This organ pumps blood throughout your body.
Heart
These two organs are responsible for breathing.
Lungs
This organ controls thinking, memory, and movement.
Brain
This framework supports the body and protects organs.
Skeleton
This is the body's largest organ.
Skin
These blood vessels carry blood away from the heart.
This muscle beneath the lungs contracts during inhalation.
Diaphragm
These specialized cells transmit nerve signals.
Neurons
This is the longest bone in the human body.
Femur
These organs filter blood and produce urine.
Kidneys
The human heart has this many chambers.
Four
This tube is commonly called the windpipe.
Trachea
The brain and spinal cord make up this division of the nervous system.
CNS (central nervous system)
These structures connect muscle to bone.
Tendons
This organ produces bile.
Liver
This chamber pumps blood into the aorta.
Left Ventricle
These tiny air sacs are where gas exchange occurs.
Alveoli
This brain region helps coordinate balance and movement.
Cerebellum
These structures connect bone to bone at joints.
Ligaments
Most nutrient absorption occurs in this part of the digestive tract.
Small intestine
This natural pacemaker normally starts the heartbeat.
Sinoatrial node, or SA node
This substance reduces surface tension and helps keep alveoli open.
Pulmonary Surfactant
This insulating covering helps nerve impulses travel faster along many axons.
Myelin sheath
These bone cells build new bone tissue.
Osteoblasts
These tiny functional units of the kidneys filter blood and process the filtrate.
Nephrons.