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×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 (VT)

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.