Page 2: Air Quality and Sports

• Bad air quality in Beijing during the 2008 Olympic games

  • Several athletes had respiratory problems or health concerns

  • $17 billion spent on improving air quality

  • Air pollution still higher than safe levels by WHO standards

Page 3: The Respiratory System and Its Regulation

• Chapter focuses on pulmonary ventilation, anatomy of the respiratory system, and gas exchange

• Activities include studying lung structures, key events of pulmonary ventilation, gas exchange, and oxygen transport

• Regulation of pulmonary ventilation is reviewed in-depth

Page 4: Respiratory System, Part 1: Crash Course A&P #31

• Breathing is important

• Part 1 discusses bulk flow vs simple diffusion in the respiratory system

Page 5: Crash courses Respiratory System

• Part 1 and Part 2 of Crash Course A&P videos on the respiratory system

• Part 2 explains gas exchange and hyperventilation

Page 6: Content Pulmonary Ventilation

• Covers inspiration, expiration, pulmonary volumes, pulmonary diffusion, gas exchange in the alveoli, and transport of oxygen and carbon dioxide in the blood

• Also discusses gas exchange at the muscles, factors influencing oxygen delivery and uptake, carbon dioxide removal, and regulation of pulmonary ventilation

Page 9: Pulmonary Ventilation

• Four processes involved in carrying oxygen and removing carbon dioxide from tissues

• Pulmonary ventilation, pulmonary diffusion, transport of oxygen and carbon dioxide via the blood, and capillary diffusion

Page 11: Pulmonary Ventilation

• Breathing involves moving air into and out of the lungs

• Two phases: inspiration and expiration

• Anatomy includes nasal cavity, pharynx, larynx, trachea, bronchial tree, respiratory bronchioles, and alveoli

• Gas exchange starts in the alveoli

Page 14: Inspiration

• Active process involving contraction of the diaphragm and external intercostal muscles

• Increases dimensions and volume of the thoracic cage

• Decreases pressure in the lungs, allowing air to flow in

Page 15:

• Inspiration

  • Atmospheric pressure = 760 mmHg

  • Intrapulmonic pressure = 760 mmHg

  • Sternum pressure = 758 mmHg

  • Diaphragm - decreased intrapulmonic pressure

  • Ribs - decreased intrapleural pressure

  • Resting positions of the diaphragm and the thoracic cage increase during inspiration, forming a negative pressure that draws air into lungs.

Page 16:

• Inspiration

  • Boyle's gas law: pressure x volume is constant (at a constant temperature)

  • When the lungs are expanded, they have a greater volume and the air within them has more space to fill

  • The pressure within the lungs (intrapulmonary pressure) decreases

  • The intrapulmonary pressure is now less than the atmospheric pressure

  • This leads the air from the outside rushing into the lungs

Page 17:

• Inspiration

  • Pressure change in the lungs for normal breathing during rest is quite small

  • Only about 2 to 3 mmHg

  • During maximal respiratory efforts during exhaustive exercise change is way higher

  • Up to 80 - 100 mmHg

Page 18:

• Inspiration

  • During heavy exercise, inspiration is further assisted by the action of other muscles

  • the scaleni (anterior, middle, and posterior)

  • the sternocleidomastoid in the neck

  • the pectorals in the chest

  • These muscles help raise the ribs even more than during regular breathing.

Page 19:

• The Respiratory System and Its Regulation

  • Chapter covers the anatomy and functions of the respiratory system

  • Pulmonary Ventilation

  • Anatomy of the Respiratory System

  • Inspiration and Expiration

  • Pulmonary Volumes

  • Pulmonary Diffusion

  • Arterial-Venous Oxygen Difference

  • Respiratory Membrane

  • Partial Pressures of Gases

  • Gas Exchange in the Alveoli

  • Transport of Oxygen and Carbon Dioxide in the Blood

  • Factors Influencing Oxygen Delivery and Uptake

  • Carbon Dioxide Removal

  • Regulation of Pulmonary Ventilation

Page 20:

• Expiration

  • At rest: passive process

  • Inspiratory muscles and diaphragm relax

  • The elastic tissue of the lungs recoils

  • Thoracic cage returns to its original dimensions

  • This increases the pressure in the lungs and forces air out

Page 21:

• Expiration

  • Atmospheric pressure = 760 mmHg

  • Intrapulmonic pressure = 758 mmHg

  • Expiration - increased intrapulmonic pressure

  • Intrapleural pressure = 756 mmHg

  • increased intrapleural pressure = 754 mmHg

  • The dimensions of the lungs and the thoracic cage increase during inspiration, forming a negative pressure that draws air into lungs.

