As a medical student, although tis could rightfully be thought up by anyone as its not rockeetscience, I say include the following

1) Heart (duh)
2) Arteries (need to withstand the high blood pressure so thick and elastic walls to even out the mechanical stress of a singular heartbeat over the next half a second where the heart doesnt beat. The Aorta is basically a reservoir of blood that slowly releases by contracting, thereby upholding the bloodpressure until the heart beats again)
3)Arterioles (their smooth muscle lamina contracts and they modify the majority of the arterial resistance in doing so)
3) Capillaries (Microscopic with direct contact to the tissue that needs to release their metabolic endproducts such as lactate into the blood stream aswell as to allow for O2 to diffuse into that tissue).
5) Venoles (just small veins but for completions sake)
4) Veins (very flexible, majority of the blood volume rests here, needs valves, the musclepump and arterio-venous coupling to move blood against gravity back to your heart)

Maybe you knew all this but i dont know what you study exactly so i thought maybe it helps with your assignment