alveoli
     15  What is diffusion? Diffusion is a process that occurs when there is a difference in the concentration of a substance between two areas The substance, for example oxygen, will diffuse from an area of high concentration to an area of low concentration No energy is required from the body for this process
     17  Ventilation (breathing) It is the changes in pressure that cause air to enter and leave the lungs Breathing air in and out of the lungs – As the ribs rise and fall and the diaphragm domes and flattens, the volume and pressure in the lungs changes
     18  Ventilation (breathing)
     19  Ventilation (breathing) Inspiration (breathing in) Ribs rise and diaphragm flattens Volume increases and pressure decreases Air enters the lungs Expiration (breathing out) Ribs fall and diaphragm domes Volume decreases and pressure increases Air leaves the lungs
     20  Control of Ventilation As we exercise, the body needs to obtain more oxygen and remove more carbon dioxide (CO2) This is done by increasing the rate and depth of breathing An increase in carbon dioxide in the blood is the main trigger that increases the rate and depth of breathing
     21  Control of Ventilation Chemoreceptors in the respiratory centre in the brain stem’s medulla detect an increase in blood CO2 levels The intercostal and phrenic nerves increase the rate and depth of breathing Additional chemoreceptors on arteries near the heart monitor oxygen and blood acidity
     23  Diseases such as emphysema, bronchitis and asthma can impede the movement of gas between the alveoli and the blood CO2 levels can build up in the blood – known as hypercapnia This stimulates the chemoreceptors in the respiratory centre of the brain The rate and depth of breathing increases to expire more CO2 and reduce levels in the blood Response to hypercapnia
     24  Click the back button to return to the Respiration Tutorial web page where you can access additional study materials, including… End of slide show Additional study materials - more advanced information on respiration Respiration QUIZ (good preparation for the module test)