Page 22:

• Expiration

  • In forced breathing, expiration becomes active

  • Involving the following muscles:

    • Internal intercostal muscles actively pull the ribs down

    • Assisted by the latissimus dorsi and quadratus lumborum muscles

    • Contracting the abdominal muscles increases the intra-abdominal pressure, forcing the abdominal viscera upward against the diaphragm and accelerating its return to the domed position

Page 23:

• Expiration

  • Respiratory pump: Changes in intra-abdominal and intra-thoracic pressure that accompany forced breathing help return venous blood back to the heart

  • Intra-abdominal and intra-thoracic pressure increases, it is transmitted to the great veins—the pulmonary veins and superior and inferior venae cavae—that transport blood back to the heart.

  • When the pressure decreases, veins return to their original size and fill with blood

  • The changing pressures within the abdomen and thorax squeeze the blood in the veins, assisting its return through a milking action

Page 25:

• Content

  • Pulmonary Ventilation

    • Inspiration

    • Expiration

  • Pulmonary Volumes

  • Pulmonary Diffusion

    • Blood Flow to the Lungs at Rest

    • Respiratory Membrane

    • Partial Pressures of Gases

    • Gas Exchange in the Alveoli

  • Transport of Oxygen and carbon Dioxide in the Blood

    • Oxygen Transport

    • Carbon Dioxide Transport

  • Gas Exchange at the Muscles

    • Arterial–Venous Oxygen Difference

    • Oxygen Transport in the Muscle

    • Factors Influencing Oxygen Delivery and Uptake

    • Carbon Dioxide Removal

  • Regulation of Pulmonary Ventilation

Page 26:

• Pulmonary Volumes

  • Can be measured with a spirometry

  • A simple spirometer: Bell filled with air that is partially submerged in water

  • Tube runs from the subject's mouth under the water and emerges inside the bell, just above the water level.

  • As the person exhales, air flows down the tube into the bell, causing the bell to rise

  • Bell is attached to a pen

  • Movement is recorded on a simple rotating drum

Page 27:

• Pulmonary Volumes

  • Tidal volume: amount of air entering and leaving the lungs with each breath

  • Vital capacity (VC): greatest amount of air that can be expired after a maximal inspiration

  • Some air always remains in the lungs even after full expiration

  • Residual volume (RV): amount of air remaining in the lungs after a maximal expiration

  • Total lung capacity (TLC): sum of the vital capacity and the residual volume

Page 28:

• Chapter focuses on the Respiratory System and its regulation

• Pulmonary Ventilation is discussed in this chapter

• Activities 7.1, 7.2, 7.3, 7.4, and 7.5 explore different aspects of the respiratory system and its regulation

Page 29:

• Pulmonary Ventilation is the main content of this chapter

• Topics covered include:

  • Anatomy of the Respiratory System

  • Inspiration and Expiration

  • Pulmonary Volumes

  • Pulmonary Diffusion

  • Arterial-Venous Oxygen Difference

  • Gas Exchange at the Muscles

  • Factors Influencing Oxygen Delivery and Uptake

  • Carbon Dioxide Removal

  • Regulation of Pulmonary Ventilation

Page 30:

• Pulmonary Diffusion is the process of gas exchange in the lungs

• It occurs between the alveoli and the capillary blood

• Two major functions of pulmonary diffusion are:

  1. Replenishing the blood's oxygen supply

  2. Removing carbon dioxide from venous blood

Page 31:

• Video recommendation: "Oxygen's surprisingly complex journey through your body"

• Link: https://ed.ted.com/lessons/oxygen-s-surprisingly-complex-journey-through-your-body-enda-butler

• People breathe in around 17,000 times per day

Page 32:

