A-Level Biology - Circulatory Systems - Why We Need Them | Key Components | Types (2026/27 exams)

⭐️ Check out our website https://www.cognito.org/ ⭐️ *** WHAT'S COVERED *** 1. Why multicellular organisms need transport systems. * The limitations of simple diffusion in large organisms. * The role of high metabolic rates. * The three key components of all transport systems: a medium, a network, and a pump. 2. The different types of circulatory systems found in animals. * A comparison between open circulatory systems (e.g., invertebrates) and closed circulatory systems (e.g., vertebrates). * A comparison between single circulation (e.g., fish) and double circulation (e.g., mammals). 3. The mammalian double circulatory system. * An overview of the double, closed system in mammals like humans. * The two main pathways: pulmonary circulation (to the lungs) and systemic circulation (to the rest of the body). * The functions of major blood vessels, including the pulmonary artery, pulmonary vein, aorta, vena cava, renal artery, and renal vein. *** EXAM BOARD SPECIFIC INFO *** AQA / CIE - You don't need to know about the differences between single and double or open and closed circulatory systems, you just need to know that the mammalian circulatory system is a closed, double circulatory system and what that means OCR - Everything is relevant to your course! *** CHAPTERS *** 0:00 Introduction to Circulatory Systems 0:24 Why Organisms Need Transport Systems 1:01 The Three Components of a Transport System 1:32 Open vs Closed Circulatory Systems 3:21 Single vs Double Circulatory Systems 4:37 The Mammalian Double Circulatory System 4:53 Pulmonary Circulation and Systemic Circulation 5:07 Major Blood Vessels in the Mammalian System *** PLAYLISTS *** https://youtube.com/playlist?list=PLidqqIGKox7VzYfPIVt8T09xOLNcolCe4&si=8JmDajxjtba6rdc3 https://youtube.com/playlist?list=PLidqqIGKox7UZ3mWhbHv2aA_1vnbsfRPq&si=q3hEKdA4v7kbfwMe https://www.youtube.com/playlist?list=PLidqqIGKox7UTimdJ3eFcnt6xL9GUt2a6 https://youtube.com/playlist?list=PLidqqIGKox7XPh1QacLRiKto_UlnRIEVh&si=orIUwL3o2jOoiYjT https://youtube.com/playlist?list=PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g&si=DcihOwUkd9oWbbdp https://youtube.com/playlist?list=PLidqqIGKox7WeOKVGHxcd69kKqtwrKl8W&si=Y8MsO-FK948jnxpS https://youtube.com/playlist?list=PLidqqIGKox7UVC-8WC9djoeBzwxPeXph7&si=-7i5Iq7yOeJrhtu6 https://youtube.com/playlist?list=PLidqqIGKox7VKJD2WxRhoKaI6JGLVean8&si=NH_Q1ujhVgACM2FU #alevel #Biology #study #revision #school #exam #AQA #OCR #Edexcel