A chateter is a tube mostly made of rubber and used for drawing urine from the bladder when the patient is unable to do it voluntarily. It must be sterilized bby boiling before use.
In the female, the length of the canal (urethra) from the outside opening to the inside of the bladder is only about 1,5 inches, therefore, the catheter need no be inserted for more than 2-3 inches in order to empty the bladder.
In the male, the urethra is a about 9 inches long and the catheter must be passed in to at least 10 inches. Longer and wider catheter are used for administering high enemas and for stomach washing and tube feeding.
Many woman in desperation use catheters in the uterus to bring on delayed menstruation. This is a life-endangering procedure no matter who does it, the patient herself, midwife or nurse