adaptations

• How is the small intestine adapted for efficient absorption? -BLTVM

  • Good blood supply - has many capillaries which maintains the concentration gradient.
  • Large surface area - due to the villi and this helps absorption as there is more space for particles to move through;.
  • Thin walls - villi and capillary walls that are one cell thick - for shorter diffusion distance.
  • Very long - increasing absorption time.
  • Many mitochondria for aerobic respiration to release energy for active transport.
• How are red blood cells adapted?

  • Tiny - allowing them to pass through the narrow capillaries.
  • Biconcave shape - Gives it a large surface area for fast oxygen diffusion.
  • No nucleus - Allows more space for haemoglobin, increasing oxygen carrying capacity.
• How are white blood cells adapted?

  • Flexible : to move through capillary walls into the tissues.
• How are the lungs adapted for gas exchange? - BLTVM

  • Blood supply - maintains the concentration gradient.
  • Large surface area - due to the alveoli which helps, more space for particles to move.
  • Thin - shorter diffusion distance.
  • Ventilation - maintains the concentration gradient.
  • Moist - which allows oxygen and carbon dioxide to dissolve.
• What are the types of blood cells?

  • Platelets
  • Plasma
  • White blood cells
  • Red blood cells
• What do red blood cells do?

  Transport oxygen using haemoglobin.
• What do platelets do?

  Help with blood clotting.
• What does plasma do?

  • Transports nutrients/hormones/antibodies
  • Regulates body temperature by distributing heat
• What are the types of white blood cells?

  • Phagocytes - engulf and digest pathogens through phagocytosis.
  • B lymphocytes - create antibodies to target specific pathogens
  • T lymphocytes - destroy infected cells and activate B cells.