A stimulating needle and catheter system, including components, is provided such that the position of the stimulating needle or the stimulating catheter may be identified after insertion into the body of a patient by electrically stimulating and thus locating a specific nerve. Use of the needle and catheter system is eased by providing the system to the medical practitioner in a unitary structure. That is, the needle and catheter are connected by a catheter lock. The catheter lock is attached to the hub of the needle and can be actuated to either firmly grip the catheter or allow the catheter to move axially with respect to the lock and needle assembly. Thus, supplying the catheter to the practitioner already locked into the catheter lock allows the practitioner to insert the needle into the patient and, when ready, release the catheter for disposal through the needle into the patient. This and other disclosed features allow the medical practitioner to focus attention on the medical procedure.