external intercostals and the diaphragm
Breathing. These muscles are used to change the pressure in the chest so air can flow in and out of the lungs (on inspiration and expiration).
The deep thorax muscles are the deep muscles of the thorax that promotes the inspiratory phase of breathing. When breathing the diaphragm contracts, producing a negative pressure, which forces are into the lungs.
A Internal Positive Pressure aid is an artificial aid for breathing used if you have problems with your muscles or lungs.
Breathing in frogs is called positive pressure breathing because they actively push air into their lungs using the floor of their mouth. When a frog closes its nostrils and lowers its mouth, it creates a pressure difference that forces air into the lungs. This method contrasts with negative pressure breathing, which is used by mammals, where the diaphragm creates a vacuum to draw air in. In essence, frogs rely on this positive pressure mechanism to ensure efficient gas exchange.
Muscles are used for picking things up, breathing, seeing, and/or doing a physical activity, such as walking.
The diaphragm, the external intercostal and the interchondral portion of the internal intercostal muscles are the main muscles that control breathing. Other muscles are sometimes used, but only if the person has a breathing disorder or if the body needs energy very quickly.
The intercostal muscles lie between the ribs. When you exhale, these muscles contract, and in conjunction with the abdominal muscles, the lungs contract and air is forced up via a positive pressure gradient.
1. diaphragm 2. external intercostal muscles 3. internal intercostal muscles (only in forceful exhalation such as coughing not relaxed breathing)
Forced breathing, or active breathing, involves the use of additional muscles to increase the volume of air inhaled or exhaled, typically during vigorous activities or exercises. In contrast, quiet breathing, or passive breathing, relies primarily on the diaphragm and intercostal muscles, functioning without conscious effort. During forced inhalation, accessory muscles such as the sternocleidomastoid and scalene muscles are engaged, while forced exhalation may involve the abdominal muscles and internal intercostals to expel air more forcefully.
Well your heart is used for breathing it's a cardiac muscle by the way :-()
Fitness affects the pulse and breathing rate because the more your muscles are used the more they are used to the physical activity you are asking of them to do. Exercising puts a lot of pressure on your muscles and heart, if you are unfit it can make your heart work over time, increasing your heart and breathing rate.
Bourdon's tube pressure gauge cannot be used to measure negative pressure. This is because absolute pressure must be measured and the Bourdon gauge only indicates the gauge pressure.