Respiratory System

What are the functions of the respiratory system?

• supply oxygen

• eliminate carbon dioxide

• allow air to reach lungs

• exchange gas

• purify, humidify, and warm incoming air

What are the two main components of the respiratory system?

upper respiratory tract and lower respiratory tract

upper respiratory tract

organs in this tract are located outside of the chest cavity and include the nose, larynx, and pharynx

lower respiratory tract

organs of this tract are located inside of the chest cavity and include the trachea, lungs, and all segments of the bronchial tree

both food and air pass through this before reaching their destinations

pharynx

trachea

located below the larynx and is the main airway to the lungs

What are the bronchi?

two structures that branch from the trachea into each lung

diaphragm

the main respiratory muscle that contracts and relaxes to allow air into the lungs

What makes up the lung’s anatomy?

apex, base, division, bronchioles, and alveoli

apex

the narrow, superior portion of each lung just below the clavicle

base

the broad lung area that rests on the diaphragm

division

each lung is divided into lobes by fissures; the left lung has two lobes and the right has three

alveoli

microscopic balloon-shaped structures located at the end of the respiratory tree

pleural fluid

a slippery serous secretion that allows the lungs to glide easily over the thorax wall during breathing movements and causes the two pleural layers to cling together

pleura

a thin membrane that surrounds the lungs and lines the chest cavity

What is included in the respiratory zone?

includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli

What is external respiration?

gas exchange between the pulmonary blood and alveoli

What is respiratory gas transport?

when oxygen and carbon dioxide is transported to and from the lungs and tissue cells via the bloodstream

What is internal respiration?

when gas exchanges are made between blood and tissue cells in capillaries

tidal volume

normal quiet breathing; moves approx. 500 mL of air into and out of the lungs with each breath

inspiratory reserve volume

the amount of air that can be forcibly taken in on top of the tidal volume, normally between 2100 mL and 3200 mL

expiratory reserve volume

the amount of air that can be forcibly exhaled after a tidal expiration, approx. 1200 mL

residual volume

even after strenuous expiration about 1200 mL of air remain in the lungs and cannot be voluntarily expelled