Simple Closed loop hydraulic system help?

I am making a simple hydraulic model of a cardiovascular system for my undergraduate final project. Right now I'm trying to learn simscape to build myself a closed loop hydraulics model for simulation. I have attached a simulink file of what i currently have. The fixed displacement pump(heart) is pumping water from the tank and supply it around the system, there is a gate valve that simulates resistance once the blood go through an organ, hydraulic pipes are used as arteries. As the project progress more features will be added that will resemble the cardiovascular further. My question is: the fixed displacement pump component in simscape is an enigma i dont know how it works. My original plan is using a hydraulic piston pump like the picture below as my heart.

How can I model this pump in simscape and making it into a closed loop, using simple components?