2 Respiration Two processes: 1. Release of energy from breakdown of food molecules.All living cells use oxygen to release energy.This process produces waste carbon dioxide.2.The exchange of gases between the atmosphere and body’s cells.We will focus on the exchange of gases.
3 So what are the functions of the respiratory system? Bring oxygen into the bodyRemove carbon dioxide (CO2) from the bodyClean, moisten and warm airEnable speech
4 Gas exchange supplies oxygen for cellular respiration and removes CO2 …………………………………………………………………………………………………………………Gas exchange supplies oxygen for cellular respiration and removes CO2Gas exchange – uptake of O2 from environment and discharge of CO2Mitochondria need O2 to produce more ATP, CO2 is the by-productC6H12O6 + 6O2 6CO2 + 6H2O + 36 ATPDIFFUSION
5 How Does Oxygen Get Into Cells? O2 and CO2 enter and leave the cells(gas exchange) by diffusionDifferent animals have different systemsSome examples:Organism: Gas exchange between:one-celled cell membrane and outside cellearthworm skin and capillariesinsects trachea and body cellsfish gill filaments and capillariesmammals air sacs (alveoli) and capillaries
6 Respiratory surfaces and gas exchange Size of organismHabitatMetabolic demandsUnicellular organismsEntire surface area for diffusionSimple invertebratesSponges, cnidarians, flatwormsdiffusion
7 Human Respiratory System Our own pathway, in order:Mouth/Nasal CavityPharynxLarynxTracheaBronchiBronchiolesAlveoli (tiny air sacs)
9 Organs of the respiratory system Nose and sinusesQ. List the advantages of breathing in from the nose? (page 170 )1. Cleans dust and bacteria in the air by hairand mucus,2. warms and moistens the air3. Detect harmful chemicals by sensory cells
10 Organs of the respiratory system Hyoid BoneEpiglottisThyrohyoidMembraneCricothyroidLigamentMusclesCartilageTracheaThyroidPharynx – short tube leading to larynxEpiglottis – cartilaginous flap covering opening to larynx (glottis)Larynx – voicebox containing vocal cords
11 Organs of the respiratory system Trachea – tubes leading into lungs.These branch into primary bronchi then into bronchiolesmouthtracheabronchialveoli
13 Organs of the respiratory system Bronchioles end in sac like structures called AlveoliGas exchange occurs between the alveoli and capillariesPrimarybronchusAlveoliTerminalbronchioleBronchioleTertiarySecondary
15 Gas Exchange Capillaries surround the alveoli Gases are exchanged between the thin walls of the alveoli and capillaries
16 How Does O2 Get Into the Blood? AirToheartFromheartAirAlveolus(air sac)O2CO2Pulmonary capillary
17 How Does O2 Get Into the Blood? Blood needs a special chemical to “carry” the oxygen:Hemoglobinoxygen “sticks to” or binds with hemoglobin in red blood cellshemoglobin contains iron which binds with oxygenCan you follow the oxygen?In the lungs:Oxygen diffuses from the air in the alveoli into capillariesOxygen passes into red blood cells and binds with hemoglobinIn the blood, oxygen remains bound to hemoglobin until it reaches your cellsAt your cells:CO2 diffuses from cells into capillariesHemoglobin releases oxygen and binds with CO2Oxygen diffuses from red blood cells into your body cells
18 How Air Moves in and Out Inhaling: getting air with oxygen in Exhaling: getting air with carbon dioxide outAir is forced into and out of your lungs.But how?When you squeeze a plastic bottle, what does the air do? Which direction does it move?When you let the plastic bottle spring back into shape, what does the air do? Which direction does it move now?This is because of an important law of how gases work:Boyle’s Law
19 Boyle’s Law Robert Boyle discovered that if: volume decreases, pressure increasesvolume increases, pressure decreasesPressure and volume are inversely related:If one increases, the other decreasesThis is called an inverse relationshipGases always move from:areas of higher pressure to areas of lower pressureBoyle’s Law explains how air is forced into and out of your lungs !
20 1. Diaphragm & rib muscles (external intercostal muscles) contract 2. Rib cage expands3. Volume in lungs increases4. Pressure in lungs decreases5. Air pressure outside is greater6. Air rushes into lungs22.214.171.124.5.6.Can you fill in steps 1- 6 for exhaling?
21 Lung ventilation through breathing Negative pressure breathing in reptiles and mammalsRib muscles and diaphragm change lung volume and pressure
22 Lung volumes Factors Vital capacity Residual volume Tidal volume Smoking, increase due to COAnxiety, increase due to the effect of adrenalineDrugs, some may cause an increaseEnvironmental factors, increased by high CO2 concentration in the atmosphereAltitude, increased by low O2 conc. In the atmosphereWeight, can increase because fat makes lung ventilation harder (i.e tidal volume falls),Tidal volumeVolume of air inhaled and exhaled with each breathVital capacityMaximum volume inhaled and exhaled during forced breathingResidual volumeAir left in alveoli after forced exhalation
23 Control centers in the brain regulate breathing
24 Gases diffuse down pressure gradients concentration and pressure drives the movement of gases into and out of blood
25 Respiratory System Problems Dirt, pollen, dust, and smoke damage the system and interrupt the flow of oxygen to your cellsRespiratory System Defenses:White blood cellsSurround, consume, and digest bacteriaCannot consume asbestosCiliaTiny hairs lining tracheaHairs “wave” upward to expel foreign particlesCigarette smoke paralyzes ciliaDefense against choking:The epiglottisFlap of tissue that closes trachea when you swallowMakes certain food travels through esophagus instead
26 Respiratory Disorders AsthmaBronchial tubes become constrictedSymptoms: shortness of breath, wheezing, coughingCauses: environmental factors: allergies, stress, certain foodsEmphysemaAlveoli lose ability to expand and contract when breathingAlveoli stretch and rupture; scar tissue developsLess oxygen to cells + buildup of CO2Lung cancerCaused by “tars” and other carcinogens in cigarette smokeCancerous tumors destroy lung tissueEffects of smoking:Short term: carbon monoxide (CO) replaces oxygen in bloodLong term: heart disease, emphysema, lung cancerWithout smoking, these disorders are a minor problem in society
27 Review QuestionsWhich term does not belong with the others and why not?gills, alveoli, diaphragm, tracheaasthma, respiration, emphysema, lung cancergills, lungs, hemoglobinlung cancer, asthma, emphysemaalveoli, diaphragm, tracheaExplain what happens to your diaphragm and ribcage when you inhale and exhale.What are the reactants and products of cell respiration?Use Boyle’s Law to explain inhaling, exhaling, and why the Heimlich Maneuver works.Describe how gas exchange occurs in the lungs.Why is your trachea lined with cartilage?What is the function of your nasal cavity?What is your epiglottis and what is it for?Why do you have cilia inside your trachea?Which respiratory condition can be the result of allergies?