The partial pressure of oxygen is low inside the tissue while that of the carbon dioxide is high when compared to the blood. Therefore, oxygen diffuses into the tissue and carbon dioxide diffuses into the blood. Ventilation: Ventilation refers to the provision of fresh air into the lungs.
Respiration: Respiration refers to the gas exchange between the body and the external environment. Ventilation: Ventilation is the first event of respiration. Respiration: Respiration is the taking up of oxygen by the red blood cells. Ventilation: Ventilation is breathing, which takes air into the lungs. Respiration: Respiration is the exchange of oxygen and carbon dioxide between blood and the atmospheric air.
Ventilation: Ventilation is carried out by lungs. Respiration: Respiration occurs in the alveoli and walls of blood capillaries. Ventilation: All gases in the atmospheric air are taken into the lungs during ventilation. Respiration: Oxygen and carbon dioxide are involved in the respiration.
Ventilation: Ventilation is a physical process. Respiration: Respiration is a chemical process. Ventilation: Ventilation is a voluntary action. Respiration: Respiration is an involuntary action. Ventilation: Inspiration and expiration are the two events of ventilation. Respiration: Internal and external respiration are the two events of respiration. Ventilation: Ventilation occurs based on the pressure differences of air between lungs and the atmosphere. A ventilation can only take place if the brainstem, cranial and associated peripheral nerves, the diaphragm, intercostal musculature and lungs are all functional.
Combining the function of all these structures, the pulmonary ventilation mechanism establishes two gas pressure gradients. One, in which the pressure within the alveoli is lower than atmospheric pressure — this produces inhalation. The other, in which the pressure in the alveoli is higher than atmospheric pressure — this produces exhalation.
These necessary changes in intrapulmonary pressure occur because of changes in lung volume. So, how does the lung volume change? Quite simply, it is a combination of muscle contractions stimulated by the central nervous system , and the movement of a serous membrane within the thorax called the pleura.
The pleura is made of two layers: a parietal layer that lines the inside of the thorax and a visceral layer that covers the lungs and adjoining structures blood vessels, bronchi, and nerves. Between the visceral and parietal layers is a small, fluid-filled space, called the pleural cavity. The initiation of ventilation begins with the brainstem, where impulses action potentials generate within the medulla oblongata, then travel distally within the spinal cord.
The impulse traverses individually through cervical nerves three, four and five until just above the clavicle. Here, the three cervical nerves merge into one large nerve called the phrenic nerve, which attaches distally to the diaphragm. Imagine these two nerves resembling a pair of suspenders on the anterior chest. The delivered impulse from the phrenic nerve initiates diaphragm contraction.
The intercostal muscles are a group of intrinsic chest wall muscles occupying the intercostal spaces.
They are arranged separately in three distinct layers external intercostal muscles, internal intercostal muscles, and innermost intercostal muscles. The intercostal nerves that stimulate these muscles originate from the spinal cord thoracic nerves Inhalation is initiated as the dome-shaped diaphragm is stimulated. As it contracts and flattens, the thorax expands inferiorly.
The internal and innermost intercostal muscles relax, while the external intercostal muscles contract from stimulus by the thoracic nerves. This produces an upward and outward movement of the ribs similar to the movement of a bucket handle , and the sternum similar to when pulling upward on a handle of a water pump. The fluid in the pleural cavity acts like glue, adhering the thorax to the lungs. Hence, as the thorax expands vertically and laterally, the parietal layer drags the visceral layer along with it, causing the lungs to expand.
Adequate expansion of the lungs results in a decreased pressure within the alveoli. Therefore, when the alveolar pressure drops below atmospheric pressure, air rushes into the lungs. Remember, inhalation requires a stimulus initiated from the central nervous system. Think of it like turning on a light.
The light stays unlit until you flip a switch CNS , releasing electricity and stimulating the components of the light bulb.
As long as the switch is on and there is an impulse, the light stays lit. However, if you turn off the switch, the stimulus ceases, and the light shuts down. Exhalation is akin to turning off the switch, so to speak. Thoracic stretch receptors constantly monitor chest expansion. Consequently, the diaphragm and the external intercostal muscles relax, decreasing the thoracic volume — like letting air out of a balloon.
Assisting with this passive process, the internal and innermost intercostal muscles are stimulated. Their contraction pulls the ribcage and attached pleura further downward and inward, compressing the lungs and increasing the air pressure within the alveoli. Once the alveolar pressure exceeds the atmospheric pressure, air moves out of the lungs. That is all there is to it — simple, right? Adults normally ventilate between 12 to 20 times per minute, thanks to the autonomic nervous system.
In general terms, respiration is a chemical process whereas breathing is a chemical process. Both are inter-related but their mechanisms vary. Below we will have a look at the different characteristics between breathing and respiration. Comparison Basis. Breathing is the process of inhaling oxygen from the environment and exhaling carbon dioxide back to it with the help of the lungs.
It is a process where glucose and oxygen are broken down to produce energy which is used for cellular activities. It is a biophysical voluntary process which happens in two stages i inhalation and ii exhalation.
It is a biochemical involuntary process which takes place through i glycolysis ii Krebs cycle. Where does it take place? It takes place in the lungs or gills. It takes place in cells. Energy production. No energy is produced in this process. Energy is produced in the form of ATP. Cellular activity. Breathing is an extracellular process. Respiration is an intracellular process.
Enzymes used. There are no enzymes used in this process. Many enzymes play a major role in respiration. Organs or systems associated:.
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