The blood

• What are the four main components of blood?

  Red blood cells, white blood cells, platelets, plasma
• What is the role of red blood cells?

  • Carry oxygen from lungs to tissues
  • Contain hemoglobin for oxygen transport
  • Form oxyhemoglobin to deliver oxygen
• What is hemoglobin's function in red blood cells?

  It combines with oxygen to form oxyhemoglobin
• What happens to oxyhemoglobin in tissues?

  It splits back into hemoglobin and oxygen
• What are the two adaptations of red blood cells?

  They lack a nucleus and are biconcave
• Why do red blood cells lack a nucleus?

  To provide more space for hemoglobin
• What shape do red blood cells have and why?

  They are biconcave for a large surface area
• What percentage of blood do white blood cells make up?

  Less than 1%
• What are the functions of white blood cells?

  • Defend against infection
  • Engulf microorganisms (phagocytosis)
  • Produce antibodies to destroy pathogens
  • Produce antitoxins to neutralize toxins
• What is phagocytosis?

  Engulfing or consuming microorganisms
• Do white blood cells have a nucleus?

  Yes, they have a nucleus
• What are platelets and their function?

  Fragments of cells that aid in clotting
• What do platelets do when there is a cut?

  They rush to the wound and clot
• Why are platelets important?

  To stop blood loss and prevent infection
• What is plasma and its role in blood?

  • Pale straw-colored liquid
  • Makes blood watery for flow
  • Carries red/white blood cells and platelets
  • Transports nutrients, waste, hormones, proteins
• What is the average blood volume in adults?

  About 5 liters
• What happens if blood volume drops too much?

  Insufficient oxygen delivery to tissues
• What are the two types of blood replacement?

  1. Artificial blood:

  • Saltwater substitute
  • Adds volume but no red blood cells

  1. Blood transfusion:

  • Real blood from donors
  • Contains red blood cells for oxygen transport
• What is the main benefit of artificial blood?

  It adds volume to the circulatory system
• What is a limitation of artificial blood?

  It cannot transport oxygen effectively
• What is the key advantage of a blood transfusion?

  It provides real red blood cells
• Where can you find more educational resources?

  • Cognito.org for videos
  • Questions and flashcards
  • Exam style questions and past papers
  • Progress tracking for study