The spleen. It acts as a filter for blood, but also, as you said, is a reservoir for oxygen rich blood.
Liver
Your Heart is an organ that pumps blood through your body.
The organ responsible for breathing is your lungs.
J-shaped organ is a stomach
Contractile Vacuole is the organelle responsible for excreting and collecting cellular waste.
spleen
your intestines
thymus
The chloroplast
The Heart
pancreas
kidneys
The kidney is the organ that manages the water content of the blood. People typically have two.
A blood vessel is a tube shaped organ that carries blood. It carries the blood through the tissues and organs of the human body.
The skeletal system is what is responsible for calcium and phosphorous storage and hematopoiesis. Hematopoiesis is the production of blood cells.
Liver
Lymph nodes