Needles are used in various medical and other applications, but their basic function is to create a pathway for fluids or substances to enter or leave the body or a particular area. They typically consist of a hollow shaft with a sharp tip, attached to a syringe or other device. Here's a breakdown of how they work:
- Fluid Delivery: Injections involve drawing up fluid into the syringe and then inserting the needle through the skin into the desired location. By pushing the plunger of the syringe, the fluid is forced through the needle's lumen (hollow space) into the body. This method is used for administering medicine, vaccines, blood transfusions, and other medical treatments.
- Fluid Extraction: Some needles are designed to extract fluids from the body. For example, a needle may be inserted into a vein to draw blood for testing or into a cyst to remove fluid.
- Biopsy and other procedures: Needles are also used for collecting tissue samples for analysis (biopsy) or to perform other medical procedures such as draining fluids or injecting medication into specific locations.
Here are some practical examples:
- Hypodermic needles: Commonly used for administering medications and vaccines.
- Intravenous needles (IVs): Used for injecting fluids directly into veins for hydration or delivering medication.
- Acupuncture needles: Used in traditional Chinese medicine to stimulate specific points on the body.
- Tattoo needles: Used to deposit ink into the skin, creating a permanent image.
Key takeaway: Needles function as conduits, enabling the transfer of fluids or substances into or out of a body or specific area. The method of use varies depending on the type of needle and its purpose.
