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Module 15 in the Syllabus

The Respiratory System Images
Image gallery for study with links to larger teaching JPEGs for classroom presentation

Question Drill for The Respiratory System
Conceptual Vocabulary Self-Test

Basic Terms Crossword Puzzle

Basic Puzzle Solution

Conceptual Vocabulary
Respiratory systemThe respiratory system consists of the airways, the lungs, and the muscles that mediate the movement of air into and out of the body.
Respiratory tractIn humans the respiratory tract is the part of the anatomy that has to do with the process of respiration.
LarynxThe larynx, colloquially known as the voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production.
Vertebrate tracheaThe trachea, or windpipe, is a tube that extends from the larynx to the primary bronchi.
Thoracic diaphragmThe diaphragm is a sheet of muscle extending across the bottom of the ribcage which separates the thoracic cavity from the abdominal cavity and performs an important function in respiration.
NostrilA nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening.
BronchusA bronchus is a caliber of airway in the respiratory tract that conducts air into the lungs.
Right main bronchusThe right main bronchus is wider, shorter, and more vertical in direction than the left, entering the right lung nearly opposite the fifth thoracic vertebra.
Left main bronchusThe left main bronchus is smaller in caliber but longer than the right, entering the root of the left lung opposite the sixth thoracic vertebra.
Tertiary bronchusThe tertiary bronchi arise from the secondary bronchi.
Primary bronchioleThe primary bronchioles arise from the tertiary bronchi.
InhalationInhalation, also known as inspiration, is the movement of air from the external environment, through the airways, into the alveoli during breathing.
ExhalationExhalation, or expiration, is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing.
Pulmonary circulationPulmonary circulation is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
Terminal bronchioleA terminal bronchiole is a bronchiole at the end of the conducting zone.
Alveolar ductAlveolar ducts are the tiny end tubules of the branching airways that fill the lungs.
Vital capacityVital capacity is the maximum volume of air that a person can exhale after maximum inhalation.
Functional residual capacityFunctional residual capacity is the volume of air present in the lungs at the end of passive expiration.
Dead spaceDead space is air that is inhaled by the body in breathing, but does not partake in gas exchange.
Pulmonary surfactantPulmonary surfactant is a surface-active lipoprotein complex formed by type II alveolar cells which reduces surface tension in the air water interface within alveoli.
Nasal cavityThe nasal cavity, or nasal fossa, is a large air-filled space above and behind the nose in the middle of the face.
Bronchopulmonary segmentEach of the tertiary bronchi serves a specific bronchopulmonary segment, and each of these segments have their own artery.
Respiratory bronchioleA respiratory bronchiole is an airway at the beginning of the respiratory zone.
VentilationVentilation rate is the rate at which gas enters or leaves the lung.
Pulmonary stretch receptorsPulmonary stretch receptors are mechanoreceptors found in the lungs, which when the lung expands, initate the Hering-Breuer reflex, reducing the respiratory rate.
Hering-Breuer reflexThe Hering-Breuer reflex is a reflex triggered to prevent overinflation of the lungs by pulmonary stretch receptors present in the smooth muscle of the airways which respond to excessive stretching of the lung.
Clara cellClara cells are non-mucous and non-ciliated secretory cells found in the primary bronchioles of the lungs.
Alveolar-capillary barrierThe alveolar-capillary barrier exists in the gas exchanging region of the lungs, preventing air bubbles from forming in the blood and preventing blood from entering the alveoli.
Advanced terms that may appear in context in MCAT passages
Respiratory minute volumeRespiratory minute volume is the volume of air which can be inhaled or exhaled from a person's lungs in sixty seconds.
Lamellar bodiesLamellar bodies, or keratinosomes, are secretory organelles found in type II pneumocytes which deliver pulmonary surfactant after being released from the cell.
SpirometrySpirometry is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount and/or speed of air that can be inhaled and exhaled.
RespirometerA respirometer is a device used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and carbon dioxide.
DipalmitoylphosphatidylcholineDipalmitoylphosphatidylcholine (DPPC) is a phospholipid and the major constituent of pulmonary surfactant.
Pulmonary complianceCompliance is the ability of the lungs to stretch in a change in volume relative to an applied change in pressure.
Respiratory quotientThe respiratory quotient is a unitless number used in calculations of basal metabolic rate when estimated from carbon dioxide production.
Diffusion capacityDiffusion capacity is a measurement of the lung's ability to transfer gases.

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