Systems in Animals

• Animals have different organ systems, a system is a group of parts that work together
• A vertebrate's bones make up it's skeletal system

 

• it is a frame that supports the body and protects organs
• the muscular system works with the skeletal system.  it is made of strong tissues.
• the muscles shorten and pull on the bones to make the animal move
• invertebrates move by muscular systems alone

 

• the master control system of the body is the nervous system, it is made of nerve cells
• invertebrates have simple nervous systems, vertebrates have complicated ones, mammals are the most complex.
• millions of nerve cells join together in mammals to form nerves
• the brain and sense organs help animals see, hear, taste, touch, and smell

 

• all animal cells need oxygen
• the respiratory system brings oxygen to the blood and removes wastes like CO2
• larger animals use gills or lungs to exchange gasses with the water or air
• the circulatory sustem moves blood through the body.
• blood carries oxygen, food, and water to body cells and removes wastes.
• the heart is the main organ of the circulatory system
• an amphibian heart has 3 chambers, a fish has 2, mammals and birds have 4, sponges and cnidarians have no heart or circulatory system

 

• the excretory system removes waste (kidney, liver, bladder, skin, lungs)
• Animals take in food for energy
• the digestive system breaks food down
• segmented worms have digestive systems with 2 openings. Food enters the mouth, and wastes exit through the tail end
• Mammals stomach's churn and mix food, digestive juices break it down.  The food bits travel to the small intestine where they are absorbed by the blood to carry to the body.