specialised cells

• Specialised animal cells


  • Have components that allow them to complete a specific purpose
• Specialised animal cells


  • Red blood cells
  • Sperm cells
  • Egg cell
  • Nerve cells
  • Muscle cells
  • Ciliated cells
  • Villi
• Red blood cells


  Carry oxygen around the body, which is needed for respiration
• Red blood cells


  • Contain haemoglobin which carries oxygen molecules
  • Don't have a nucleus, allowing more space to carry oxygen
  • Flat disc shape with dips on both sides (biconcave) which gives them a large surface area
• Sperm cells


  The male sex cell, join with an egg cell during fertilisation to form an embryo
• Sperm cells


  • Have a tail to move them towards an egg cell
  • Have many mitochondria to release energy for movement
  • Have an acrosome part at the tip of the head that releases enzymes to digest the egg membrane
  • Have a haploid nucleus containing the genetic material for fertilisation
  • Produced in large numbers to increase the chance of fertilisation
• Egg cell


  The female sex cell, joins with a sperm cell during fertilisation to form an embryo
• Egg cell


  • Cytoplasm contains nutrients for the growth of the early embryo
  • Haploid nucleus contains genetic material for fertilisation
  • Cell membrane changes after fertilisation by a single sperm so that no more sperm can enter
• Nerve cells


  Transmit electrical signals in the nervous system
• Nerve cells


  • Thin and can be more than one metre long to carry messages up and down the body quickly
  • Have branched connections at each end to join to other nerve cells and pass messages
  • Have a fatty (myelin) sheath that surrounds them to increase the speed of the electrical signal
• Muscle cells


  Found in bundles which make up our muscles, able to contract (get shorter) and relax (return to original length)
• Types of muscle cells

  • Cardiac (heart) muscle cells
  • Smooth muscle cells
  • Skeletal muscle cells
• Cardiac muscle cells


  • Contract and relax to pump blood around our bodies for our entire lives, never get tired
• Smooth muscle cells


  • Make up thin sheets of muscle, such as the stomach lining, can also be arranged in bundles or rings like the anus
• Skeletal muscle cells


  • Joined to bones, contract to make bones move and joints bend
• Ciliated cells


  Found in the airways, have tiny hairs on their tops called cilia which beat in a rhythm to move mucus containing dust and other particles upwards and out of the airways
• Ciliated cells


  Also found in the oviducts, where the tiny hairs beat to move the egg from the ovaries to the uterus
• Villi


  Structures about one millimetre long in the small and large intestines, millions of them poke out to absorb digested food and water into the blood
• Villi


  • Have a large surface area
  • Have thin walls which are only one cell thick
  • Have tiny hairs on the cells of the lining to absorb more food and water