bio

• Mass transport systems


  • Exchange surfaces to get materials into and out of the transport system
  • A system of vessels that carry substances - these are usually tubes, sometimes following a very specific route, sometimes widespread and branching
  • A way of making sure that substances are moved in the right direction (e.g., nutrients in and waste out)
  • A way of moving materials fast enough to supply the needs of the organism - this may involve mechanical methods such as the pumping of the heart or ways of maintaining a concentration gradient so that substances move quickly from one place to another (e.g., using facilitated diffusion and active transport)
  • A suitable transport medium (e.g., fluid)
  • In many cases, a way of adapting the rate of transport to the needs of the organism
• Cells require a supply of chemical substances such as glucose and oxygen for cellular respiration
• Respiration supplies energy and produces the toxic waste product carbon dioxide
• These substances must be transported from outside of a large organism into the cells
• In multicellular animals, many chemical reactions take place inside every microscopic cell
• This and other products need to be removed from the cells before they cause damage to them
• Endocrine glands include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands (including the adrenal medulla), pancreas, ovaries/testes, and pineal gland.
• Lymph


  Watery liquid that passes from the tissue fluid into the lymphatic system
• Tissue fluid

  1. Most of the water from tissue fluid reenters capillaries by osmosis

  2. Some fluid passes into the lymphatic system
• Lymph nodes

  • Contains white blood cells that are important in destroying harmful bacteria
• Lacteals


  Carry fats from the small intestine
• A person gets an infection


  One of the first signs may be swelling of the lymph nodes, often referred to as swollen glands
• Lymphatic system


  Part of the lymphatic system
• Tissue fluid


  Watery liquid that forms between the capillaries and the cells
• Lymph nodes

  Swellings called lymph nodes, which contains white blood cells that are important in destroying harmful bacteria
• Lymph

  1. Filtered in lymph nodes

  2. Transported back to the blood by opening into the subclavian veins
• Lymphatic capillaries


  Vessels similar to blood capillaries that transport the fluid, lymph, back to the blood