Chapter 8 EMT Key Terms

Aerobic Metabolism: The process of producing energy (ATP) in cells using oxygen.

Afterload: The resistance the heart must overcome to eject blood during systole.

Airway Resistance: The opposition to airflow within the airways, affecting breathing.

Alveolar Ventilation: The exchange of gas between the alveoli and the blood, excluding dead space ventilation.

Alveoli: Tiny air sacs in the lungs where gas exchange occurs.

Anaerobic Metabolism: Energy production in cells without oxygen, resulting in lactic acid.

Baroreceptors: Pressure-sensitive sensors in blood vessels that regulate blood pressure.

Boyle’s Law: A principle stating that pressure and volume of a gas are inversely proportional (at constant temperature).

Bronchi: The main air passages that branch off from the trachea into the lungs.

Bronchioles: Smaller airways that branch from the bronchi and lead to the alveoli.

Cardiac Output: The volume of blood the heart pumps per minute (stroke volume × heart rate).

Carina: The point where the trachea divides into the right and left main bronchi.

Central Chemoreceptors: Sensors in the brainstem that respond to changes in CO2 and pH levels in the blood.

Chemoreceptors: Sensors that detect changes in blood oxygen, carbon dioxide, and pH.

Compliance: The ability of the lungs or vessels to expand and contract with changes in pressure.

Dead Air Space: Air that fills the respiratory passages but does not participate in gas exchange.

Deoxyhemoglobin: Hemoglobin that is not bound to oxygen.

Dorsal Respiratory Group (DRG): A group of neurons in the brainstem that controls basic breathing rhythms.

Epiglottis: A flap of tissue that prevents food from entering the airway during swallowing.

Frank-Starling Law of the Heart: The principle that stroke volume increases with the stretch of the heart muscle during filling.

Frequency of Ventilation (f): The number of breaths taken per minute.

Glycolysis: The breakdown of glucose into pyruvate for energy, occurring in the cytoplasm.

Hydrostatic Pressure: The pressure exerted by a fluid due to its weight, influencing capillary filtration.

Irritant Receptors: Sensors in the airway that trigger coughing or bronchoconstriction in response to irritants.

J-Receptors: Sensors in the lungs that respond to fluid buildup, triggering rapid, shallow breathing.

Larynx: The voice box, involved in sound production and protecting the airway.

Laryngeal Spasm: Involuntary closure of the vocal cords, obstructing airflow.

Microcirculation: The circulation of blood through the smallest blood vessels, including capillaries.

Minute Ventilation: The total volume of air moved in or out of the lungs per minute (VT×fVT×f).

Minute Volume: Synonymous with minute ventilation; the total air moved per minute.

Nasopharynx: The upper part of the pharynx behind the nose, part of the airway.

Oropharynx: The part of the pharynx behind the mouth, part of the airway.

Oxyhemoglobin: Hemoglobin bound to oxygen.

Patent Airway: An airway that is open and unobstructed.

Perfusion: The delivery of oxygen and nutrients to tissues through the blood.

Peripheral Chemoreceptors: Sensors in the carotid and aortic bodies that respond to low oxygen levels.

Plasma Oncotic Pressure: The pressure exerted by plasma proteins to pull water into the circulatory system.

Pontine Respiratory Center: A brainstem region that regulates the rhythm of breathing.

Preload: The amount of blood in the ventricles before contraction, influencing stroke volume.

Respiratory Control Centers: Brainstem areas (medulla and pons) that regulate breathing.

Stretch Receptors: Sensors in the lungs that detect changes in lung volume and prevent over-inflation.

Stroke Volume: The amount of blood ejected by the heart in one contraction.

Systemic Vascular Resistance (SVR): The resistance blood encounters in systemic circulation.

Tidal Volume (VTVT): The volume of air inhaled or exhaled in a single breath.

Trachea: The windpipe, connecting the larynx to the bronchi.

Ventilation: The movement of air into and out of the lungs.

Ventilation/Perfusion (V/Q) Ratio: The balance between air reaching the alveoli (ventilation) and blood flow (perfusion).

Ventral Respiratory Group (VRG): A brainstem region that controls forced breathing.