Act Of Breathing In

Can you explain breathing.

Expert Answers
ako6777 eNotes educator| Certified Educator

Breathing is the process by which we take in oxygen and release the waste product called carbon dioxide.  Inhaling occurs when the diaphragm is contracted and air is sucked into the lungs.  This occurs due to the negative pressure in the lungs.  When we exhale, it is due to the relaxing of the diaphragm muscles. As these muscles compress the lungs, lung volume decreases and lung pressure increases.  This forces the air and carbon dioxide out of the lungs.

Breathing requires gas exchange.  This is how oxygen gets into the blood and carbon dioxide is removed.  It occurs in the lungs within the alveoli.  The alveoli are tiny sacs that process the exchange.

Breathing is controlled by the brain stem located at the base of the brain. It is unconsciously controlled although we can consciously control it.  Some examples of conscience control is holding our breath during swimming and deep breathing during yoga exercises.

besure77 eNotes educator| Certified Educator

Breathing occurs automatically and each day a healthy person breathes about 20,000 times. By the time this person reaches the age of 70, they will have taken over 600 million breaths.

Here is a simplified version of the breathing process:

  1. When you breath in air through your nose and mouth, you breathing in air that is rich in oxygen.
  2. The air goes through the windpipe and enters the lungs.
  3. Alveoli are tiny air sacs in the lungs. Their purpose in to transfer the oxygen to the blood.
  4. While the oxygen is being absorbed into the bloodstream, carbon dioxide is removed from the bloodstream and transported to the tiny sacs.
  5. This is when you breath out and release carbon dioxide.
dano7744 eNotes educator| Certified Educator

The act of breathing involves exchange of gases oxygen and carbon dioxide. You breathe in your mouth or nose, air (oxygen) travels down the trachea(windpipe) which splits(bifurcates) into the right and left lung. At the base of each lung are capillary beds called alveoli. Gases that are carried by the blood( oxygen O2 and carbon dioxide CO2) are exchanged here in the alveolus(plural). Your lungs have thousands of alveoli. When you take in a breath is called inspiration and when you exhale is called exhalation. The act of breathing is under the control of the ANS(autonomic nervous system). The vagus nerve(tenth cranial nerve)innervate the diaphragm, a muscle right under the rib cage 

krishna-agrawala | Student

Most animals need a continuous supply of oxygen to survive. The process that involves how an animal takes oxygen from its environment and gives off carbon dioxide is known as breathing. Land animal obtain their supply of oxygen from air while those living in water get it from water. Many land animal including humans breathe through lungs. Most aquatic animals use lungs to get their supply of oxygen. Described below is the the process of breathing in humans in greater detail.

Lungs, the chief organs of breathing in humans, are elastic structures in the chest cavity.  Each lung contains millions of small air chambers, or sacs, called alveoli. Other structures important in breathing are the chest wall and the diaphragm.  which is a dome-shaped sheet of muscle that separates the chest cavity from the abdomen.

Air enters and leaves the body through the nose and the mouth and reaches the lungs through pharynx , larynx, and trachea.

Breathing consists of two acts of two sub processes of breathing in (inspiration or inhalation) and breathing out (expiration or exhalation)).  During inhalation, air from the atmosphere is drawn into the lungs, and  during exhalation, air is expelled from the lungs. 

Inspiration is caused by contraction of  the diaphragm and the muscles of chest wall, making  the chest cavity longer and wider.  The expansion of the lungs creates reduces air pressure in the alveoli, drawing fresh air into the lungs.

Expiration results when the diaphragm and other muscles relax, causing the lungs to retract increasing the pressure of the gas in the alveoli to become greater than the atmospheric pressure.  As a result, gas flows out of the lungs.

Oxygen and carbon dioxide are exchanged between the lungs and the blood through the thin walls of capillaries in the alveoli.  Blood entering these capillaries is low in oxygen and high in carbon dioxide.  Oxygen from the air inhaled passes into the blood, while carbon dioxide carried by blood is released into the alveoli.

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