BIOL 1108 Edition 1nd Lecture 14 Outline of Last Lecture I Learning Objectives II In The News III Electrical Signals IV Resting Potential to Action Potential V Action Potential Propagation Outline of Current Lecture I Learning Objectives II Circulation III Gas Exchange Current Lecture I II Learning Objectives 1 Be able to Describe structures and functions animals use to exchange substances with their environment including o 2 circulatory systems o 3 main respiratory systems 2 Compare and contrast circulatory systems and respiratory systems relative to animals environment and habits Circulation Circulatory systems link exchange surfaces with cells throughout the body o Naturally Selected Solutions Body size and shape To keep cells in contact with their environment Circulatory system These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Moves fluid between each cell s surroundings and the environment o Functions Exchange gases Absorb nutrients Dispose waste For animals with many cell layers the circulatory system contains o Circulatory fluid Blood or hemolymph o Interconnecting vessels Arteries capillaries ect o Muscular Pump Heart Circulatory Systems o Open circulatory system Hemolymph in sinuses surrounding organs Fluid is opened up into the body cavity Body movement assists fluid distribution throughout the body Ex Grasshopper jumping o Closed circulatory system Small branch vessels in each organ Larger and smaller vessels are farther apart and closer to more cells Creates a loop Ex Earthworm For humans and other vertebrates blood moves through the heart and vessels Blood Vessels o Arteries Carry blood from heart to organs oxygenated Arterioles smaller vessels within organs that transport blood to the capillaries o Capillaries Microscopic with porous walls Capillary beds networks pass within a few cell diameters of every cell in the body o Veins Carry blood back to heart deoxygenated Hearts o 2 or more chambers Atria receives blood into the heart Ventricles pump blood out of the heart III Closed Circulatory Systems Types o Single Circulation Goes through the heart once in a complete loop Ex Fish o Double Circulation Goes through the heart twice in a loop Advantage allows more efficiency throughout the body more oxygen Amphibians o Pulmocutaneous and systemic circuit o 3 chambered heart o Mixing of oxygen rich and oxygen poor blood o Allows them to absorb oxygen through their skin or air o Life cycle involved both aquatic and terrestrial Reptiles o Pulmonary and systematic circuit o 3 chambered heart with an incomplete septum o Has an extra loop for more blood flow when they get cold o Adaptation ectothermic o More vessels get oxygenated when not breathing o Basking in the sun submerged under water Mammals and Birds o Pulmonary and systemic circuit o 4 chambered heart o Specialized internal lungs o Septum separates the two portions of the heart allows more efficient blood flow with oxygen o Heart is more efficient and beneficial to do high energy activities Gas Exchange Uptake of molecular O2 from the environment and discharge CO2 into the environment Respiratory Media o Partial pressure pressure exerted by a particular gas in a mixture a gasses Gas diffuses from higher to lower partial pressure o Water and Air O2 is much less soluble in water than air 40 times harder to get O2 in water than in air Respiratory Surfaces o Plasma membrane in contact with an aqueous solution i e always moist Frogs earthworms have moist skin in wet environment o Increasing surface area increases diffusion Ex Lungs contain cilia o Decreasing exchange distance increases diffusion Ex Body shape To maximize surface area and decrease exchange distance capillaries decrease the number of cells getting oxygen in certain areas o Gas exchange structures are large and thin o Skin can be used as a respiratory organ but it must remain moist 3 Main Respiratory Organs o Gills external allows water to run through Countercurrent Exchange Obtained by either swimming through water or forcing water through gills in a running stream o Trachea tubes go through the body system opening allows air into the body cavity to cells Direct path from air to cells for diffusion Most common Used by insects o Lungs Get oxygen from air into the blood stream to heart and rest of the body via alveoli and capillaries Nasal cavity filters foreign objects out of the body through cilia High surface area to volume area in lungs