The plunger can be linearly pulled .
The plunger can be linearly pushed along the inside of the tube , allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front ( open ) end of the tube .
The plunger can be linearly pulled and pushed along the inside of the tube , allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front ( open ) end of the tube .