Presentation on theme: "Functions of the Respiratory system"— Presentation transcript:
1Functions of the Respiratory system P6 M3Functions of the Respiratory system
2General description The respiratory system is responsible for: getting oxygen in to our bodyGetting carbon dioxide and other waste products out of our bodyAll living creatures need Oxygen in combination with food to produce energy and movement.Every cell of the body needs Oxygen to functionRespiration is the process by which cells receive a constant supply of oxygen and carbon dioxide is removed.
3General description… The aim of the respiratory system is to get: Oxygen to the bloodstreamso that the CV system can deliver it to the muscles.Carbon dioxide out of the bloodstreamAll endurance performance relies onDelivery of Oxygen into the blood streamRemoval of Carbon Dioxide out of the bloodGive a couple of specific examples in your worksheetGeneral description…When we exercise: CO2 dissolves within the bloodstream and increases acidity levels. So the respiratory centre in the brain speeds up the rate of breathing to get rid of excess CO2.So rate of breathing increases due to CO2 levels rising. Not the cells demanding more O2.
4Gaseous Exchange: Diffusion Gases move through a process called diffusionGas moves from a high concentration to a low concentrationEg: someone wearing perfume.In the respiratory systemTwo different types of diffusion:Diffusion of Oxygen into the blood stream, attracted by haemoglobinDiffusion of Carbon Dioxide out of the blood stream to be excreted by the lungs
5Diffusion of Oxygen into the blood stream The alveoli are in constant contact with the capillariesThe air we breath in arrives in the alveoli, rich in OxygenThe blood arrives from the pulmonary artery very low in oxygenFollowing the principle of diffusion, the Oxygen moves across the capillary wall and into the blood streamIt is attracted by the haemoglobin into the red blood cellsThe blood returns to the heart to be pumped to the rest of the body
6Diffusion of Carbon Dioxide out of the blood stream The blood arrives in capillaries of the lungs with a high concentration of Carbon DioxideThe air in the alveoli has a low concentration of Carbon DioxideAccording to the principles of diffusion, the Carbon dioxide moves across the wall of the capillaries and into the alveoli, so that it can be expired.
7The mechanics of breathing Breathing is regulated by:the respiratory centre, located in the brain.Receptors in the air passages and lungsBreathing in = InspirationBreathing out = ExpirationTo breathe the thorax must increase and then decrease in sizeOverview
8InspirationIn order to breathe in the volume of the chest cavity needs to increase.This increase in size of the chest cavity, causes a decrease in pressure within the lungsBoyle’s Law states that a volume of gas is inversely proportional to its pressure.This means that the increase in volume in the lungs causes a decrease in pressure.Gases flow from a high pressure area to a low pressure areaIn this situation the ambient air is the high pressure area and the lungs are the low pressure area, so the air flows into the lungs
9Inspiration Inspiration – Breathing in Diaphragm contracts It flattens and pulls downThis is an active processExternal intercostal muscles contractThe sternum moves up and out, with the lungs followingThe lungs are attached to the pleural sac (containing pleural fluid), which in turn is attached to the thoracic cageAs the chest expands, the surface tension, created by the film of pleural fluid causes the lungs to be pulled outwards, with the chestThese two actions cause the volume of the thoracic cavity to increaseAccording to Boyles Law this increase in volume causes a decrease in pressureAir flows into the lungsAs gas flows from high pressure to low pressure.
10Expiration To breathe out – Expiration: Diaphragm relaxes It moves back up and into the thoracic cavityThis is a passive processThe external intercostal muscles relaxThe ribs/sternum moves down.The lungs, sternum and rib cage are elastic structures that naturally 'spring' back to their resting positions once the forces of the inspiratory muscles are removed. So expiration is a passive process.The volume of the thoracic cavity decreases causing the air to move out of the lungs.This is because air pressure in the lungs is now higher than atmospheric pressure, according to Boyles Law, so the air is forced out of the lungs to equate the pressure in and out of the body.
13Lung VolumesLung volumes: refers to physical differences in lung volume, while lung capacities represent different combinations of lung volumes, usually in relation to inhalation and exhalation.The average pair of human lungs can hold about 6 litres of air, but only a small amount of this capacity is used during normal breathing.
15Respiratory volumes Tidal Volume The volume of air inspired or expired per breath (Approx 500ml at rest)Inspiratory Reserve VolumeThe amount of space that is available to draw in more airEg; Breathe in normally, then breathe in more. This extra capacity is your IRVExpiratory Reserve VolumeThe amount of space that is available to breathe out, once you have exhaled normallyEg: Breathe out normally, then force out more air. This is your ERV.
16Respiratory volumes Residual Volume Vital Capacity Total Lung Capacity Take in as much breath as possibleThis is your total lung capacityERV+IRV+TV+RV (Approx 6000ml)Residual VolumeBreathe out as much as possibleThere is always some air left in your lungsThis is your RV (Approx 1200ml)Vital CapacityBreathe in as much as you can, and then force as much air out of your lungs as possible.This is your IRV+ERV+TV, and is your Vital Capacity
172. Function: Examine the respiratory system Describe the (1) Structure with all the parts named BELOW and (2) Function (1-4 BELOW) of the respiratory system.Examine the respiratory systemand explain how it works and how each part of the system is designed to meet its function1. Structure of the respiratory system:Nasal cavityEpiglottisPharynxLarynxTracheaBronchusBronchiolesLungs (lobes, pleural membrane, thoracic cavity, visceral pleura, pleural fluid, alveoli)DiaphragmIntercostal muscles (external and internal)2. Function:1. Gaseous exchange2. Mechanisms of breathing (inspiration and expiration)3. Lung volumes: e.g. tidalvolume, vital capacity, residual volume4. Control of breathing (neural and chemical)