GCSE Physical Education

• The main function of the respiratory system is to exchange gases between the body's cells and the external environment.
• During exercise, more oxygen is required to produce energy, leading to an increase in ventilation rate and depth.
• Oxygen enters the lungs through the nose or mouth, passes into the alveoli (tiny air sacs), diffuses across the walls of the capillaries surrounding them, and then travels around the body via the bloodstream.
• Oxygenated blood travels through pulmonary veins to the left side of the heart, while deoxygenated blood returns from the right side of the heart via vena cavae.
• Carbon dioxide leaves the body by passing from the capillaries into the alveoli, where it can be exhaled during breathing out.
• Gas exchange occurs at the alveoli, where oxygen diffuses into the bloodstream and carbon dioxide diffuses out.
• Oxygen enters the lungs through the nose or mouth, passes into the alveoli (tiny air sacs), diffuses across the walls of the capillaries, and then travels around the body via the bloodstream.
• Ventilation rate refers to how many times air enters or leaves the lungs per minute, while ventilation depth refers to the volume of air that enters or leaves the lungs with each breath.
• Increased ventilation during exercise can be achieved through increased breathing frequency (rate) and/or tidal volume (depth).
• Carbon dioxide leaves the body during exhalation as it is less soluble than oxygen.
• Tidal volume is the amount of air breathed in and out at rest.
• Increased activity leads to increased demand for oxygen, resulting in faster and deeper breathing.
• Increased breathing rate and tidal volume are adaptations that occur during exercise to meet increased demand for oxygen.
• Breathing becomes rapid and shallow as the diaphragm contracts less forcefully, allowing the chest cavity to expand more easily.
• Breathing becomes more rapid as the diaphragm contracts more frequently, increasing tidal volume.
• Ventilatory threshold occurs when there is a shift towards using carbohydrates instead of fats as fuel due to limited oxygen supply.
• Respiration rate increases due to greater contraction frequency of the diaphragm and intercostals muscles.
• The respiratory system is responsible for gas exchange between the environment and the cells of the body.
• Respiration involves the intake of oxygen and release of carbon dioxide.
• During exercise, there are changes in both ventilation rate and depth as the body demands more oxygen.
• Increased ventilation rate allows for increased oxygen intake, while increased ventilation depth increases the amount of oxygen available for diffusion.
• During inspiration, muscles contract to increase lung volume, decreasing pressure inside the lungs compared to outside. Air flows down its concentration gradient from high to low pressure, entering the lungs.
• Inspiration is the process of taking in air, while expiration is the process of releasing air.
• During inspiration, the diaphragm contracts downwards and the external intercostal muscles contract upwards, increasing thoracic cavity size and decreasing pressure inside the chest.
• During expiration, the ribcage returns to its original position and the diaphragm relaxes, decreasing lung capacity.
• Air flows into the lungs due to the difference in pressure between the outside environment and the thorax.
• The respiratory system includes the trachea, bronchi, bronchioles, alveoli, diaphragm, intercostals muscles, pleurae, and lungs.
• During inspiration, the ribcage expands and the diaphragm contracts, increasing lung capacity.
• During inspiration, the diaphragm contracts downwards and the external intercostals contract upwards, increasing thoracic cavity volume and decreasing pressure inside the chest.
• During expiration, muscles relax, increasing pressure inside the lungs compared to outside. Air flows up its concentration gradient from low to high pressure, leaving the lungs.
• The respiratory system consists of the trachea, bronchi, bronchioles, alveoli, diaphragm, intercostals muscles, pleural membranes, and lungs.
• Increased activity levels lead to increased demand for oxygen, resulting in an increase in ventilation rate and depth.
• The respiratory system consists of the upper respiratory tract (nose, pharynx, larynx, trachea) and lower respiratory tract (bronchi, bronchioles, alveoli).
• The respiratory system works with other systems such as the circulatory system to deliver oxygen to muscles and remove carbon dioxide from them.
• Air flows from high to low pressure, so more air rushes in to fill the space created by the increase in thoracic cavity size.
• The respiratory system works with other systems such as the cardiovascular system to deliver oxygen to muscles.
• During exercise, there is an increase in heart rate, stroke volume, and cardiac output to supply oxygen-rich blood to working muscles.
• During exercise, there is an increase in cardiac output due to increased heart rate and stroke volume.
• Air enters through the nostrils into the nasal cavities where it warms up and moistens.
• Cardiac output = Heart Rate x Stroke Volume