Respiratory System
1.Exchange Why do of we gases breathe? into the Think blood of all and the tissues. reasons Diffusion why we of Oxygen need a respiratory into blood from the lungs system. and then into the tissues. Diffusion of wastes such as Carbon Dioxide from tissues into blood and out of blood into the lungs. 2.Cellular Respiration requires oxygen in order to produce useable energy in order to carry out cellular processes and to prevent the build up of lactic acid via anaerobic respiration. T H I N K I T O U T
Respiration Respiration is used several different ways: Cellular respiration is the aerobic breakdown of glucose in the mitochondria to make ATP. Respiratory systems are the organs in animals that exchange gases with the environment. Respiration is an everyday term that is often used to mean breathing.
Respiration External Respiration The exchange of gases between the atmosphere and blood Internal Respiration The exchange of gases between the blood and cells in our bodies
Respiratory system function Respiratory systems allow animals to move oxygen (needed for cellular respiration) into body tissues and remove carbon dioxide (waste product of cellular respiration) from cells.
Gas exchange by Diffusion Some animals simply allow gases to diffuse through their skins These animals have a low metabolic rate All of these are aquatic animals
Specialized structures Structures specialized for gas exchange include: gills (aquatic animals) spiracles (terrestrial insects) lungs (most terrestrial vertebrates)
Fish Gills Fish increase gas exchange efficiency using countercurrent exchange. Running blood through the system in the opposite direction to water keeps a diffusion gradient throughout the entire exchange.
Countercurrent Exchange In a concurrent system, exchange is inefficient. Equilibrium is reached at one end. In a countercurrent system, equilibrium is not reached, so gas exchange continues, increasing efficiency.
Gills exchange gases in fish. What is the site of gas exchange in mammals? 1. Alveoli 2. Tracheids 3. Bronchi 4. Esophagus
1.Gills are an adaptation developed to Why are gills so widely seen in aquatic support gas exchange underwater animals but not in land animals? because gases must diffuse from the water in order to fuel the tissues of the aquatic organisms. Conversely, terrestrial organisms do not require gills but respiratory organs that can diffuse the readily available gases directly into the organisms blood and tissues. T H I N K I T O U T
Human respiratory system Parts of the respiratory system include: Pharynx Trachea Larynx Epiglottis
Human respiratory system Parts of the respiratory system include: Bronchi Bronchioles Alveoli Lungs
Pharynx Known as the throat A tube at the back of the nasal cavity and mouth Acts as a main passageway for both food and air
Epiglottis A cartilaginous flap that covers the air passage when food is swallowed It presses down, sealing the pathway When air is taken in, the epiglottis stands upright
Trachea Known as the windpipe This is a cartilaginous tube that allows air to pass Roughly 10-12cm long and has ciliated cells
Larynx Known as the voicebox Has two ligaments that are stretched across it. (these are our vocal cords) The amount of air as well as the tension on the cords determine the sounds produced
We have two. Singular = Bronchus They both lead to the lungs and are made of both smooth muscle and cartilage. Also lined with ciliated cells and mucus Bronchi
Bronchioles The smallest divisions of the Bronchi Structurally similar to bronchi Also lined with ciliated cells and mucus
Alveoli Described as clusters of tiny air sacs Singular = alveolus Each houses a network of capillaries Function = gas exchange
Lungs We have two: The right lung has three lobes and the left has only two Pleura- membranes that secrete a sticky fluid that decrease friction Lines the entire thoracic cavity and lungs Function = gas exchange between atmosphere and blood
The Path of Air
Moving air in and out During inspiration (inhalation), the diaphragm and intercostal muscles contract. During expiration (exhalation), these muscles relax. The diaphragm domes upwards.
Alveoli The alveoli are moist, thin-walled pockets which are the site of gas exchange. A slightly oily surfactant prevents the alveolar walls from collapsing and sticking together.
Circulation and Gas Exchange Recall the interconnection between circulation and the respiratory system. Gas exchange at the lungs and in the body cells moves oxygen into cells and carbon dioxide out.
What happens when you breathe 1. The rib muscles relax. 2. The diaphragm contracts. 3. Air leaves the alveoli. 4. Air moves between the chest wall and the lung. in?
Absence of or too little surfactant produced in the lungs at the site of the alveoli causing the alveoli to collapse on top of themselves and thus containing Premature no air and maintaining infants sometimes no lung capacity. die of lung collapse and other lung problems. What Also, might infections preemies while be baby missing? in womb How can could lead to this be remedied? lung collapse. T H I N K I T O U T
In the alveolus
In the alveolus The respiratory surface is made up of the alveoli and capillary walls. The walls of the capillaries and the alveoli may share the same membrane.
Gas exchange Air entering the lungs contains more oxygen and less carbon dioxide than the blood that flows in the pulmonary capillaries. How do these differences in concentrations assist gas exchange?
Oxygen transport Hemoglobin binds to oxygen that diffuses into the blood stream. What are some advantages to using hemoglobin to transport oxygen?
