Bio test p1

• Micrograph


  A photograph taken using a microscope, showing a magnified view of an item
• Types of micrographs


  • Light micrograph
  • Electron micrograph
• Electron microscope


  • Has better resolution
  • Organelles are seen more clearly
• Organelle


  Cell structures that are depicted in more detail in updated micrographs compared to previous depictions
• Nucleus


  • Controls the activities of the cell
  • Where DNA is made
• Diffusion


  The distribution of particles from an area of high concentration to an area of low concentration, until they are evenly distributed
• Particles move gradually from an area of high concentration to an area of low concentration, in a random way due to the random motion of the particles
• Concentration gradient


  The difference in concentration between two areas, which drives the net movement of particles from the high concentration to the low concentration area
• Particles will move in a particular direction until they are evenly distributed (reach equilibrium)
• Circulatory system


  A means of transport within the human body
• What is transported by the circulatory system

  • Dissolved food particles
  • Oxygen
  • Nitrogenous waste
  • Carbon dioxide
  • Hormones
  • White blood cells
  • Red blood cells
  • Platelets
  • Heat
  • Water
• Components of the circulatory system

  • Heart
  • Blood vessels (arteries, veins, capillaries)
  • Blood
• Blood


  A special example of a mixture - a solution with solids suspended in it
• What is in blood

  • Plasma (water containing dissolved substances)
  • Suspended blood proteins and cells (red blood cells, white blood cells, platelets)
• Red blood cells

  Contain haemoglobin, which transports oxygen
• Haemoglobin


  A protein that contains iron and combines easily with oxygen, allowing it to be transported and released where needed
• Carbon dioxide transport


  Transported dissolved in blood plasma as carbonate, and by haemoglobin
• Food materials


  Dissolved in plasma and transported from the small intestine to the liver and then to the rest of the body
• Waste (urea)


  Made in the liver and transported in the plasma to the kidneys to be excreted in urine
• Hormones


  Made in endocrine glands and secreted into the bloodstream to be transported around the body
• Heat transport


  Heat produced by the liver and muscles is transported away from these areas to be distributed throughout the body
• Blood clotting


  Platelets release molecules into the blood to turn on clotting factors when a blood vessel is injured, to prevent excessive bleeding
• Skin


  The first line of defense, being impermeable with pores containing substances that can destroy bacteria/viruses
• White blood cells


  • Lymphocytes
  • Phagocytes
• Lymphocytes


  Identify foreign bodies and stimulate the production of antibodies
• Phagocytes


  Recognize, engulf, digest and kill foreign matter
• The circulatory system transports substances to and from the cells, tissues, and organs of the body
• The heart pumps blood around the body
• Blood vessels are the means by which blood gets around the body
• Blood is a mixture/solution with solids suspended in it
• Oxygen is transported from the lungs to the left side of the heart, then around the body by red blood cells
• Carbon dioxide is transported from the blood to the lungs
• Blood clots to prevent excessive bleeding when a blood vessel is injured
• The heart is divided into left and right sides, with four chambers (two atria and two ventricles)
• Cardiac cycle

  1. Diastole (heart muscle relaxes)

  2. Atrial systole (atria contract)

  3. Ventricular systole (ventricles contract)
• Arteries


  Carry blood away from the heart
• Veins

  Carry blood towards the heart
• Capillaries


  Carry blood towards the heart
• Blood pressure


  The force exerted on the walls of the blood vessels by the blood
• Foreign


  Anything the immune system identifies as non-self