Capillaries have very thin walls – only one cell thick. This makes them thin enough for gases for nutrients to pass through them. Capillaries occur in large quantities around the muscles and this enables effective exchange of gases.
Inhalation
Inhalation is initiated by the and supported by the external intercostals muscles. Normal resting respirations are 10 to 18 breaths per minute. Its time period is 2 seconds. During vigorous inhalation (at rates exceeding 35 breaths per minute), or in approaching respiratory failure, then the accessory muscles of respiration are recruited for support.
Inhalation is driven primarily by the diaphragm. When the diaphragm contracts, the ribcage expands and the contents of the abdomen are moved downward. This results in a larger thoracic volume. As the pressure in the chest falls, air moves into the conducting zone. Here, the air is filtered, warmed, and it flows to the lungs.
During forced inhalation, as when taking a deep breath, the external intercostals muscles and accessory muscles expand further the thoracic cavity.
Exhalation
is generally a passive process, however active or forced exhalation is achieved by the abdominals and the internal intercostals muscles.
The lungs have a natural elasticity; as they recoil from the stretch of inhalation, airflows back out until the pressures in the chest and the atmosphere reach equilibrium.
During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominals and internal intercostals muscles, generate abdominal and thoracic pressure, which forces air out of the lungs.
Circulation
The right side of the heart pumps blood from the through the pulmonary semilunar valve into the pulmonary trunk. The trunk branches into right and left pulmonary arteries to the pulmonary blood. The vessels generally accompany the airways and also undergo numerous branchings. Once the gas exchange process is complete in the pulmonary capillaries, blood is returned to the left side of the heart through four pulmonary veins, two from each side. The pulmonary cirulation has a very low resistance, due to the short distance within the lungs.
Virtually all the body's blood travels through the lungs every minute. The lungs add and remove many chemical messengers from the blood as it flows through pulmonary capillary bed. The fine capillaries also trap blood clots that have formed in systemic veins.
Gas exchange
The major function of the respiratory system is gas exchange. As gas exchange occurs, the acid-base balance of the body is maintained as part of homeostasis. If proper ventilation is not maintained two conditions could occur: 1) respiratory acidosis, a life threatening condition, and 2) respiratory alkalosis
Upon inhalation, gas exchange occurs at the alveoli, the tiny sacs that are the basic functional component of the lungs. The alveolar walls are extremely thin. The alveoli are lined with pulmonary capillaries, the walls of which are also thin enough to permit gas exchange. All gases diffuse from the alveolar air to the blood in the pulmonary capillaries, as carbon dioxide diffuses in the opposite direction, from capillary blood to alveolar air. At this point, the pulmonary blood is oxygen-rich, and the lungs are holding carbon dioxide. Exhalation follows, thereby ridding the body of the carbon dioxide and completing the cycle of respiration.
In an average resting adult, the lungs take up about 250ml of oxygen every minute while excreting about 200ml of carbon dioxide. During an average breath, an adult will exchange from 500 ml to 700 ml of air. This average breath capacity is called tidal volume.
Respiratory system
The trachea is sometimes called the windpipe. It is lined with a mucous membrane and ciliated cells, which trap dust, and contains 18 rings or cartilage to keep it open and protect it. The trachea goes from the larynx to the primary bronchi.
The bronchi and bronchioles are two parts to the trachea. The right bronchus goes into the right lung and the left bronchus goes into the left lung. The bronchi then divide up into smaller bronchioles. The bronchioles enable the air to pass into the alveoli, where diffusion takes place.
Alveoli are tiny air-filled sacs for gaseous exchange between the lungs and the blood. There are many millions alveoli in the lungs, which provides an enormous surface area. The walls of the alveoli are extremely thin and moist, which allows oxygen from the air to dissolve.
The Lungs lie in the thoracic cavity, which is protected by the ribs and separated into two. The pleural membrane that centres the pleural cavity surrounds each of the two lungs. The pleural cavity contains pleural fluid, which reduces friction on the lungs when breathing. The diaphragm borders the bottom of the lungs and is a sheet of skeletal muscle.
A practical investigation was then carried out for both the cardiovascular system and the respiratory system. We did an aerobic test and an anaerobic test. The first one we did was the aerobic test, which was done for 16 minutes and had to be 65% of the maximum heart of the participant. A number of results were taken before the investigation was carried out. The first was Tom Mustoes resting rate so that we could see how hard he is working. The second was the O2 room level, which was 18.89 and also the CO2 level, which was 0.16. Also his resting lactate level was taken and it was 7.49. To get this test right we used a number of pieces of equipment. The heart rate monitor was used to strap round the participants diaphragm so that his heart could be monitored at a regular rate. Douglas bags were used every four minutes so that we could access how mush oxygen and carbon dioxide intake there was. Also at this stage the blood lactate is taken to see how well the oxygen is going through the blood.
When looking at the table I have produced I have circled the anomalies and I will now tell you why that was the reason. When looking at the heart rate column there are three results that are out of place the top two are counted as VOID and the reason for that is that Tom was walking to far away from the heart rate signal when he had the heart rate monitor on. So this was corrected and that’s why we have results for the remaining minutes. At the seventh minute the heart rate was too high and that was because the speed of the treadmill was too fast and he was work at more than 65% of his maximum heart rate. On the last two blood lactate tests they became VOID as well. There was no really answer for this only that no blood reading could be taken in the 30 second time limit that was given.
Aerobic Training
There are many different types of endurance athletes around, such as long distance runners, long distance swimmers, cyclists and many more. The key to these performers being successful is the ability to last for a long time whilst staying at the peak of their capabilities. To do this they must have extremely good cardiovascular, respiratory, muscular and aerobic energy systems.
