The Respiratory System (Hapara) PDF

The Respiratory System Lesson 3  Learning Goals Today I will… ❏ use appropriate terminology related to animal anatomy; ❏ explain the anatomy of the respiratory system and the process of ventilation and gas exchange from the environment to the cell.. Functions of the Respiratory System Suppli...

The Respiratory System Lesson 3  Learning Goals Today I will… ❏ use appropriate terminology related to animal anatomy; ❏ explain the anatomy of the respiratory system and the process of ventilation and gas exchange from the environment to the cell.. Functions of the Respiratory System Supplies oxygen to cells Removes carbon dioxide Defense against microorganisms Produces sound for communication Controls body fluid pH Respiration Gas Exchange & Ventilation Gas Exchange Ventilation Happens at the cellular level. Deals with the respiratory Diffusion causes cells to system structures. exchange oxygen and carbon Process of moving dioxide. oxygen-rich air to the lungs, Happens at the lungs and the and carbon dioxide-rich air body cells. away (aka. breathing). Respiratory Structures in Mammals 4 necessary structures: A thin, permeable membrane to allow diffusion Large surface area for gas exchange Good blood supply A breathing system for ventilation From Mouth to Lungs: Trachea & Bronchi Air travels from the mouth and nose (nostrils), through the pharynx and to the trachea. Trachea: a semi-rigid tube lined with mucous-producing cells and cilia. The trachea branches into two bronchi. From Bronchi to Lungs Each bronchus connects to a lung. Inside the lung, the bronchi branch into smaller bronchioles. Bronchioles end in small sacs called alveoli. Gas Exchange in Alveoli Alveoli are surrounded by a capillary network. Air has been warmed to body temperature and is moist. O2 and CO2 can diffuse across the thin membrane. Partial Pressures The air we breathe is made of a mixture of different gases. Partial pressure: the pressure of each individual gas in a mixture that makes up the total pressure of a mixture. Partial Pressure & Gas Exchange Partial pressure of gases affect gas exchange. Gases will diffuse across a membrane from areas of high pressure to low pressure until the pressure is equal The greater the pressure gradient, the higher the rate of diffusion. Gas Exchange at the Alveoli O2 moves from the air in the alveoli (high pressure) into the blood plasma where the pressure is lower. The circulatory system transports O2 attached to hemoglobin (98.5%) and dissolved in the plasma (1.5%). Carbon Dioxide Transport CO2 produced by cellular respiration dissolves in tissue fluid around cells forming carbonic acid (H2CO3). H2CO3 separates into H+ and HCO3- and then recombines in the blood stream to form H2O and CO2. CO2 diffuses across the membrane of the alveoli into the lungs to be exhaled. Trace the Path of an Oxygen Molecule Use the following structures starting at the nose and ending at a cell in muscle tissue. alveoli, aorta, capillary, pharynx, mitral valve, left ventricle, capillary, arteriole, trachea, bronchiole, aortic valve, left atrium, bronchi, pulmonary vein, artery Altitude and Respiration The respiratory system faces challenges at high altitude. Above 7,000 m, the atmospheric pressure is so low, humans can't survive. A breath of air at high altitude contains fewer oxygen molecules than a breath at sea level. Ventilation Ventilation (breathing) is an involuntary action controlled by the brain stem. Cells in the medulla oblongata in the brain and receptors in the carotid artery monitor blood pH; a low pH indicates too much CO2. The Diaphragm Dome-shaped muscle separating the chest and abdominal cavity; the primary muscle in breathing. Inspiration (Inhalation) Diaphragm contracts = more space in thoracic cavity = lower pressure. Intercostal muscles pull ribcage up and out = lower pressure Pressure is greater outside of lungs so air moves in. Exhalation Diaphragm relaxes = moves up into thoracic cavity = pressure increase External intercostal muscles pull ribcage down during exercise (not during normal breathing). Lung Capacity Total lung volume depends on sex, body type, and lifestyle. Males, non-smokers, and athletes have the largest volume Lung Capacity The tidal volume in normal breathing is approximately 10% of total lung capacity. Oxygen Usage VO2 = rate at which oxygen is used in the body. VO2 max = maximum amount of oxygen used during sustained, intense exercise A high maximum rate of oxygen usage = efficient respiratory system