4InhalationThe Intercostal muscles contract, sending the rib cage upward and outwardThe Diaphragm contracts, and moves downwardThe Volume inside of the chest cavity increasesThe Pressure inside the chest cavity decreasesAir enters the lungs to equalize the pressure
5ExhalationThe Intercostal muscles relax, sending the rib cage downward and inwardThe Diaphragm relaxes, and moves upwardThe Volume inside of the chest cavity decreasesThe Pressure inside the chest cavity increasesAir exits the lungs to equalize the pressure
7Carbon Dioxide Concentration Nitrogen Concentration Inhaled vs. Exhaled AirInhaled AirExhaled AirOxygen Concentration21 %16 %Carbon Dioxide Concentration0.04 %5 %Nitrogen Concentration78 %DrynessDrierMoistTemperatureColder or Warmer than 37 CWarm (close to 37 C)CleanlinessDirtier*Cleaner (filtered)*Exhaled air may contain bacteria or viruses, but is cleaner in terms of dust or pollutants
8Turbinate Bones Increase Surface Area and Increase the rate of FilteringWarming andMoistening of air
10Breathing: The act of bringing air in and out of lungs; consists of inhalation and exhalation; it is an external mechanical processCellular (Cell) Respiration: When glucose (food) and oxygen combine to produce carbon dioxide, water and ATP energy; occurs in the mitochondria of cells; it is an internal chemical processEquation: C6H12O6 + O CO2 + H2O + ATP
11How are Breathing and Cell Respiration Connected? In order for cell respiration to occur, oxygen must move into cells, while carbon dioxide must move out of cells.The exchange is made in the lungs during breathing
12Exchanges made between the lungs and the blood are said to be external exchanges, because the lungs are open to the outside of the body.
15Carbon dioxide and oxygen swap places. The gases move by a process called diffusion.In animals, oxygen is moved from the air in the lungs to the blood, and then from the blood to the cells.Carbon dioxidemoves in theoppositedirectionLungsO2BloodCellsCO2
17Label and Color the Alveolus Diagram Use Red for oxygenated bloodand Blue for deoxygenated blood
18Conditions required for Gas Exchange Thin walls (air sacs and blood vessels) – so that gases can pass through the wallsMoist walls – so that gases can dissolve and pass into the blood and cytoplasm of cells (which need materials in liquid, not gaseous form)
193. Concentration gradient – so that gases can move by diffusion; movement of molecules occurs from higher towards lower concentrations4. Pressure gradient – so that the gases can be pushed in the direction that they need to move into; molecules will move from areas of higher towards areas of lower pressureHighLow
20Effect of Altitude on Gas Exchange At Sea Level, Air Pressure is Higher because there are more air particles on top of you
21At high altitudes (like up on a mountain): There are lots of oxygen moleculesBut oxygen molecules can’t get into the body cellsThis is because:There isn’t enough pressureTo push the oxygen from the lungsacross the air sacs,blood vessels,and cell membranesinto the cells where the oxygen is needed.
22At HIGH altitudes…. Pressure Gradient Diffusion Gradient The Diffusion Gradient is in the right direction but the Pressure Gradient is not
23Gas TransportOxygen and Carbon dioxide are carried in the blood stream.Oxygen is carried from the lungs to cells which then use the oxygen for cell respiration.Carbon dioxide is produced by cell respiration and is carried from the cells to the lungs to be exhaled.
24Hemoglobin A chemical found inside red blood cells. It has 4 binding spots for gas molecules.There are many hemoglobin molecules in each red blood cell.Hemoglobin can carryoxygencarbon dioxidehydrogen ionscarbon monoxide
25A hemoglobin molecule consists of 4 Globular proteins (polypeptide chains) bound to a central iron (Fe) atom (called a Heme group)….hence the name Hemo Globin.Blood VesselFeRed blood cell
26Oxygen Transport Oxygen travels through the blood stream in 2 ways: Dissolved in the blood plasma (3%)Attached to hemoglobin – oxyhemoglobin (97%) (Hb O HbO2)Diagram:(3 min. Pre-load to avoid ad, stop showing at graph)Blood vessel97%RBC3% in plasma
27Carbon Dioxide Transport Carbon dioxide travels through the blood stream in 3 ways:Dissolved in the blood plasma (9%)Attached to hemoglobin – carbaminohemoglobin (27%) (Hb CO HbCO2)As a combination of bicarbonate ions dissolved in blood plasma and hydrogen ions attached to hemoglobin - acid hemoglobin (64%)(Hb H HHb)Diagram:Blood Vessel27% CO29% CO2 and 64% HCO3-in plasma64% H+
28If carbonic acid were allow to accumulate in the blood vessels, it would cause respiratory acidosis and could damage blood vessel wallsThe body solves this problem by buffering the bloodOnce hydrogen ions are generated they are “hidden away” inside red blood cells – they attach to hemoglobin to become “acid hemoglobin”The bicarbonate ions are benign and can travel through the blood vessels without causing problems
29Carbon Monoxide Transport Carbon monoxide (CO) binds to hemoglobin 200X more tightly than oxygenEven if there is plenty of oxygen present, the hemoglobin will choose CO over oxygen, leading to the death of the person.Carbon monoxide is a colorless and odorless gas that is a by-product of combustion reactions – found in smoke.It is very important to have a carbon monoxide detector in your home.
30Control of BreathingNumber of breaths per minute taken at rest is about 14-20More when exercisingBreathing rate and heart rate are tied togetherBreather rate and depth control by the medulla oblongata and the pons in the brain
31Nervous Control of Breathing Sensors called chemoreceptors detect CO2 levels in bloodHigher CO2 levels = faster and deeper breathingTo speed rate and depth of breathing, the brain sends messages to the diaphragm & intercostal muscles using sympathetic nerves
32Nervous Control of Breathing BrainNervous Control of BreathingMuscles contract faster to speed up rate of breathing when CO2 is highMuscles contract slower to slow rate of breathing when CO2 is low
36High Altitude Athletic Training Training in places with higher elevations (ex. Colorado) in order to increase lung capacity and thus performanceAt first - breathing & heart rates will be higher than normalAfter a few months of training....The lungs have stretchedBreathing rates return to normal breaths/minuteMore capillaries grew around alveolito accommodate a faster gas exchangeMore red blood cells will have been addedto the blood stream for a greateroxygen carrying capacity.The athlete then returns to loweraltitudes to compete