Aerobic endurance performers work on the same training on the basis that the cardiovascular system is specifically used. This is basically using the heart, lungs, arteries and veins, this will increase the blood volume and haemoglobin levels, and so the oxygen-carrying capacity of blood is enhanced. When his fitness was improving because he is at a peak were he will not get much fitter his arteries will have expanded becoming more efficient and more elastic letting more blood through. The cardiac response is much greater in an aerobic athlete because they’re working more on their heart this will increase the size of the heart and make it stronger. Hypertrophy, which is the enlargement of the heart, will increase the thickness and strength of the left ventricular wall this causes an increase in the stroke volume and a lowering of the resting pulse. This is why Lance Armstrong’s heart rate is 32-34 bpm.
Stroke volume is how much blood is in the left ventricle of the heart and this will be higher for a trained athlete. In response to the demand for oxygen, more lung alveoli are utilised and hence the lungs have a greater surface for gaseous exchange. The capillary network surrounding the alveoli increases and therefore the alveolar capacity for oxygen transfer is enhanced. The quicker you get the blood into the lungs the quicker gaseous exchange takes place and this will be more efficient the fitter you are. The increase in strength of the respiratory musculature makes the lung capacity have a slight increase and this is because the thoracic capacity becomes more capable of contracting and expanding. Enlarging the vital capacity at the expense of the residual volume enhances tidal volume; this enables air in larger volumes per intake to be breathed and exhaled more rapidly and has the effect of developing a more efficient breathing system and potentially increasing o2max. When the heart and lungs are more adaptable too exercise and this makes the efficient recovery time to decrease. When oxygen recovery improves then lactic acid removal is more frequent, this will also reduce the soreness in the muscles.
When large forces are repeatedly applied this makes the articular cartilage thicker and more compressible, which also provides more cushioning to the ends of long bones under impact. Endurance training increases the ability of muscles to work harder and utilise more oxygen without bringing in the lactic acid energy system above the resting rate. Endurance training therefore delays the onset of blood lactate accumulation. The harder you train the more sweat is produced, thermoregulation centre, which is situated in the hypothalamus, is sensitive to the temperature of the blood and sends out impulses to the skin. It has been found that when training ceases the effects from the training are established for a longer period.
Anaerobic Based Performer
There are also many anaerobic athletes in the world of sport too. These include people such as sprinters, weightlifters, gymnasts and many more. The key factors to being a top anaerobic athlete is the ability to be able produce a lot of energy in a short amount of time to produce a powerful but controlled performance.
Anaerobic athletes do overload training and by doing this fast twitch fibres respond when large forces are applied to a given muscle, this is the muscles hypertrophy. With the increase in muscle width more actin and myosin are assimilated and this therefore increases the strength of each fibre because more contractile protein allows for more cross bridges to be formed. The fast twitch fibres occupy a greater cross-sectional area when compared with slow-twitch fibre content of a given muscle, where as highly trained aerobic athletes the reverse situation is found. All this allows more pressure to be exerted in a short space of time giving a powerful performance.
There is also a neural response in the body to training, the increase in the recruitment of fast-twitch motor units and improved co-ordination of the firing of fast-twitch motor units to allow increases in strength and this allows means a toughening in proprioceptors so that force is required to stimulate inhibitory signals.
There is a huge enhancement of the ATP-PC energy system and if exercises require large amounts of instant energy lasting less than 10 seconds and are repeated with full recovery between repetitions, then an adaptation takes place in which stores of ATP and PC increase. This means more energy is available a lot more rapidly and it also increases the maximum possible peak power output for an anaerobic performer. If the other energy systems are not stressed then it is found that these reduce the comparison with the ATP-PC system.
If overloads are experienced for periods of up to 60 seconds then it is found that glycogen stored in muscles are enhanced. This means that the muscles use the glycogen to enhance their performance and it will control the lactic acid production, so that you as an anaerobic performer can perform for a longer time at a highly powered and controlled level meaning that performance will be more successful, this is completely different to aerobic athletes aims as they look to perform for a long time with no the greatest amount of power and speed where as anaerobic athletes are looking to give a performance producing a lot of speed and power in a short space of time.
As and anaerobic athlete is important to do a lot of strength, flexibility and speed work because all these are needed for a performer to be able to perform at the top of their ability. If you do all these types of training your muscles will get bigger and stronger and you will get quicker and will be less likely to get injured as well.
Biological adaptations are a long-term process and most of the adaptations mentioned take months or years to establish completely. Once established, these adaptations promote greater general and specific fitness, which will remain with the performer even if exercise stops. As an anaerobic performer if you train for a long time and get very strong and very quick and powerful and then just stop most adaptations would return to the untrained state but again this would be a long-term process. Conversely, although intense daily training can increase performance dramatically over a short period of time, there are no biological adaptations, which would maintain fitness though once exercise had stopped.
Increased flexibility also is a big advantage because it means the performer can perform short bursts off high energy and high-pressured movements whilst having a less chance of getting injured. They will also be able to make movements that they may not of been able to make and this will help them with their performance and well as making them more flexible it will also improve their speed and their injury prevention.
So to conclude the anaerobic and aerobic systems are both extremely different and have completely different adaptations when they are trained for a long time. The anaerobic is all about power and all about doing things in a short space of time using up a lot of energy where as on the other hand aerobic is using a lot of energy over a long period of time and doing things a lot less powerfully and under less pressure. When performing at the top level of you sport both of these are as hard as each other because both ask different physical requirements and sometimes both, even though they are completely contrasting, can have the exact same outcome on the performers body.
