This system gives your body shape and support.
the skeletal system
This muscle on the front of your upper arm helps you bend your elbow.
Bicep
You breathe this gas into your lungs.
oxygen
Digestion begins in this part of the body.
the mouth
This organ controls the body.
the brain
This part of the skeleton protects your brain.
Skull
This muscle on the back of your upper arm helps straighten your arm.
tricep
These tiny air sacs in the lungs exchange gases.
alveoli
This organ absorbs nutrients from food.
the small intestine
These cells carry messages through the nervous system.
neurons
These protect your heart and lungs.
ribs
These muscles in your stomach area help you bend and twist.
Abdominal muscles (abs)
This muscle below the lungs helps you breathe.
the diaphragm
This organ makes bile to help digest fats.
the liver
This protects the brain and spinal cord.
the skull and vertebrae
This is the longest bone in your body
femur
These large muscles in the front of your thigh help you kick and run.
Quadriceps
This tube carries air from your throat to your lungs.
the trachea
This organ churns and mixes food with acid.
the stomach
This part of the nervous system sends messages between the brain and body.
the spinal cord
This tissue connects bones to other bones.
ligaments
These chest muscles help move your arms and are often called “pecs.”
Pectoral muscles
Your body removes this waste gas when you exhale.
carbon dioxide
This long tube connects the mouth to the stomach.
Esophagus
This reaction happens quickly and automatically.
a reflex