Marieb_ch13a Respiratory

Respiratory System

The organ system responsible for gas exchange between the blood and the external environment.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Respiratory System

The organ system responsible for gas exchange between the blood and the external environment.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Trachea

The windpipe that connects the larynx to the bronchi.

Bronchi

The major air passages that branch from the trachea into the lungs.

Nasal Cavity

The space behind the nose that is lined with mucosa; responsible for filtering and warming the inhaled air.

Pharynx

Muscular passage that connects the nasal cavity to the larynx; has three regions: nasopharynx, oropharynx, and laryngopharynx.

Larynx

The voice box that routes air and food into the respective channels and is responsible for speech.

Pleura

Membranes surrounding the lungs; includes visceral pleura and parietal pleura.

Vital Capacity

The total amount of exchangeable air in the lungs.

Intrapleural Pressure

The pressure within the pleural cavity, which is typically negative to keep the lungs inflated.

Surfactant

A substance that coats the alveolar surfaces to reduce surface tension and prevent collapse.

Pulmonary Ventilation

The process of moving air in and out of the lungs.

External Respiration

Gas exchange between pulmonary blood and alveoli.

Internal Respiration

Gas exchange between blood and tissue cells.

Inspiratory Reserve Volume (IRV)

The amount of air that can be taken in forcibly beyond the tidal volume.

Expiratory Reserve Volume (ERV)

The volume of air that can be forcibly exhaled after a normal exhalation.

Residual Volume

The air that remains in the lungs after forced expiration.

Olfactory Receptors

Sensory receptors for smell located in the nasal cavity.

Epiglottis

The flap of elastic cartilage that covers the larynx during swallowing.

Ciliated Mucosa

A lining of the trachea that helps in cleaning the air by moving mucus out of the lungs.

Dead Space Volume

Air that remains in the conducting zone and does not participate in gas exchange.

Macrophages

Immune cells in the alveoli that help protect the lungs by engulfing pathogens and debris.