Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
National 5 Biology Key Area 6: The Need for Transport (b) Animal Transport Systems National 4 Biology Key Area 4 Growth and Development of different organisms By the end of this lesson you will be able to .... • Name the different parts of the respiratory system • Describe the function of rings of cartilage in the airways • Describe the structure of the alveoli • Describe the self-cleaning mechanism present in the lungs. Structure of the Lungs • Windpipe (trachea) • Has rings of cartilage around it • These rings help to keep the windpipe open! Structure of the Lungs • Bronchi (plural) • Bronchus (singular) • Connects the windpipe to the lungs • Also contains cartilage Structure of the Lungs • Bronchioles • Smaller tubes which branch out throughout the entire lung • End in air sacs Structure of the Lungs • • • • Air sac (alveolus) SITE OF GAS Air sacs (alveoli) EXCHANGE! As small as a grain of salt! Completely surrounded by blood capillaries http://www.footprintsscience.com/flash/Alveoli.swf TASK: label your diagrams Structure of the Lungs • • • • • • WORD BANK: Trachea Bronchus Bronchiole Alveoli (Air sacs) Lung Rings of cartilage Air sacs are covered with blood capillaries Oxygen enters the blood Carbon dioxide leaves the blood Bronchioles Air sacs A single air sac Each air sac is a hollow, thin-walled sac that is covered with Capillaries. This is where gas exchange takes place in the lungs Gas Exchange in an Alveolus Oxygen and carbon dioxide are exchanged through the alveolar walls Deoxygenated blood enters Alveolus is ONE CELL THICK Alveolus (air sac) CO2 out Dense blood capillary network O2 in Layer of moisture oxyhaemoglobin Oxygenated blood leaves Alveolus HIGH CONCENTRATION of CO2 LOW CONCENTRATION OF CO2 HIGH CONCENTRATION O2 Blood capillary LOW CONCENTRATION of O2 Why are the alveoli so good at Gas Exchange? 1. Alveoli have a large surface area 2. Alveoli have thin walls (only 1 cell thick!) 3. Alveoli have a good blood supply (surrounded by a dense network of blood capillaries) All of the above allow for more efficient diffusion of gases. Diffusion is the movement of a substance from an area of high concentration to an area of low concentration Add the arrows to your diagram! Add the arrows to your diagram! HIGH CONCENTRATION of CO2 in blood LOW CONCENTRATION OF CO2 HIGH CONCENTRATION O2 LOW CONCENTRATION of O2 in blood Diffusion of Gases in the alveolus • There is a high concentration of carbon dioxide in the blood capillary and a low concentration in the alveolus, SO carbon dioxide will diffuse OUT of the blood capillary and INTO the alveoli • There is a high concentration of OXYGEN in the ALVEOLUS and a low concentration in the BLOOD CAPILLARY, so OXYGEN will diffuse OUT of the ALVEOLUS and INTO the BLOOD CAPILLARY Healthy lungs! How are the lungs kept clean? MUCUS •Why are the lungs ‘shiny’ looking? •Are the lungs wet or dry? •What makes them like this? Mucus • Mucus is a sticky substance that lines our respiratory tract • It traps dirt particles and micro-organisms like bacteria and some viruses Microscope Slides Of Cilia light microscope slide (X1000) electron microscope slide X500,000 movement of cilia Cilia hairs Special features of the lungs • Rings of Cartilage – This helps to keep the main airways (trachea and bronchi) open and prevent them from collapsing • Mucus and Cilia – These help to keep the lungs clean – Mucus traps dirt and microorganisms and the rhythmic movement of the cilia beat the mucus up and away from the lungs Stick in your diagram! How do the lungs keep themselves clean?