• Pulmonary Diffusion occurs in the lungs

• Blood from the body returns to the right side of the heart through the vena cava

• From the right ventricle, blood is pumped through the pulmonary artery to the lungs and into the pulmonary capillaries

Page 33:

• Chapter focuses on the Respiratory System and its regulation

• Pulmonary Ventilation is discussed in this chapter

• Activities 7.1, 7.2, 7.3, 7.4, and 7.5 explore different aspects of the respiratory system and its regulation

Page 34:

• Pulmonary Diffusion: Blood Flow to the Lungs at Rest

• Lungs receive 4-6L/min of blood flow

• Mean pressure in the pulmonary artery is ~15 mmHg

• Pressure difference across the pulmonary circulation is not great (15 - 5 mmHg)

• Pressure in the left atrium where blood is returning to the heart from the lungs is ~5 mmHg

• Resistance is proportionally lower compared to the systemic circulation

Page 35:

• Chapter focuses on the Respiratory System and its regulation

• Pulmonary Ventilation is discussed in this chapter

• Activities 7.1, 7.2, 7.3, 7.4, and 7.5 explore different aspects of the respiratory system and its regulation

Page 36:

• Pulmonary Diffusion: Respiratory Membrane

• Also called alveolar-capillary membrane

• Gas exchange between the air in the alveoli and the blood in the pulmonary capillaries occurs here

• Anatomy of the membrane includes the alveolar wall, the capillary wall, and their respective basement membranes

Page 37:

• Chapter focuses on the Respiratory System and its regulation

• Pulmonary Ventilation is discussed in this chapter

• Activities 7.1, 7.2, 7.3, 7.4, and 7.5 explore different aspects of the respiratory system and its regulation

Page 38:

• Pulmonary Diffusion: Partial Pressures of Gases

• Amount and rate of gas exchange depend on the partial pressure of each gas

• Gases diffuse along a pressure gradient, moving from an area of higher pressure to one of lower pressure

• Oxygen enters the blood and carbon dioxide leaves it

Page 39:

• Nitrogen, Oxygen, Argon, and Carbon dioxide are the main gases involved in pulmonary diffusion

• Atmospheric pressure at sea level is 760 mmHg

• Oxygen's partial pressure (PO2) is 159.1 mmHg (20.93% of 760 mmHg at sea level)

• Dalton's law states that the total pressure of a mixture of gases equals the sum of the partial pressures of the individual gases in that mixture

• Air composition: 78.09% Nitrogen, 20.95% Oxygen, 0.93% Argon, 0.04% Carbon dioxide

Page 40

• Pulmonary diffusion is the process of gas exchange between the alveoli and the blood.

• The most critical factor for gas exchange is the pressure gradient between the gases in the alveoli and the blood.

• Henry's law states that gases dissolve in liquids in proportion to their partial pressures, depending on their solubilities and temperature.

Page 41

• The chapter discusses the respiratory system and its regulation.

• Pulmonary ventilation, pulmonary volumes, pulmonary diffusion, and arterial-venous oxygen difference are some of the topics covered.

• There is an offline experiment that investigates gas exchange and pulmonary diffusion.

• The regulation of pulmonary ventilation is reviewed in-depth.

Page 42

• Gas exchange in the alveoli is based on the pressure gradient across the respiratory membrane.

• The pressure gradient is created by differences in the partial pressures of gases in the alveoli and the blood.

Page 43

• Oxygen exchange in the alveoli involves a decrease in pressure from inhaled air to alveolar air.

• Alveolar air is saturated with water vapor and contains more carbon dioxide than inspired air.

• Fresh air mixes with the air in the alveoli while some gases are exhaled.

Page 44

• Blood enters the pulmonary capillaries with a lower partial pressure of oxygen (PO2) compared to the alveoli.

• The pressure gradient for oxygen across the respiratory membrane is typically about 60-65 mmHg.

• By the time the blood reaches the venous end of the capillaries, its PO2 equals that in the alveoli.

Page 45

• Fick's law describes diffusion through tissues.

• The rate of diffusion is proportional to the surface area and the difference in partial pressure of gas between the two sides of the tissue.

• The rate of diffusion is inversely