9.1 Blood

• What are the components of blood?

  Blood is composed of red blood cells, white blood cells, platelets, and plasma.
• Know the function of each component in blood.

  red blood cells: they transport oxygen in blood using haemoglobin around the body.

  white blood cells: they help destroy the microorganisms that cause infectious diseases and help to keep our bodies healthy.

  platelets: they produce a tangle of protein strands that trap red blood cells and form blood clots to prevent loss of blood and to prevent infection.

  plasma: to transport blood cells and dissolved nutrients and waste around the body.
• Describe how the blood helps cells to get nutrients & remove waste.

  Blood carries nutrients and oxygen to cells through its plasma. These substances diffuse from the bloodstream into the cells, providing nourishment. Waste products, like carbon dioxide, diffuse from the cells into the bloodstream for removal by organs like the lungs or kidneys.
• Identify each component of the blood.

  1. Red blood cells: Carry oxygen and carbon dioxide.
  2. White blood cells: Fight infection and disease.
  3. Platelets: Help in blood clotting.
  4. Plasma: Liquid portion of blood, carries nutrients, hormones, and waste products.
• What are capillaries?

  Capillaries are tiny blood vessels that connect arteries to veins. They're microscopic in size and allow for the exchange of nutrients, oxygen, and waste products between the bloodstream and tissues.
• Know that capillaries exchange substances with cells

  Capillaries are small blood vessels that facilitate the exchange of nutrients, oxygen, and waste products between the bloodstream and individual cells in tissues.
• Describe how exchange occurs in cells

  Exchange with cells occurs as substances like oxygen and nutrients diffuse from the capillaries into the surrounding tissues, while waste products such as carbon dioxide diffuse from the tissues into the capillaries for removal.