Respiratory System Quiz Review

Respiratory System Quiz Review

• Conducting Passageways:
  • Nose: Entry point for the respiratory system.
  • Pharynx: Throat; common passage for air and food. Contracts during swallowing to close the epiglottis (prevents food from entering the airway).
  • Larynx: Voice box; epiglottis opens to allow air passage. Contains vocal cords.
  • Trachea: Windpipe; composed of cartilage rings and ciliated pseudostratified epithelium.
  • Bronchi (Right/Left): Branches from the trachea; carry air to the lungs.
  • Bronchioles: Smaller branches leading to alveoli.
  • Cilia: Hair-like structures that move mucus and trapped particles away from the lungs.
  • Mucus: Filters and traps particles.
  • Ciliated Mucosae: Lines the trachea; cilia move mucus upward.
  • Alveoli: Tiny air sacs where gas exchange occurs.
  • Epiglottis: Flap of cartilage that covers the trachea during swallowing.

Mechanics of Breathing

• Boyle's Law: Inverse relationship between volume and pressure (increase volume, decrease pressure). Air moves from high to low pressure.
• Diaphragm: Muscle below the lungs; contracts during inhalation to increase thoracic volume.
• External Intercostals: Muscles between ribs; elevate rib cage during inhalation, increasing thoracic volume.
• Inhalation (Inspiration): Diaphragm and intercostal muscles contract, increasing thoracic volume. This decreases intrapulmonary pressure, causing air to enter lungs.
• Exhalation: Diaphragm and intercostal muscles relax, decreasing thoracic volume. This increases intrapulmonary pressure, causing air to leave lungs.

Volumes and Capacities

• Residual Volume: Air remaining in lungs after maximal exhalation.
• Tidal Volume: Volume of air exchanged during a normal breath.
• Inspiratory Reserve Volume: Additional air that can be inhaled after a normal breath.
• Expiratory Reserve Volume: Additional air that can be exhaled after a normal breath.
• Total Lung Capacity: Maximum amount of air the lungs can hold.

Partial Pressure of Gases & Diffusion

• Diffusion: Movement of molecules from high to low concentration.
• Total Atmospheric Pressure: Pressure exerted by the atmosphere (760 mmHg).
• Partial Pressure: Pressure exerted by a specific gas in a mixture.
• Dalton's Law: Each gas in a mixture exerts its own pressure.
• Partial Pressure (Px) and Diffusion: Greater difference in Px = faster diffusion of gases (O2 & CO2) between air and blood. Smaller gradient = slower diffusion.
• Px and Hemoglobin Affinity: Px influences how readily hemoglobin binds to oxygen (higher Px leads to higher affinity generally.)
• Factors Affecting Hemoglobin Affinity: pH (lower pH reduces), temperature (higher temperature reduces), and other factors. Hypoxia (low blood oxygen) caused by low Px gradient leads to impaired oxygen binding to hemoglobin.
• Altitude Sickness: Low oxygen at high altitudes leads to low blood oxygen and symptoms like nausea, headache, and dyspnea.

Gas Transport in the Blood

• Oxyhemoglobin: Oxygen bound to hemoglobin.
• Hemoglobin: Protein in red blood cells that carries oxygen.
• Iron: Essential component of hemoglobin; crucial for oxygen transport.
• Carbonic Acid: Weak acid formed when CO2 dissolves in water.
• Bicarbonate Ion: Ion formed from carbonic acid dissociation; important for CO2 transport.
• CO2 Loading/Unloading: Oxygen binding to hemoglobin displaces CO2 and hydrogen ions, aiding in CO2 removal from the blood.