LESSON 7: REGULATION OF BODY FLUIDS

• Plant


  A kingdom of life forms that include trees, herbs, bushes, grasses, vines, ferns, and mosses. They are the only life forms that can produce their own food using energy from sunlight.
• Animal


  A living thing that can move, eat and react to the world through its senses. Animals are multicellular, eukaryotic organisms that consume organic material, breathe oxygen, and can reproduce sexually.
• Body Fluids


  Liquids found within an organism that help with various functions. Can be classified into two major types according to location: intracellular fluid and extracellular fluid.
• Intracellular fluid


  The fluid that lies inside of the cell, sometimes referred to as cytoplasm.
• Extracellular fluid


  The fluid that is found outside of the cells.
• Plants


  • Use osmoregulation to regulate the fluids in their bodies
  • Plant cells depend on vacuoles to manage the osmolarity of their cytoplasm
  • Vacuoles help maintain water balance
  • Higher plants regulate water loss by the use of stomata on the underside of their leaves
• Osmoregulation in plants


  1. Plants adapt to different environments by utilizing stomata for water regulation

  2. Absorbing more water in hydrated soils

  3. Employing mechanisms like vacuole storage and thick cuticles to prevent water loss in semi-arid conditions
• Osmoregulation


  The process of maintaining salt and water balance (osmotic balance) across membranes within the body.
• Osmoconformers


  Organisms that try to match the osmolarity of their body with their surroundings. They conform either through active or passive means.
• Osmoconformers


  • Most marine invertebrates such as starfish, jellyfish and lobsters
• Osmoregulators


  Organisms that actively regulate their osmotic pressure, independent of the surrounding environment.
• Osmoregulators


  • Many vertebrates, including humans
  • Most freshwater fish
• Homeostasis


  The generally stable state that exists within an animal's body. Internal conditions that are maintained homeostatically are blood glucose levels, body temperature, and calcium levels in the blood stream.
• Thermoregulation


  A process that allows your body to maintain its core internal temperature.
• Ectotherms


  Animals that have a body temperature that is the same as their surroundings. They are classified as cold-blooded.
• Endotherms


  Animals that maintain their body temperature at a constant level despite changes in their surrounding environment.
• Excretion


  The process by which organisms expel metabolic waste products and other toxic substances from their body.
• Similarities between plants and animals

  • Cannot move around
  • Both rely on osmoregulation
  • Both need to maintain a stable internal environment
  • Rely on passive processes
• Differences between plants and animals


  • Plants cannot move around
  • Animals can move around
  • Plants have specialized tissues
  • Animals have a circulatory system
  • Plants have excretory system
• Excretory system in humans

  • Consists of the kidneys, ureters, bladder and urethra
  • Water is filtered from the blood and stored as urine in each kidney
  • Urine leaves the kidneys by ureters and stored in the bladder
  • The bladder can distend to store urine that eventually leaves through the urethra
  • The nephron is the functional unit of kidney
• Structure of nephron


  • Nephrons are the "functional units of the kidney, they cleanse the blood of toxins and balance the constituents of the circulation to homeostatic set points through the processes of filtration, reabsorption, and secretion.
• Excretion in plants


  • Gaseous wastes, oxygen, carbon dioxide, and water vapor are removed through the stomata of leaves and lenticels of stems
  • Some waste products collect in the leaves and bark of trees
  • When the leaves and bark are shed, the wastes are eliminated