Exchange surfaces and breathing

Description

Biology (F211) Mind Map on Exchange surfaces and breathing, created by Nikita96 on 14/05/2013.
Nikita96
Mind Map by Nikita96, updated more than 1 year ago
Nikita96
Created by Nikita96 over 11 years ago
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Resource summary

Exchange surfaces and breathing
  1. Gas exchange
    1. Cells need to take in oxygen and excrete waste products like CO2
      1. Small organisms have a large SA:V ratio. Large organisms have a small SA:V ratio.
        1. Small organisms can diffuse directly into or out the surface membrane. Small distance and is quicker
          1. Large organisms have cells deep within the body, large distance. Difficult to exchange substance to supple a large volume through a small surface
          2. Trachea 2 bronchi bronchioles alveoli
            1. Gas exchange happens in the alveoli
              1. Surrounded by capillaries. O2 diffuses out of the alveoli in the blood and CO2 diffuses into the alveoli from the blood
            2. Gas exchange systems
              1. How the lungs are adapted
                1. Many alveoli provide large surface area
                  1. Alveolar and capillary epithelium are one cell thick, short diffusion pathway
                    1. Alveoli have a good blood supply, take away O2 and bring back CO2.
                      1. Breathing in and out keeps a fresh supply of air and concentration gradient high
                      2. Role of each tissue
                        1. Goblet cells
                          1. Secrete mucus that traps microorganisms and prevents them from reaching alveoli
                          2. Cilia
                            1. Wafts the mucus to the back of the throat to prevent lung infection
                            2. Elastic fibres
                              1. They stretch and recoil to help with breathing in and out
                              2. Smooth muscle
                                1. Allows the diameter of the lumen to be controlled.
                                2. Cartilage
                                  1. Provide support and stops the trachea from collapsing (in a C shape)
                              3. Breathing
                                1. Inspiration
                                  1. Expiration
                                    1. Intercostal and diaphragm muscles relax. Ribcage moves down and in, diaphragm becomes curved. Decreases volume of thorax and increases pressure in lungs. Air forced out
                                    2. Intercostal and diaphragm muscles contract. Ribcage moves up and out, diaphragm flattens. Increases volume of thorax. Lung pressure decreases. Air flows into the lungs
                                    3. Terms
                                      1. Tidal volume: volume of air in each breath at rest
                                        1. Vital capacity: maximum volume of air breathed in or out
                                          1. Breathing rate: how many breaths (p/min)
                                            1. Residual volume: air that remains in the lungs (1.5dm3)
                                              1. Expiritory/Inspiritory reserve: How much more air can be breathed in or out
                                              2. Spirometer
                                                1. Oxygen filled chamber, person breaths through a tube, movements recorded (spirometer trace), soda lime absorbs CO2.
                                                  1. Volume of air decrease because CO2 in absorbed
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