Science

• What is the definition of hemostasis?

  Hemostasis is the body's natural process to stop bleeding when a blood vessel is damaged.
• Why is hemostasis considered a protective mechanism?

  It prevents excessive blood loss and promotes healing.
• What are the main components involved in hemostasis?

  Blood vessels, platelets, and clotting factors.
• What is the primary aim of hemostasis?

  To maintain blood in a fluid state within blood vessels.
• What happens during hemostasis when a blood vessel is damaged?

  A clot rapidly forms to seal off the damaged blood vessel.
• What are the three main stages of hemostasis?

  Vascular spasm, platelet plug formation, and blood coagulation.
• What is the role of fibrin in blood clot formation?


  Fibrin forms long, sticky threads that create a mesh to trap blood cells and platelets, forming a stable clot.
• What happens during clot retraction?

  The clot shrinks, pulling the edges of the damaged vessel together.
• Why is it important that clotting factors remain inactive until needed?


  If clotting factors were always active, it could lead to unnecessary clot formation in blood vessels, potentially causing blockages.
• What is the first step in blood clot formation?

  Activation of clotting factors when blood vessels are damaged.
• What are the three pathways described in the clotting cascade?

  Intrinsic pathway, extrinsic pathway, and common pathway.
• In what form do clotting factors circulate in the blood?


  Clotting factors circulate in an inactive form until needed.
• What role does vitamin K play in blood clotting?


  Vitamin K is necessary for the production of several clotting factors.
• Where are blood clotting factors produced?

  They are produced mainly in the liver.
• How many main blood clotting factors are there?

  There are 13 main clotting factors, numbered I to XIII.
• What is the normal platelet count in the blood?

  Normal platelet count is about 150,000 to 450,000 per microliter of blood.
• Where are platelets produced in the body?

  Platelets are produced in the bone marrow.
• What is the function of platelets in hemostasis?

  Platelets adhere to damaged blood vessel walls, activate, aggregate to form a plug, and secrete substances that promote clotting.
• What are the main types of energy?

  • Kinetic
  • Potential
  • Thermal
  • Electrical
  • Chemical
  • Nuclear
• What does the Law of Conservation of Energy state?


  Energy cannot be created or destroyed, only converted from one form to another.
• How can energy be transferred?


  Energy can be transferred mechanically, electrically, by radiation, or by heating.
• What is electricity defined as?


  Electricity is the flow of electrical charge.
• How is voltage defined?


  Voltage is the electrical potential difference between two points, measured in volts (V).
• What does resistance measure in an electrical circuit?


  Resistance measures the opposition to the flow of current, measured in ohms (Ω).
• What is Ohm's Law formula?


  Ohm's Law states that V = IR, where V is voltage, I is current, and R is resistance.
• What is the mass number of an atom?


  The mass number is the sum of protons and neutrons in an atom.
• What are isotopes?


  Isotopes are atoms of the same element with different numbers of neutrons.
• What are forces in physics?


  Forces are pushes or pulls acting on an object.
• How are forces measured?


  Forces are measured in Newtons (N).
• What are contact and non-contact forces?


  Contact forces require physical contact (e.g., friction), while non-contact forces act at a distance (e.g., gravity).
• What are Newton's Laws of Motion?


  1. An object will remain at rest or in uniform motion unless acted upon by a force.
  2. Force = mass × acceleration (F = ma).
  3. For every action, there is an equal and opposite reaction.
• What is the formula for weight?


  Weight is calculated as W = mg, where g is gravitational field strength.
• What is the formula for calculating magnification?


  Magnification = Image size / Object size
• What does the magnification formula calculate?

  It calculates how much an object is enlarged
• If the image size is 10 mm and the object size is 1 mm, what is the magnification?


  $10x$
• How do you derive the magnification if the image size is 20 mm and the object size is 5 mm?


  Magnification = $\frac{20}{5} =$$4x$
• What is the magnification if the image size is 25 mm and the object size is 5 mm?


  5x
• If a scale bar on a microscope image is 5 mm and represents an actual object size of 0.5 mm, what is the image size?


  5 mm
• What does a scale bar of 8 mm represent if the actual object size is 2 mm?


  The image size is 8 mm
• What is the magnification if the image size is 15 mm and the object size is 3 mm?


  $5x$