Ramapo College of New Jersey 7

Alveolus (Alveoli): Tiny sacs at the end of the bronchioles where gas exchange occurs.
- Gas Exchange: Oxygen is taken in and carbon dioxide (CO2) is expelled.
Bronchioles: Small airways in the lungs that transport air to the alveoli.
- Function: Air or oxygen inhaled passes through bronchioles to reach alveoli.

Diaphragm: Dome-shaped muscle located below the lungs, plays a critical role in respiration.
- Importance: Essential for breathing; if it stops working, the patient can die immediately.
Intercostal Muscles:
- Internal Intercostals: Muscles located inside the rib cage that assist in expiration.
- External Intercostals: Muscles located outside the rib cage that help in inspiration.
- Note: If these muscle groups fail, breathing can persist due to diaphragm activity, but death occurs if the diaphragm fails.

Gills: Organs that allow aquatic animals (e.g., fish, amphibians) to breathe by exchanging gases with water.
- Function: Similar to lungs; designed to extract oxygen from water.

Pharynx: Tube-like structure serving as a passage for air to enter the lungs.

Spiracles: Openings in the exoskeleton of insects for air entry into the trachea, facilitating direct gas exchange with tissues.
- Located in the thorax and abdomen of insects, allowing air into the tracheal system.
Trachea: A membranous tube through which air is inspired and expired.
- Tracheal System: A network of tiny tubes that transport oxygen directly and expel carbon dioxide in insects.

Aerobic Metabolism: The process of generating energy (ATP) from food using oxygen.
- Waste Product: Carbon dioxide, which must be expelled to maintain acid-base balance in the body.
Diffusion: Movement of molecules from regions of high concentration to low concentration; how gas exchange occurs in small animals.

Cutaneous Respiration: Exchange of gases through the skin (e.g., salamanders).
Hemocyanin: A protein found in blood of arthropods and mollusks that binds oxygen, acting as a respiratory pigment.

Lamellae: Thin folds from gill filaments containing capillaries; enhances the surface area for gas exchange.
Operculum: A protective covering over gills made of bones/muscles.
Ram Ventilation: A method where fast-swimming fish (e.g., sharks, tuna) swim with mouths open for continuous water flow over gills.
- Unique Adaptation: Half of the brain sleeps while the fish continues to breathe.

Structure: In mammals, trachea divides into left and right bronchi, leading into smaller bronchioles and ending in alveoli.
- Additional Respiratory Structures: Lungs; the diaphragm; and intercostal muscles assist in ventilation.

Spirometer: Instrument used to measure lung capacity and respiratory volumes.
- Vital Capacity: Maximum air exhaled after full inhalation.
- Residual Volume: Amount of air remaining in lungs after maximum exhalation.
- Tidal Volume: Volume of air inhaled and exhaled in a normal breathing cycle (approximately 500ml).
- Inspiratory Reserve Volume: Additional volume that can be inhaled with maximum effort.
- Expiratory Reserve Volume: Maximum amount of air that can be exhaled forcefully.
- Dead Space: Volume of air that does not participate in gas exchange (about 50ml).

Maintain a thorough understanding of definitions, processes, and functions of respiratory organs across different species.
Importance of airflow in alveoli for gas exchange crucial for all animals.