The Respiratory System – Key Vocabulary

Vocabulary flashcards summarizing structures, processes, and diseases associated with the human respiratory system.

Respiratory system

Body system that supplies oxygen to cells and removes carbon dioxide waste.

Breathing

Physical process of inhalation and exhalation that moves air in and out of the lungs.

Gaseous exchange

Diffusion-based on the swapping of Oxygen and Carbon Dioxide between alveoli and blood.

Cellular respiration

Chemical breakdown of glucose using oxygen to release energy, producing Carbon Dioxide and water.

Inhalation

Phase of breathing in which the diaphragm contracts and air is drawn into the lungs.

Exhalation

Phase of breathing out in which the diaphragm relaxes and air is forced from the lungs.

Diffusion

Movement of molecules from a region of high concentration to low concentration across a membrane.

Selective permeable membrane

Barrier that allows certain molecules (e.g., gases) to pass while restricting others.

Nose (nostrils)

Primary entry point for air; warms, filters, and moistens incoming air.

Nasal cavity

Internal space behind the nose lined with cilia and mucus to cleanse inhaled air.

Cilia

Fine hairs in the nasal passages that trap dust and pathogens.

Mucus

Sticky secretion that humidifies air and captures particles in the respiratory tract.

Mouth

Secondary pathway for breathing, typically used when nasal passages are blocked.

Windpipe (trachea)

Cartilage-reinforced airway tube that conducts air from nasal cavities to bronchi.

Cricoid cartilage

Ring of cartilage that helps keep the trachea open.

Bronchus (plural: bronchi)

One of two main tubes branching from the trachea into each lung.

Bronchiole

Narrower airway branches within the lungs that lead to alveolar sacs.

Infundibulum

Small lung sac at the end of a bronchiole that holds clusters of alveoli.

Alveolus (plural: alveoli)

Microscopic air sac with thin walls where gaseous exchange occurs.

Capillary

Tiny blood vessel surrounding alveoli for gas exchange with blood.

Lungs

Pair of spongy, elastic organs in the chest cavity responsible for gas exchange.

Diaphragm

Dome-shaped muscle below the lungs that drives ventilation by contracting and relaxing.

Chest cavity

Thoracic space enclosed by ribcage, spine, and sternum that houses lungs and heart.

Asthma

Allergy-related inflammation and narrowing of airways causing wheezing and breathlessness.

Cause of asthma

Hereditary and can be influenced by factors such as the environment

Cause of lung cancer and bronchitis

Mostly caused by lung cancer and air pollution

Lung cancer

Uncontrolled cell growth in lung tissue forming tumors that impair oxygen uptake

Bronchitis

Inflammation of bronchial lining with excess mucus, leading to cough and airway congestion.

Bronchitis symptoms

Wheezing and shortness of breath

Tuberculosis (TB)

Contagious bacterial infection that destroys lung tissue and causes persistent coughing, sometimes with blood.

Cause of Tuberculosis (TB)

Bacteria growth (is contagious)

Pneumonia

Lung infection in which alveoli fill with fluid, hindering gas exchange.

Causes of pneumonia

Primarily caused by bacteria, fungi and viruses

Emphysema

Disease where alveolar walls break down, reducing lung elasticity and gas exchange efficiency.

Causes emphysema

Long term exposure to airborne irritants, with smoking being the most common cause)

Asbestosis

Chronic lung condition from inhaled asbestos fibers that scar and stiffen lung tissue.