General Biology 2

• Transport mechanism in invertebrates

  • without circulatory system
  • with circulatory system
• without circulatory system 


  hydras and planarias
• with circulatory system

  • open circulatory system
  • closed circulatory system
• hemolymph


  is present instead of blood.
• open circulatory system


  present in arthropods and mollusks.
• Circulatory pathways in vertebrates

  • single-loop
  • double-loop
• single loop is common in fishes, heart has a single atrium and a single ventricle.
• double loop has a systemic and pulmonary circuits.
• heart is coned-shape muscular organ about the size of a fist.
• heart is located behind the sternum and tilted to the left.
• pathway of the blood from the body through the human heart is controlled by the different valves.
• pulmonary circuit collects oxygen-poor blood from all parts of he body to the lungs.
• systemic circuit carries oxygen-rich blood from the lungs throughout the body.
• plasma of the blood is about 55% of the whole count of the blood in the human body. it contains proteins involved in buffering the blood.
• red blood cells contain hemoglobin which makes it red in color
• granulocytes consists of 3 phils

  • neutrophils
  • eosinophils
  • basophils
• agranulocytes - the monocytes are the largest know leukocytes which are large phagocytic macrophages.
• lymphocytes have a distinct role in adaptive immunity because of T-cells and B-cells
• platelets are known for its important function in blood clotting.
• capillary exchange 3 phases

  • filtration
  • no net movement
  • reabsorption
• circulatory system is responsible for the movement of fluids between various parts of the body.
• blood is present in a closed system