2.6.8 Organs and Organ Systems in Animals

• An organ system is a number of organs working together to carry out an overall life function.
• There are 11 organ systems in the human body:

  1. the digestive system
  2. the circulatory system
  3. the respiratory system
  4. the urinary system
  5. the integumentary system
  6. the musculo-skeletal system
  7. the immune system
  8. the nervous system
  9. the endocrine system
  10. the reproductive system
  11. the lymph system
• There are 5 main organs involved in the digestive system:

  1. the oesophagus
  2. the stomach
  3. the intestines and other associated glands
  4. the liver
  5. the pancreas
• The digestive system carries out the life process: nutrition to provide ATP and materials for growth and repair.
• There are 2 main organs/tissues in the circulatory system:

  1. the heart
  2. the blood vessels
• The circulatory system carries out the transport to and from cells.
• There are 3 main organs/tissues in the respiratory system:

  1. the airways and the lungs
  2. the diaphragm
  3. the intercostal muscles
• The respiratory system carries out:

  1. breathing
  2. gaseous exchange
  3. excretion
• There are 3 main organs/tissues involved in the urinary system:

  1. the kidneys
  2. the ureters
  3. the bladder
• The urinary system carries out:

  1. osmoregulation
  2. excretion
• There are 3 main organs/tissues involved in the integumentary system:

  1. the skin
  2. the hair
  3. the nails
• The integumentary system carries out:

  1. waterproofing
  2. protection
  3. temperature regulation
• There are 2 main organs/tissues involved in the musculo-skeletal system:

  1. the skeleton
  2. the skeletal muscles
• The musculo-skeletal system provides:

  1. support
  2. protection
  3. movement
• There are 5 organs/tissues involved in the immune system:

  1. the bone marrow
  2. the thymus gland
  3. the skin
  4. the stomach acid
  5. the blood
• The immune system provides protection against pathogens.
• There are 3 main organs/tissues involved in the nervous system:

  1. the brain
  2. the spinal cord
  3. the nerves
• The nervous system ensures:

  1. communication
  2. control
  3. coordination
• The endocrine system involves the glands that make hormones, e.g :

  1. the thyroid
  2. the ovaries
  3. the testes
  4. the adrenals
• Like the nervous system, the endocrine system ensures:

  1. communication
  2. control
  3. coordination
• There are 5 main organs/tissues involved in the reproductive system:

  1. the testes
  2. the penis
  3. the ovaries
  4. the uterus
  5. the vagina
• The lymph system involves the lymph nodes and vessels.
• The lymph system transports fluid back to the circulatory system and is also important in resisting infections.
• The skin is the body's largest organ.

  Within it, there are other smaller organs, such as hair follicles.