CIRCULATORY SYSTEM

• Gas Exchange


  Animals take in oxygen and release carbon dioxide, plants utilize carbon dioxide and release oxygen
• Gas Exchange in Plants

  • Leaves obtain oxygen through stomata, stems and roots also take in oxygen
  • Structures include stomata, lenticels, root hairs, pneumatophores
• Gas Exchange in Animals

  • Respiratory surfaces/organs differ in invertebrates and vertebrates

  
• Gas Exchange in Humans

  • Blood circulation maintains oxygen/carbon dioxide concentration gradient
  • Oxygen carried by haemoglobin in red blood cells

  
• Transport & Circulation


  Circulatory system transports nutrients, oxygen, and removes waste in plants and animals
• Transport in Plants


  • Absorption of water through roots, up and down movement in phloem
• Circulation in Animals


  • Animals must have nutrients and oxygen reach every cell, and waste removed
• Regulation of Body Fluids

  Hydrophytes absorb water across entire surface, animals use excretory system to control water loss and maintain osmotic pressure
• How animals excrete wastes

  Kidneys
• How plants excrete wastes
• Respiratory surfaces or organs in invertebrates

  • Integumentary exchange
  • External gills
  • Tracheal system in arthropods
• Integumentary exchange


  The general body surface or skin used by animals with high surface-to-volume ratio
• Animals using integumentary exchange

  • Flatworm
  • Earthworm
• Amphibians


  Use their moist skin in addition to lungs as gas exchange surface
• External gills


  Used by invertebrates that live in aquatic habitats, highly folded, thin-walled, vascularized epidermis that project outward from the body
• Crustaceans and mollusks


  Utilize internal gills
• Tracheal system in arthropods

  Utilizes fine air-conducting tubules to provide gaseous exchange at the cellular level, not dependent on a circulatory system
• Arthropods with tracheal system

  • Insects
  • Spiders
• Respiratory organs in vertebrates


  • External gills
  • Internal gills
  • Lungs
• External gills


  Thin, vascular projections from the body surface of a few amphibians, e.g. larval salamander
• Internal gills


  Rows of slits or pockets in adult fishes positioned at the back of the mouth such that water that enters the mouth can flow over them as it exits just behind the head
• Water flows over the gills and blood circulates through them in opposite direction, called countercurrent flow, which is highly efficient in extracting oxygen from water
• Lungs


  Internal respiratory surfaces shaped as a cavity or sac, provide a membrane for gaseous exchange, require a circulatory system to transport gases to the rest of the body
• Types of circulation


  • Pulmonary circulation
  • Systemic circulation
  • Coronary circulation
• Pulmonary circulation


  Moves blood to and from the lungs, carries oxygen-poor blood from the heart to the lungs, and carries oxygen-rich blood from the lungs to the left atrium of the heart
• Systemic circulation


  Provides the functional blood supply to all body tissues, carries oxygen and nutrients to the cells and picks up carbon dioxide and waste products
• Coronary circulation


  Circulation of blood in the blood vessels that supply the heart muscle (myocardium), coronary arteries supply oxygenated blood to the heart muscle, and cardiac veins drain away the deoxygenated blood
• Types of excretory organs in animals

  • Cell surface or cell membrane
  • Contractile vacuole
  • Malpighian tubules
  • Nephridia
  • Protonephridia or Flame Bulb System
  • Metanephridia
• Protonephridia or Flame Bulb System

  A network of tubules that lack internal openings but have external openings at the body surface called nephridiopores
• Metanephridia


  The excretory tubule of most annelids and adult mollusks, with a funnel-like internal opening called a nephrostome that collects body fluids
• Malpighian Tubules


  The excretory tubules of insects and other terrestrial arthropods attached to their digestive tract (midgut), they do not filter body fluids but employ secretion to generate the fluid for release from the body
• Types of animals based on osmolarity

  • Osmoconformers
  • Osmoregulators
• Osmoconformers


  Allow the osmolarity of their body fluids to match that of the environment, expend little or no energy on maintaining water balance
• Osmoregulators


  Keep the osmolarity of body fluids different from that of the environment, expend more energy
• Nitrogenous wastes


  • Ammonia
  • Urea
  • Uric Acid
• Ammonia


  The primary nitrogenous waste for aquatic invertebrates, the most toxic nitrogen-containing compound
• Urea


  Commonly produced by terrestrial animals, less toxic than ammonia
• Uric Acid


  Excreted by birds, insects, and terrestrial reptiles, relatively nontoxic but more energetically expensive to produce than urea