Week 3-4 (2nd Part)

• The main transport system for animals is the circulatory system
• The circulatory system's main functions are to transfer the nutrients and oxygen to all body cells and to transport waste products to the liver, kidneys and lungs
• diffusion only occurs over short distances such as between blood and air in the lungs.
• diffusion — the movement of molecules from an area of high concentration to an area of low concentration
• Bulk flow is the movement of the blood from an area of high pressure to an area of low pressure through the action of the heart that pumps the blood and pressurizes it to flow.
• The heart is the muscle that pumps blood throughout the body. I
• The heart consists of four chambers, the top two chambers are called atria while the bottom two are called ventricles.
• Label the parts

  A) Anterior Vena Cava

  B) Capillaries of head and forelimbs

  C) Pulmonary Artery

  D) Capillaries of right lung

  E) Pulmonary Artery

  F) Capillaries of left lung

  G) Pulmonary Vein

  H) Left Atrium

  I) Left ventricle

  J) Aorta

  K) Capillaries of abdominal organs and hind limbs

  L) Posterior Vena cava

  M) Right Ventricle

  N) Right Atrium

  O) Pulmonary Vein

  
• Blood flows into the right atrium from the venae cavae and then passes through the tricuspid valve into the right ventricle. The right ventricle contracts and forces blood out through the pulmonary semilunar valves into the pulmonary arteries which carry the blood to the lungs where oxygenation takes place.
• The blood from the circulation enters the right atrium while the reoxygenated blood from the lungs enters the left atrium.
• After being oxygenated, the blood returns to the heart via the pulmonary veins and enters the left atrium. It then passes through the bicuspid or mitral valve into the left ventricle. The left ventricle contracts and forces blood out through the aortic semilunar valves into the aorta which carries the blood to all other parts of the body.
• Label this:

  A) Aorta

  B) Superior vena cava

  C) Right atrium

  D) tricuspid valve

  E) pulmonary valve

  F) Right Ventricle

  G) septum

  H) left ventricle

  I) aortic valve

  J) mitral valve

  K) left atrium

  L) Pulmonary Vein

  M) Pulmonary Artery

  
• atria are thin-walled chambers because they need to contract only minimally to blood into the ventricles.
• ventricles have thicker walls because they need to contract harder to pump blood out of the heart and in to the circulation
• The right ventricle pumps blood into the pulmonary trunk while the left ventricle ejects blood into the aorta.
• The delivery system of the heart is separated into two circuits: the pulmonary and the systemic circuits.
• pulmonary circuit - supplied by the right side of the heart, receives the returning blood and pumps the blood to the lungs for reoxygenation and dispatch of carbon dioxide
• systemic circuit - supplied by the left side of the heart, transports the oxygenated blood to the entire body
• Blood Vessels - are responsible for the transport of blood throughout the body.
• There are three types of blood vessels: arteries, veins, and capillaries.
• Arteries - carry oxygenated blood away from the hear
• veins - carry deoxygenated blood towards the heart.
• Capillaries - are tiny, thinwalled vessels that allow water, nutrients, and oxygen from the blood to move to the surrounding tissues and allow wastes to move out in the opposite direction.
• Blood - is a special connective tissue that distributes essential nutrients, including oxygen while collecting wastes, such as carbon dioxide
• plasma - yellowish fluid, which contains red blood cells, white blood cells, and platelets.
• hemoglobin - the protein that transports oxygen to the different tissues in the body. This protein also releases the carbon dioxide picked up from body tissues.
• Circulation of the blood throughout the heart

  1. Superior Vena cava
  2. right atrium
  3. tricuspid valve
  4. right ventricle
  5. pulmonary valve
  6. pulmonary artery
  7. lungs
  8. Left Atrium
  9. Left Ventricle
  10. Aorta
  11. rest of the body
• Closed circulatory system


  The circulatory fluid or blood is limited within vessels. The heart pumps blood into large vessels, branching into smaller vessels and into different organs. Other animals with closed circulatory system include squids and earthworms. Humans have also a closed circulatory system
• Open Circulatory System


  The circulatory fluid called haemolymph coats the body cells. The heart pumps the haemolymph through circulatory vessels and goes into the sinuses or the spaces surrounding the organs. Arthropods such as grasshoppers have open circulatory systems.
• Haemolymph - Coats the body cells
• Pulmonary circulation promotes the external respiration process.
• Deoxygenated blood flows into the lungs. This absorbs oxygen from tiny air sacs (the alveoli) and releases to exhale carbon dioxide
• Systemic circulation makes internal respiration easier: oxygenated blood passes through the rest of the body to capillaries. The blood diffuses oxygen into cells and absorbs carbon dioxide
• Osmoregulation is the active regulation of body fluids and ion balance in an organism.
• Plants have no specific osmoregualtory organs however, they have stomata below their leaves that regulate the amount of water loss.
• kidneys play a great role in osmoregulations.
• Animals that permit the osmolarity of their body fluids to fit that of the environment are called Osmoconformers
• Ammonia, urea and uric acid are the nitrogenous wastes expelled by animals. These are all toxic to cells.
• Ammonia


  Are very poisonous to cells and excreted by aquatic invertebrates, teleosts, and larval amphibians.
• Urea


  Are excreted down mainly in the urine of mammals