Inspiratory muscles relax (diaphragm rises; rib cage descends due to recoil of costal cartilages). Elastic lungs recoil passively; intrapulmonary volume decreases. Intrapulmonary pressure rises (to +1 mm Hg). Air (gases) flows out of lungs down its pressure gradient until intrapulmonary pressure is 0.
In expiration,the external intercostals muscles are relaxed and internal intercostals muscles are contracted. In inspiration,rib cage moves forward and outward. In expiration,the rib cage moves downward and inward. In inspiration,the diaphragm contracts and flattens.

What is the correct sequence of events for inhalation?

The respiratory route of air in the respiratory tract is: Nostrils → nasal cavity →Pharynx → Larynx →Trachea → Bronchi → Bronchioles → Alveoli or air sacs.

What are the 4 events that cause expiration?

Terms in this set (4)

• The diaphragm and external respiratory muscles relax.
• Elastic tissues of the lungs, stretched during inspiration, suddenly recoil, and surface tension pulls in on alveolar walls.
• Tissues recoiling around the lungs increase the intra-alveolar pressure.
• Air is forced out of the lungs.

What is the process of inspiration and expiration?

When the lungs inhale, the diaphragm contracts and pulls downward. As a result, air rushes in and fills the lungs. The second phase is called expiration, or exhaling. When the lungs exhale, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases.

What are the steps of expiration?

Terms in this set (5)

• Respiration center in the medulla oblongota stops sending nerve impulses to diaphragm & rib cage.
• Diaphragm & ribcage relax.
• Decreased size of thoracic cavity.
• Elastic lungs recoil.
• Air is pushed out.

What is the correct passage of air during inspiration?

Explanation: The correct sequence of passage of air during inspiration is Pharynx → Larynx → Trachea → Bronchi → Alveoli.

Which is the correct sequence for the path of oxygen through the respiratory system?

Pathway of air: nasal cavities (or oral cavity) > pharynx > trachea > primary bronchi (right & left) > secondary bronchi > tertiary bronchi > bronchioles > alveoli (site of gas exchange)

Which of the following sequence is correct to initiate inspiration?

(i) The contraction of external intercostal muscles raises the ribs and sternum. (ii) Volume of thorax increases in the dorso-ventral axis. (iii) Intrapulmonary pressure decreases. (iv) Diaphragm contraction.

Which event does occur during inspiration?

Contraction of diaphragm takes place and it moves down. This downward movement of the diaphragm causes less intrapulmonary pressure than the atmosphere. Simultaneously, the external intercostal muscles also contract and cause the ribcage to be able to move outward.

What conditions are correct for inspiration?

In order for inspiration to occur, the thoracic cavity must expand. The expansion of the thoracic cavity directly influences the capacity of the lungs to expand. If the tissues of the thoracic wall are not very compliant, it will be difficult to expand the thorax to increase the size of the lungs.

What is the order of airflow during inhalation?

When you inhale through your nose or mouth, air travels down the pharynx (back of the throat), passes through your larynx (voice box) and into your trachea (windpipe). Your trachea is divided into 2 air passages called bronchial tubes. One bronchial tube leads to the left lung, the other to the right lung.

How is inspiration and expiration accomplished in human beings?

During inspiration or inhalation, the diaphragm contracts and from dome shape it becomes flat and is moved downwards. During expiration or exhalation, the diaphragm becomes dome-shaped and is back to its relaxed position. The intercoastal muscles relax. This decreases the volume of the thoracic cavity.

How does the brain control inspiration and expiration?

The dorsal respiratory group (nucleus tractus solitarius) controls mostly inspiratory movements and their timing. The medulla sends signals to the muscles that initiate inspiration and expiration and controls nonrespiratory air movement reflexes, like coughing and sneezing.

Why is inspiration an active process?

Inspiration is an active process whereas expiration is a passive process. Inspiration occurs when the muscles of the diaphragm contract to increase the overall volume of the thoracic cavity. As the muscles use energy for contraction, inspiration is called active process.

What is the process of exhalation?

Exhalation: When you breathe out, or exhale, your diaphragm relaxes and moves up into your chest cavity. As the space in your chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out your nose or mouth.