Transport in Animals

  1. Circulatory System - A system of blood vessels with a pump and a valve to ensure one-way flow of blood.

  2. Single circulatory system - Blood passes through the heart only once to complete a full circuit through the body of the fish.

  3. Single Circulation of a Fish - The heart of a fish has two chambers; ventricle and atrium.
    Blood passes through the heart only once to complete a full circuit through the body of the fish.
    1. Deox blood from body capillaries -> 2. two-chambered heart -> 3. gill capillaries (oxygen into blood) -> 4. ox blood moves from gill cap to body capillaries
    Gill Circulation: when heart pumps blood to gills for oxygenation
    Systemic Circulation: when ox blood continues to the rest of the body until back at the heart

  4. Double circulatory system of Mammal - Mammalian hearts have 4 chambers.
    Blood passes thru heart twice for every one circuit of the body
    1. Deox blood enters right atrium via vena cava -> 2. moves into right ventricle thru tricuspid valve -> 3. deox blood pumped by right ventricle thru semilunar valve into pulmonary artery into lungs to become oxygenated by gas exchange -> 4. ox blood enters left atrium via pulmonary vein -> 5. ox blood moves into left ventricle -> 6. ox blood pumped by left ventricle to rest of body thru aorta ->7.  body cells use oxygen and causes blood to become deoxygenated
    Pulmonary circulation: when right side of heart receives deox blood from body and pumps it to lungs
    Systemic Circulation: when left side of heart receives ox blood from lungs and pumps to body 

  5. Advantages of double circulation - Mammals are larger than fish so have a greater requirement for oxygen and glucose for respiration. DC allows oxygen and glucose to be delivered faster and more efficiently through the blood since DC maintains higher blood pressure than SC

  6. Parts of heart - 1. Right Atrium - one of hearts 4 chambers
    2. Vena Cava - deox blood from body flows into RA via vena cava
    3. Tricuspid Valve - separates atria from ventricles, prevents backwards flow of blood
    4. Right Ventricle - chamber of heart
    5. Semilunar Valve in PA - prevents backwards flow of blood
    6. Pulmonary Artery - deox blood away from heart into lungs
    7. Septum - Seperates two sides of heart, prevents mixing of deox and ox blood
    8. Left Atrium - one of hearts 4 chambers
    9. Pulmonary Vein - ox blood from lungs flows into LA via pulmonary vein
    10. Bicuspid Valve - separates atria from ventricles, prevents backwards flow of blood
    11. Left Ventricle - chamber of heart with thickest walls
    12. Semilunar Valve in Aorta - prevents backwards flow of blood
    13. Aorta - carries deox blood away from heart to the body

  7. Coronary Arteries -  Supply blood to heart muscle, wrap around the outside of the heart

  8. Muscular Walls - The ventricles have thicker muscle walls than the atria since they pump blood out of heart at high pressures. LV has thicker wall than RV because it has to pump blood to whole body at high pressure while RV pumps to only lungs 

  9. Monitoring heart activity - Activity of heart can be monitored by ECG, pulse rate, listening to sounds of valves closing with stethoscope  

  10. Effect of physical activity on heart rate - during exercise, heart rate increases and may take several mins to recover because muscle cells of body need more energy; more oxygen and glucose for respiration, waste products of resp. also need to be removed quickly. Heart rate increases to meet these demands.  1. Record pulse rate
    2. Exercise for a while
    3. Record pulse rate every minute until it returns to resting rate 

  11. Coronary Heart disease - When the coronary artery becomes blocked, leading to blood (therefore oxygen) starvation in heart muscles. Leads to heart attack. Caused by buildup of cholesterol and other fatty substances within coronary arteries.
    Risk factors: diet, lack of exercise, stress, smoking, genetic disposition, age, gender.
    Risk can be reduced by: quit smoking, maintain healthy diet with reduced animal fats, exercise regularly

  12. Blood Vessels - tubes through which blood circulates in body. 3 types: arteries, veins, capillaries.

  13. Structure of arteries - 1. Carry blood away from heart
    2. Carry oxygenated blood except for PA
    3. Blood flows fast
    4. Thick muscular walls to withstand high blood pressures
    5. Artery walls have elastic fibres to stretch when blood passes thru
    6. Have a narrow lumen to maintain high blood pressures
    7. No valves since high blood pressures prevent backflow

  14. Structure of veins - 1. Carry blood away to heart
    2. Carry deoxygenated blood except for PV
    3. Blood flows slowly
    4. Thin muscular walls since low blood pressures
    5. Artery walls have little elastic fibres since low blood pressures
    6. Have a large lumen
    7. Valves to prevent backflow

  15. Capillaries - Role of capillaries is to provide an exchange of oxygen, nutrients, and waste products between blood and body’s cells. Structure is suited since only one cells thick, very thin permeable walls.

  16. Tissue fluid: fluid leaks out of capillaries and bathes the surrounding cells. useful substances such as oxygen diffuse out of blood in capillaries into tissue fluid then into cells. Waste products diffuse from body cells into tissue fluid and reabsorbed into blood in capillaries.

  17. Structure of capillaries - 1. smallest of blood vessels and connects arteries and veins. Arteries -> arteriole -> capillaries -> venule -> veins
    2. Carries both ox and deox blood
    3. Blood flows slowly at low pressure
    3. Walls are one cell thick, thin and permeable walls so substances can diffuse easily, blood plasma can leak out and form tissue fluid for diffusion
    5. Narrow lumen, wide enough for only 1 rbc to pass thru
    6. No valves

  18. Main blood vessels -  1. Vena Cava - deox blood from body to heart
    Aorta - ox blood away from heart to body
    2. Pulmonary Artery - deox blood from heart to lungs
    Pulmonary Vein - ox blood from lungs to heart
    3. Renal Artery - ox blood from heart to kidneys
    Renal Vein - deox blood from kidney to heart
    4. Hepatic Artery - ox blood from heart to liver
    Hepatic Vein - deox blood from liver to heart
    5. Hepatic Portal Vein - deox blood from digestive tract to liver

  19. Blood - Components of blood are: RBC, WBC, platelets, plasma

  20. Identifying - RBC: biconcave disc shape, dont have nucleus
    WBC: large cells with big nucleus 

  21. Red Blood Cells - contains a protein called hemoglobin which binds to oxygen, allowing it to be transported around the body to cells  

  22. White blood cells - fight off infections by carrying out phagocytosis and antibody production. 2 types. 1. Phagocytes: engulf pathogens in a process called phagocytosis. comes across a pathogen, engulfs it, releases digestive enzymes on it which digests and destroys it. Lobed nucleus, grainy cytoplasm 2. Lymphocytes - produces antibodies to attack and destroy pathogens. large, round nucleus, clear cytoplasm

  23. Platelets - fragments of cells present in blood that prevent blood loss by forming blood clots. clump together and form a plug to stop bleeding. the clot prevents pathogens from entering the blood vessel 

  24. Plasma - transports blood cells, ions, nutrients, urea, hormones, and carbon dioxide 

  25. Blood clotting - during the clotting process, the soluble protein fibrinogen is converted to fibrin, and insoluble protein, to form a mesh. Platelets stick to the mesh to form a scab and thereby preventing bleeding by blocking the cut.