Oxygen transport There are approximately 250 million hemoglobin molecules per RBC Hemoglobin is a protein made up of 4 polypeptide chains, each bonded is bonded to a haem (iron) group. Hemoglobin is able to increase the oxygen-carrying capacity of blood by carrying 4 oxygen molecules. Thus, much more oxygen can be transported around the blood in hemoglobin, rather than being dissolved in plasma. Another advantage is that once 1 oxygen molecule binds to the hemoglobin its ability to bind more oxygen molecules increases. The bonding of each oxygen molecule slightly alters the shape of the hemoglobin, making it easier for subsequent molecules to bind to it.
Oxygen transport Another advantage is that hemoglobin's capacity to release oxygen increases in the presence of carbon dioxide. Once hemoglobin releases oxygen it has an increased ability to pick up carbon dioxide. The fact that hemoglobin is enclosed inside red blood cells, means that it doesn t disturb the osmotic balance of the blood plasma.
Bohr Effect Bohr Effect- stating that hemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide. What does it mean?
Bohr Effect Since carbon dioxide reacts with water to form carbonic acid, an increase in CO 2 results in a decrease in blood ph, resulting in hemoglobin proteins releasing their load of oxygen. Conversely, a decrease in carbon dioxide provokes an increase in ph, which results in hemoglobin picking up more oxygen. The dissociation of carbonic acid increases the acidity of the blood (decreases its ph). Hydrogen ions, H +, then react with oxyhemoglobin to release bound oxygen and reduce the acidity of the blood. This buffering action allows large quantities of carbonic acid to be carried in the blood without major changes in blood ph.
Carbon dioxide transport Carbon dioxide can dissolve in plasma, and about 70% forms bicarbonate ions. Some carbon dioxide can bind to hemoglobin for transport.
Carbon dioxide transport H 2 O + CO 2 H 2 CO 3 HCO 3- + H + HCO 3- + H + H 2 CO 3 H 2 O + CO 2
Carbon dioxide transport 1. CO2 diffuses into RBCs 2. Carbonic Anhydrase catalyzes CO2 into carbonic acid in the presence of water 3. Carbonic acid is unstable and disassociates into bicarbonate and protons 4. Bicarbonate is able to leave the RBC by way of the RBC accepting Chloride in exchange. This is called Chloride Shift. 5. This allows more CO2 to be taken in by RBC and also for the bicarbonate to travel
Carbon dioxide transport 6. Normally, too many H+ ions released into the blood would alter the ph, but hemoglobin will bind free H+ 7. When blood reaches the lungs, bicarbonate is transported back into RBC and chloride is released 8. H+ ions disassociate from hemoglobin and binds to bicarbonate 9. This produces carbonic acid which is then catalyzed back into CO2 and expelled via expiration
Cells use up oxygen quickly for cellular respiration. What does this do to the diffusion Here we gradient? are simply How speaking does about this the help cells take up oxygen? concentration gradients fueled by the unbalanced proportion of both O2 and CO2. This unbalance drives diffusion (the movement of Cells create carbon dioxide during molecules cellular from respiration, an area of so high CO2 concentration levels in the to an cell area are of higher lower concentration) than in the blood and allows coming the to them. cells to How uptake O2 does this and to help expel CO2 cells get rid of CO2? T H I N K I T O U T
Respiration Rate Increased activity = Increased Breathing SIMPLE
The oxygen in blood is: 1. Bound to hemoglobin. 2. In the white blood cells. 3. Combined with carbon to make carbon dioxide. 4. Dissolved in the plasma.
Diffusion of O 2 from lungs to blood is rapid because: 1. Active transport moves oxygen. 2. Hemoglobin takes up oxygen, keeping plasma concentration low. 3. Blood plasma is oxygen-rich.
Effects of smoking Inhaled smoke contains: CO2, which affects the CO2 diffusion gradient. Carcinogenic chemicals that can trigger tumors. Toxic nicotine, which paralyzes cilia that normally clean the lungs.
Emphysema Besides cancer, smoking can also lead to emphysema. Alveoli become dry and brittle, and eventually rupture. Both active and passive smoking ( secondhand smoke) can lead to can lead to lung problems. All types of smoke, not just tobacco, can cause cancers and emphysema.
Emphysema
Cystic Fibrosis Cystic fibrosis is one of the most common inherited respiratory disorders in The U.S. CF is caused by mutation of a single gene, the CFTR gene, which controls salt balance in the lungs.
Cystic Fibrosis A normal CFTR protein regulates the amount of chloride ions across the cell membrane of lung cells. If the interior of the cell is too salty, water is drawn from lung mucus by osmosis, causing the mucus to become thick and sticky.
Cystic Fibrosis At this point there is no cure for CF, though there are therapies that have extended the lives of CF patients, including lung transplants. Gene therapy may one day insert good CFTR genes into lung cells to make them operate normally.
Two lies and a truth which one 1. Cigarette smoke cures colds because it kills bacteria in the lungs. 2. Passive smoking is less harmful than regular smoking. 3. Nicotine is one of the most potent neurotoxins on earth. is true?
When people quit smoking, if the lungs Mucus is a sticky substance used are not damaged they can often clean to trap dust and microbes. themselves because the cilia are no Cilia are tiny hairs which line the longer paralyzed. People with cystic cells and tracts of the respiratory fibrosis system have in order trouble to sweep with lung these infections because contaminates their lung away mucus from the is thick lungs and sticky. What and toward roles do the cilia throat. and mucus play in lung health? TH I N K I T O U T