Animal Transport Notes - IGCSE Biology - PRE PDF

# **PRE BIO – Ch: Animal Transport** ## Blood Vessels ### Blood Vessels Table | Blood Vessel | Function | |---|---| | Artery | Takes blood *away* from the heart | | Vein | Takes blood *toward* the heart | | Capillaries | Connect arteries to veins | ### Artery * **Structure:** Thick walled, Nar...

# **PRE BIO – Ch: Animal Transport** ## Blood Vessels ### Blood Vessels Table | Blood Vessel | Function | |---|---| | Artery | Takes blood *away* from the heart | | Vein | Takes blood *toward* the heart | | Capillaries | Connect arteries to veins | ### Artery * **Structure:** Thick walled, Narrow lumen, No valves * **Function:** Carry blood *away* from the heart * **Blood Pressure:** High pressure ### Vein * **Structure:** Thin walled, Large lumen, Valves present * **Function:** Carry blood *toward* the heart * **Blood Pressure:** Low pressure ### Capillary * **Structure:** Single cell thickness of wall, Extremely narrow lumen, No valves * **Function:** Allow exchange of materials between arteries and veins * **Blood Pressure:** Reducing pressure ## Diagram: Sections through the three types of blood vessels * Section: **Artery** * Thick outer wall * Small lumen * Thick layer of muscles and elastic fibres * Section: **Vein** * Thin layer of muscle and elastic fibers * Large lumen * Fairly thin outer wall * Section: **Capillary** * Very small lumen * Wall made of a single layer of cell ## Diagram: Sections through the three types of blood vessels * The diagram displays an arrow going from the heart to an artery. * Another arrow shows how the artery branches into capillaries. * The capillaries then converge into a vein that carries blood back to the heart. ## Components of Blood | Component | Characteristics | |---|---| | RBCs | * Made in the bone marrow * Transport O₂ from lungs to all respiring tissues * Have no nucleus * Have a special biconcave disc shape | | WBCs | * Made in the bone marrow and in the lymph nodes * Have a nucleus, often large and lobed * Can move around and squeeze out through the walls of blood capillaries into all parts of the body. * There are many different kinds of white blood cells. They all have the function of fighting disease-causing bacteria and viruses and to clear up any dead body cells in your body: | | Platelets | * Small fragments of cells, with no nucleus. * Made in the bone marrow. * Involve in blood clotting: form blood clot, which stop blood loss at a wound and prevent the entry of germs into the body. | | Plasma | The liquid part of the blood containing water and other substances like minerals, nutrients and hormones | ## Circulation Types ### Single Circulation * **How:** Blood only passes through the heart *once* * **Occurs in:** Fish ### Double Circulation * **How:** Blood passes through the heart *twice* * **Occurs in:** Mammals ## Diagram: Single Circulation * **Diagram shows the blood flowing from the heart to the gills and then to the body and back to the heart** ## Diagram: Double Circulation * **Diagram shows the blood flowing from the heart to the lungs and then back to the heart, and from the heart to the body and then back to the heart** ## Anatomy of the Heart ### Chambers * **4 Chambers:** 2 Atria (left and right), 2 Ventricles (left and right) * **4 Valves:** 2 Atrioventricular valves, 2 Semilunar valves * **4 Vessels:** Aorta, Vena Cava, Pulmonary Artery, Pulmonary Vein ### The Heart's Chambers Diagram * The Diagram displays the **four chambers of the heart:** * Right atrium * Left atrium * Right ventricle * Left ventricle ## Flow of Blood ### Deoxygenated Blood: 1. Vena Cava 2. Right Atrium 3. Right AV Valve 4. Right Ventricle 5. Right SL Valve 6. Pulmonary Artery 7. Lungs ### Oxygenated Blood: 1. Pulmonary Vein 2. Left Atrium 3. Left AV Valve 4. Left Ventricle 5. Left SL Valve 6. Aorta 7. Body ## Diagram: The Heart * The diagram displays the heart with all four chambers and the major arteries and veins: * Superior vena cava * Inferior vena cava * Aorta * Pulmonary artery * Pulmonary vein * Right atrium * Left atrium * Right ventricle * Left ventricle * Tricuspid valve * Mitral valve * Pulmonary valve * Aortic valve * Pericardium