2. To draw out or to remove as if by percolation or seepage; to dissolve, to remove, or to wash out: Francisca poured water through the ashes from the fireplace to leach the lye in the ash so she could make soap.
2. Someone who uses other people for personal gain or anyone who tries to get what he or she can swindle from others: Celebrities often have at least one leech who tries to leech them for money or other material rewards.
One species of the this blood-sucking worm has been used in medical treatments for many years to leech patients or to eat away putrid flesh from a wound.
When using a leech on the patient, the doctor was heard to comment that he wished it were as easy to leach toxins from the soil as it is to leech toxins from an ill person using a leech or two.
Is it proper to say that a leech can leach blood from an animal?
As a matter of fact, a leech is known to leech blood and dead flesh from bodies while leaching is quite a different process.
In chemical engineering, to leach is the procedure used for separating a soluble substance from a solid by washing or by the percolation of water or other liquid through the substance, as when making coffee.
In geochemistry, to leach is specifically the natural or artificial removal of soluble substances from rock, ore, or layers of soil by the action of percolating substances; such as, water.
A medicinal leech, known as Hirudo medicinalis was utilized in the distant past and is being used again in the modern application of leech blood from patients for specialized procedures.
There is also a tool being used by medical doctors called an artificial leech which consists of a cup and suction pump, or syringe, for drawing blood.
For much more information about leeches and leeching, go to this Medicine, Leeching for Health page.
2. One species has been used in medical treatments to bleed patients or to eat away putrid flesh from a wound.
3. Any of numerous carnivorous or bloodsucking annelid worms that constitute the class Hirudinea, that typically have a flattened segmented lance-shaped body with well-marked external annulations (ringlike structures, segments, or parts), a sucker at each end, a mouth within the anterior sucker, and a large stomach with pouches of large capacity at the sides.
Such pouches are hermaphroditic (having both male female reproductive organs); usually, with direct development, and which occur chiefly in fresh water, although a few are marine and some tropical forms are terrestrial.
2. To bleed patients for medical treatment by the use of leeches.
3. A nursing intervention from the Nursing Interventions Classification (NIC) defined as application of medicinal leeches to help drain replanted or transplanted tissue engorged with venous blood.
Thousands of patients currently owe the successful reattachment of body parts to miraculous technological advances in plastic and reconstructive surgery; however, at least some of these operations might have failed if leeches had not been reintroduced into the operating room. The appendages reattached include fingers, hands, toes, legs, ears, noses and scalps.
Leeches were used as a method of bloodletting, a practice common up to the middle of the 19th century.
In modern times, leeches have been used to evacuate periorbital hemorrhage (black eye) and to remove congested venous blood from the suture lines of re-implanted fingers.
Sometimes, a patient's veins are too weak to carry blood and it builds up, causing venous congestion and since leeches are a source of hirudin, an anticoagulating principle secreted by their buccal glands and leech saliva contains several active substances including inhibitors of platelet aggregation, they are used to decrease such venous congestion.
The leech's saliva contains substances that anesthetize the wound area, dilate the blood vessels to increase blood flow, and prevent the blood from clotting and so attaching leeches to the body draws the blood away gradually and painlessly.
Leeches are particularly useful in plastic surgery; such as, breast reconstruction and where a part of the body has become severed and had to be sewn back on.