Respiration & Gas Exhange Slide 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 bodys cells. We will focus on the exchange of gases. Slide 3 So what are the functions of the respiratory system? Bring oxygen into the body Remove carbon dioxide (CO 2 ) from the body Clean, moisten and warm air Enable speech Slide 4 Gas exchange supplies oxygen for cellular respiration and removes CO 2 Gas exchange uptake of O2 from environment and discharge of CO2 Mitochondria need O2 to produce more ATP, CO2 is the by-product C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36 ATP DIFFUSION Slide 5 How Does Oxygen Get Into Cells? O 2 and CO 2 enter and leave the cells (gas exchange) by diffusion Different animals have different systems Some examples: Organism:Gas exchange between: one-celledcell membrane and outside cell earthwormskin and capillaries insectstrachea and body cells fishgill filaments and capillaries mammalsair sacs (alveoli) and capillaries Slide 6 Respiratory surfaces and gas exchange Respiratory surface Size of organism Habitat Metabolic demands Unicellular organisms Entire surface area for diffusion Simple invertebrates Sponges, cnidarians, flatworms diffusion Slide 7 Human Respiratory System Our own pathway, in order: Mouth/Nasal Cavity Pharynx Larynx Trachea Bronchi Bronchioles Alveoli (tiny air sacs) Slide 8 Mammalian respiration Slide 9 Organs of the respiratory system Nose and sinuses Q. List the advantages of breathing in from the nose? (page 170 ) 1. Cleans dust and bacteria in the air by hair and mucus, 2. warms and moistens the air 3. Detect harmful chemicals by sensory cells Slide 10 Organs of the respiratory system Pharynx short tube leading to larynx Epiglottis cartilaginous flap covering opening to larynx (glottis) Larynx voicebox containing vocal cords Hyoid Bone Epiglottis Thyrohyoid Membrane Cricothyroid Ligament Cricothyroid Muscles Cricothyroid Cartilage Trachea Thyroid Cartilage Slide 11 Organs of the respiratory system Trachea tubes leading into lungs. These branch into primary bronchi then into bronchioles mouth trachea bronchi alveoli Slide 12 larynx bronchiole sinuses pharynx trachea alveoli bronchial tube Slide 13 Organs of the respiratory system Bronchioles end in sac like structures called Alveoli Gas exchange occurs between the alveoli and capillaries Primary bronchus Alveoli Terminal bronchiole Bronchiole Tertiary bronchus Secondary bronchus Slide 14 Bronchial Tubes Slide 15 Gas Exchange Capillaries surround the alveoli Gases are exchanged between the thin walls of the alveoli and capillaries Slide 16 How Does O 2 Get Into the Blood? Alveolus (air sac) Pulmonary capillary O2O2 CO 2 From heart To heart A i r A i r Slide 17 How Does O 2 Get Into the Blood? Blood needs a special chemical to carry the oxygen: Hemoglobin oxygen sticks to or binds with hemoglobin in red blood cells hemoglobin contains iron which binds with oxygen Can you follow the oxygen? In the lungs: Oxygen diffuses from the air in the alveoli into capillaries Oxygen passes into red blood cells and binds with hemoglobin In the blood, oxygen remains bound to hemoglobin until it reaches your cells At your cells: CO 2 diffuses from cells into capillaries Hemoglobin releases oxygen and binds with CO 2 Oxygen diffuses from red blood cells into your body cells Slide 18 How Air Moves in and Out Inhaling: getting air with oxygen in Exhaling: getting air with carbon dioxide out Air 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: Boyles Law Slide 19 Robert Boyle discovered that if: volume decreases, pressure increases volume increases, pressure decreases Pressure and volume are inversely related: If one increases, the other decreases This is called an inverse relationship Gases always move from: areas of higher pressure to areas of lower pressure Boyles Law explains how air is forced into and out of your lungs ! Slide 20 1.Diaphragm & rib muscles (external intercostal muscles) contract 2.Rib cage expands 3.Volume in lungs increases 4.Pressure in lungs decreases 5.Air pressure outside is greater 6.Air rushes into lungs 1. 2. 3. 4. 5. 6. Can you fill in steps 1- 6 for exhaling? Slide 21 Lung ventilation through breathing Negative pressure breathing in reptiles and mammals Rib muscles and diaphragm change lung volume and pressure Slide 22 Lung volumes Factors Smoking, increase due to CO Anxiety, increase due to the effect of adrenaline Drugs, some may cause an increase Environmental factors, increased by high CO2 concentration in the atmosphere Altitude, increased by low O2 conc. In the atmosphere Weight, can increase because fat makes lung ventilation harder (i.e tidal volume falls), Tidal volume Volume of air inhaled and exhaled with each breath Vital capacity Maximum volume inhaled and exhaled during forced breathing Residual volume Air left in alveoli after forced exhalation Slide 23 Control centers in the brain regulate breathing Slide 24 Gases diffuse down pressure gradients concentration and pressure drives the movement of gases into and out of blood Slide 25 Respiratory System Problems Dirt, pollen, dust, and smoke damage the system and interrupt the flow of oxygen to your cells Respiratory System Defenses: WWhite blood cells Surround, consume, and digest bacteria Cannot consume asbestos CCilia Tiny hairs lining trachea Hairs wave upward to expel foreign particles Cigarette smoke paralyzes cilia Defense against choking: TThe epiglottis FFlap of tissue that closes trachea when you swallow MMakes certain food travels through esophagus instead Slide 26 Respiratory Disorders Asthma BBronchial tubes become constricted SSymptoms: shortness of breath, wheezing, coughing CCauses: environmental factors: allergies, stress, certain foods Emphysema AAlveoli lose ability to expand and contract when breathing AAlveoli stretch and rupture; scar tissue develops LLess oxygen to cells + buildup of CO 2 Lung cancer CCaused by tars and other carcinogens in cigarette smoke CCancerous tumors destroy lung tissue Effects of smoking: SShort term: carbon monoxide (CO) replaces oxygen in blood LLong term: heart disease, emphysema, lung cancer WWithout smoking, these disorders are a minor problem in society Slide 27 Review Questions 1.Which term does not belong with the others and why not? gills, alveoli, diaphragm, trachea asthma, respiration, emphysema, lung cancer gills, lungs, hemoglobin lung cancer, asthma, emphysema alveoli, diaphragm, trachea 2.Explain what happens to your diaphragm and ribcage when you inhale and exhale. 3.What are the reactants and products of cell respiration? 4.Use Boyles Law to explain inhaling, exhaling, and why the Heimlich Maneuver works. 5.Describe how gas exchange occurs in the lungs. 6.Why is your trachea lined with cartilage? 7.What is the function of your nasal cavity? 8.What is your epiglottis and what is it for? 9.Why do you have cilia inside your trachea? 10.Which respiratory condition can be the result of allergies?