What is it?
blood vessels
What is it?
heart
What is it?
esophagus
What is it?
stomach
What is it?
intestine
What is it?
mouth
What is it?
lungs
What is it?
nose
What is it?
trachea
What is it?
bladder
What is it?
kidneys
What is it?
urethra
Which SYSTEM is it?
the respiratory system
Which SYSTEM is it?
the circulatory system
Which SYSTEM is it?
the digestive system
Which SYSTEM is it?
the excretory system
