SCIENCE - Howard

• Double Circulating


  Blood is pumped from the right side of the heart to the lungs, and the oxygenated blood that returns is pumped from the left side of the heart to the body
• Blood flow through the heart

  Vena cava - right atrium - pulmonary artery - out to lungs to collect oxygen - back to heart through pulmonary vein - left atrium - left ventricle - aorta
• Vena cava


  Carries deoxygenated blood to the heart
• Pulmonary artery


  Carries deoxygenated blood from the right side of the heart to the lungs
• Pulmonary vein


  Carries oxygenated blood from the lungs to the left side of the heart
• Aorta


  Carries oxygenated blood from the left side of the heart to supply the body
• Hepatic portal vein


  Carries digested food from the small intestine to the liver
• Renal vein


  Carries deoxygenated blood back to the heart
• Pulmonary artery


  Blood vessels that carry oxygen-poor blood from the right side of the heart to the lungs
• Pulmonary vein


  Blood vessels that transfer freshly oxygenated blood from the lungs to the left atrium of the heart
• Blood components


  • Red blood cells
  • White blood cells
  • Plasma
  • Platelets
• Red blood cells


  Carry oxygen from the lungs and deliver it throughout the body
• White blood cells


  Help the body fight off infections and other diseases
• Plasma


  Transports nutrients, hormones and proteins to necessary processes in the body
• Platelets


  Form clots to stop or prevent bleeding
• Blood vessels


  Tubes that transport blood throughout the human body
• Types of blood vessels

  • Arteries
  • Veins
  • Capillaries
• Arteries


  Carry high-pressure blood away from the heart
• Veins


  Carry blood to the heart
• Capillaries


  Have thin walls which are leaky, allowing substances to leave the blood and reach the body's tissues
• Coronary artery supplies the heart cells themselves with oxygenated blood
• Coronary heart disease


  When the coronary artery narrows due to fatty cholesterol build up in the walls
• Treatments for coronary heart disease

  • Stents - surgery to insert mesh to hold artery open
  • Statins - medicine to lower blood cholesterol
• Xylem


  Tightly packed cells with lots of chloroplasts to absorb as much sunlight as possible, adapted for transporting water and minerals
• Phloem


  Transports glucose (food) from the leaves to the rest of the plant
• Transpiration


  Loss of water as it is pulled in from the roots to the leaves and lost through the stomata on the bottom of the leaf
• Factors affecting transpiration


  • Temperature
  • Light intensity
  • Humidity
  • Wind speed
• Stomata


  Holes found on the bottom of leaves that allow gas exchange
• Guard cells


  Control the opening and closing of the stomata
• Leaves have a waxy cuticle on the upper epidermis to help water run off
• Leaves have a diagonal vein pattern to help water run off into the soil
• Leaves have a midrib vein for support and to transport minerals and water
• Leaves have a hollow inside to allow gases to diffuse
• The palisade mesophyll is where most photosynthesis takes place
• The spongy mesophyll has air spaces to allow gas exchange
• The lower epidermis contains the stomata
• The upper epidermis provides structural support for the whole transport system
• The waxy cuticle on the upper epidermis helps prevent water loss
• Pulmonary circulation


  Blood flow from the right ventricle to the lungs and back to the left atrium
• Systemic circulation


  Blood flow from the left ventricle to the body and back to the right atrium