Parts of Syringe and Needle

What is Syringe?

The syringe is a simple reciprocating pump where the plunger acts as a piston that slides into the barrel to pull or push medicine or blood from or into the body.

Parts of Syringe

  • Plunger
  • Thumb Rest
  • Barrel
  • Luer Lock

Parts of Needle

  • Needle Hub
  • Needle Shaft
  • Bevel
  • Protective Cover
Parts of Syringe and Needle

Parts of Syringe and their Functions


In the Syringe, a plunger is a piston that is pressed into the barrel to force liquid through the needle. With the help of a plunger, we can pull and push liquid medicine into the barrel. 

Thumb Rest

It is the end portion of the plunger. It is flat in shape. We can rest our thumb on it while expels the liquid. On the other end of the plunger, a rubber cap is there to avoid leakage and air-tight sealing. 

Generally, the material of the plunger is plastic or colored glass.


A barrel is a cylindrical part of the syringe in which liquid medicine or blood can be pulled or pushed. 

The barrel has a calibration scale to measure the quantity of medicine or blood to give or remove from the body of the patient.

Luer Lock

This Luer lock is the end connection of the syringe. It has a screw structure that allows the needle to get fit with the syringe. 

There are three Luer lock connections are there. Luer Lock Tip, Luer Slip Centric Tip, Luer Slip Eccentric Tip.

Parts of Needle and their Functions

Needle Hub

It is an adapter that holds the needle and the other ends get to connect with a syringe. It locks the needle with the syringe while pulling and pushing the liquid medicine into the body.

Needle Shaft

A needle shaft is a steel needle that is fixed in the needle hub. It is hollow from the inside to pass liquid medicine from it.

Needle Bevel

A needle bevel is a cut at the end of the needle. It has a sharp edge that helps to insert the needle into the body of any animal.

Needle Protective Cover

It is a protective cover to protect the needle from any dust particles that enter it. It is a simple cap that can be covered or removed.

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