Respiratory system

  • Role of oxygen 

  • Cellular respiration for making ATP 

  • Oxygen concentration and pressure in air 

  • Higher pressure (and more oxygen concentration) at lower altitudes 

  • Ventilation vs. Perfusion 

  • Ventilation: External respiration between the environment and blood requiring movement of air/water across respiratory organs 

  • Perfusion: internal respiration between blood and tissues requiring the pumping of blood through capillaries 

  • Factors that increase gas exchange 

  • Thin respiratory surface, increased surface area of respiratory surface, moderate moisture, and increased movement of material across respiratory surface  

  • Muscles of inhalation and exhalation 

  • During inhalation:  

  • External intercostals and diaphragm contract 

  • During exhalation: 

  • Internal intercostals contract, abdominal organs recoil to push diaphragm up, and positive pressure is created to force air out 

  • During exercise: 

  • Lungs expand more to get more oxygen in 

  • Pectoralis minor pulls ribs upward and sternocleidomastoid elevates the sternum. 

  • Roles of nasal conchae 

  • Cleans, warms, and humidifies air 

  • Function of the larynx 

  • The larynx is a cartilaginous structure inferior to the laryngopharynx that connects the pharynx to the trachea and helps regulate the volume of air that enters and leaves the lungs. The structure of the larynx is formed by several pieces of cartilage. Three large cartilage pieces-the thyroid cartilage (anterior), epiglottis (superior), and cricoid cartilage (inferior)-form the major structure of the larynx. 

  • The act of swallowing causes the pharynx and larynx to lift upward, allowing the pharynx to expand and the epiglottis of the larynx to swing downward, closing the opening to the trachea. 

  • Structure and function of the trachea 

  • Mucus and cilia trap particles and move them up to the pharynx 

  • Left vs. right lung 

  • The right lung is shorter and wider than the left lung, and the left lung occupies a smaller volume than the right. The cardiac notch is an indentation on the surface of the left lung, and it allows space for the heart. The right lung has 3 lobes while the left lung has only 2 (need space for the heart). 

  • Bronchi vs. Bronchioles 

  • Bronchi (the main airways) branch off into smaller bronchioles 

  • Bronchi surrounded by cartilage and bronchioles surrounded by muscle 

  • Structure and function of alveoli 

  • Where gas exchange occurs 

  • Stem from alveolar ducts and connect to neighboring alveoli with pores to maintain pressure 

  • Types of cells in the alveoli and roles 

  • Type 1: simple squamous for gas exchange 

  • Type 2: Produce surfactants (detergents) to decrease surface tension 

  • Macrophages: Remove debris and pathogens 

  • Path of air from nose to alveoli 

  • Nostrils, nasal cavity (conchae warms, humidifies, and cleans air), pharynx, larynx, trachea, left/right primary bronchi, 5 bronchi branches, bronchioles (many branches), alveoli (where gas exchange happens) 

  • How gases are exchanged 

  • Simple diffusion where oxygen moves from alveoli into capillaries and carbon dioxide moves from capillaries into alveoli 

  • How are gases transported in the blood? 

  • Oxygen bound to hemoglobin, (capillaries decrease in oxygen, lungs increase in oxygen), heme binds oxygen and moves through the body, exits via diffusion along its partial pressure gradient (aided and kicked out via heat, decreased pH, and binding carbon dioxide) 

  • Factors affecting oxygen binding to heme 

  • Temperature, pH, and CO2 

  • How CO2 is transported in the blood 

  • Binds globin in hemoglobin 

  • CO2 binding and release 

  • How carbonic anhydrase works 

  • An enzyme that RBC’s use to convert CO2 to carbonic acid (H2CO3)