The processes of inspiration (breathing in) and expiration (breathing out) are vital for providing oxygen to tissues and removing carbon dioxide from the body. Inspiration occurs via active contraction of muscles – such as the diaphragm – whereas expiration tends to be passive, unless it is forced.

What muscles are involved in inspiration and expiration?

The rib cage muscles, including the intercostals, the parasternals, the scalene and the neck muscles, mostly act on the upper part of the rib cage (pulmonary rib cage) and are both inspiratory and expiratory. The abdominal muscles act on the abdomen and the abdominal rib cage and are expiratory.

What muscles are involved in expiration?

During active expiration, the most important muscles are those of the abdominal wall (including the rectus abdominus, internal and external obliques, and transversus abdominus ), which drive intra-abdominal pressure up when they contract, and thus push up the diaphragm, raising pleural pressure, which raises alveolar

What is inspiration and expiration?

Pulmonary ventilation comprises two major steps: inspiration and expiration. Inspiration is the process that causes air to enter the lungs, and expiration is the process that causes air to leave the lungs (Figure 3). A respiratory cycle is one sequence of inspiration and expiration.

What muscles are involved in inhalation and exhalation?

Inhalation is accomplished when the diaphragm contracts and flattens, moving the floor of the thorax inferiorly, and the intercostal muscles lift the rib cage up and outward. Exhalation is gen- erally a passive event, except in cases of forced exhalation.

Which muscles are used for inspiration quizlet?

Terms in this set (23)

• Diaphragm. -Primary muscle of inspiration which separates the thoracic and abdominal cavities.
• Attachments of the Diaphragm.
• Innervations of diaphragm.
• Contraction of diaphragm.
• Accessory muscles of inspiration.
• Accessory muscles of expiration.
• External intercostals.
• Levatus costarum brevis.

Which muscles are involved in forceful inspiration and shoulder girdle movements?

The pectoralis minor muscle is a small triangular shaped muscle that lies deep to pectoralis major muscle and passes as three muscular slips from the thoracic wall (ribs III to V) to the coracoid process of the scapula. Pectoralis minor draws the scapula forward and downward, and raises the ribs in forced inspiration.

Which muscles are important for inspiration?

Respiratory muscles The diaphragm, a dome-shaped sheet of muscle that separates the chest cavity from the abdomen, is the most important muscle used for breathing in (called inhalation or inspiration). The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine.

How does inspiration and expiration occur?

When the air pressure within the alveolar spaces falls below atmospheric pressure, air enters the lungs (inspiration), provided the larynx is open; when the air pressure within the alveoli exceeds atmospheric pressure, air is blown from the lungs (expiration).

Which muscles are involved in expiration Class 10?

Expiration occurs when the diaphragm and the intercostal muscles relax.

What are the accessory muscles of inspiration?

These accessory muscles of inspiration include the sternocleidomastoid, pectoralis minor and major, serratus anterior, latissimus dorsi, and serratus posterior superior muscles. Expiration, in contrast, is a passive process produced by elastic recoil of the thoracic cage.

What happens to intercostal muscles during inspiration?

During inspiration, the diaphragm and the external intercostal muscles contract causing an increase in the thoracic cavity volume. The contraction of the diaphragm accounts for approximately 75% of the air movement during normal breathing.

What muscles are used during forced exhalation?

During forced exhalation, internal intercostal muscles which lower the rib cage and decrease thoracic volume while the abdominal muscles push up on the diaphragm which causes the thoracic cavity to contract.