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Ventilation Noadswood Science, 2012 Friday, April 8, 2016 Ventilation To know how ventilation takes place in the body Exercise Make a list of all the things which occur to your body when you exercise – next to these write a short description explaining these changes and why they occur… Exercise When you exercise your body tries to maintain a constant internal environment – in order to do this is needs to regulate many processes As soon as exercise begins you’ll notice more frequent muscle contraction, raised body temperature and pulse, and deeper breathing (tidal volume) Longer-term effects occur as the body adapts to regular exercise, including your heart getting larger, bones becoming denser and the vital capacity of your breath deepening Cardiovascular System Immediate effects: – Increased heart rate and stoke volume (more powerful contraction allowing for greater pump volume) – Blood diverted to muscles from digestive system – Blood temperature rise – Blood vessels near skin allow for heat loss Regular training effects: – Heart muscle increases in size and strength and cardiac output increases (blood pumped) – Lower resting heart rate and quicker recovery – Reduced risk of heart disease – Increased blood volume and red blood cells – Increased number of capillaries in muscle Respiratory System Immediate effects: – Increased rate of breathing – Increase in tidal volume (amount of air breathed in) Regular training effects: – Strength of diaphragm and intercostal muscles – Increased number of alveoli – Increase in vital capacity (amount of air that can be forcibly exhaled after breathing – Increase in O2 delivery and CO2 removal Respiratory System What does the respiratory system do? What parts does it consist of? The respiratory system contains the organs that allow us to get the oxygen we need and to remove the waste carbon dioxide It consists of: – Lungs (in upper part of body (thorax)) – Tubes leading from the lungs to the mouth and nose – Various structures in the chest that allow air to move in and out of the lungs Respiratory System Movements of the ribs, rib muscles and diaphragm allow air into and out of the lungs: this is called breathing or ventilation – when we breathe in, we inhale and when we breathe out, we exhale Air passes between the lungs and the outside of the body through the trachea The trachea divides into two bronchi, with one bronchus for each lung Each bronchus divides further in the lungs into smaller tubes called bronchioles At the end of each bronchiole, there is a group of tiny air sacs called alveoli Breathing / Ventilation Breathing in (inhale) - ribs move up and out, diaphragm contracts (pulled down) Breathing out (exhale) - ribs move down and in, diaphragm relaxes (moves upward) Breathing Complete the breathing worksheet - stick this in your book (plus all other work) Breathing Gas Exchange For respiration to occur, we need to get oxygen from the air to the blood, and remove waste carbon dioxide from the blood Alveoli in the lungs are adapted to make gas exchange happen easily and efficiently: they cause the lungs to have a very large surface area; are moist with thin walls; and have many capillaries The gases move via diffusion (net [high] to [low]) Summary The breathing system allows for gas exchange - it needs to be as efficient as possible (alveoli have thin walls and very large surface areas (about the same area as a tennis court if laid flat)! Summary Oxygen is transferred into the blood, and carbon dioxide out of it via diffusion (net movement from high concentration to low concentration)… Lung Dissection Observe the lung dissection and try and identify the key areas and how they allow for gaseous exchange…