An average human body has around four million sweat glands which are responsible for regulating body temperature and helping eliminate some toxins and metabolic waste. The number of sweat glands varies between sites on the body with an abundance of such glands on the palms and soles.
Homeostatic mechanisms respond to an increase in body temperature by opening up sweat glands onto the pores of the skin in order to secrete water and other substances. As the water evaporates it cools down the skin and the pores then close back up again in an ongoing cycle of temperature regulation.
The Lymphatic System
Lymph vessels do not excrete substances out onto the skin but, instead, drain excess fluid between cells and deal with threats to the body, such as bacteria or viruses.
Lymph fluid is not pumped around the body through the vast network of lymph vessels and nodes. It is the regular contraction and relaxation of muscles during daily activities that squeezes and pushes the fluid around the system. The lymphatic system also transports fats and fat-soluble vitamins (A, D, E, K and B12) around the body after absorption from the gut.
What is Lymph and Why do Lymph Nodes Swell?
Lymph fluid is a mix of white blood cells, fats, water and proteins. Dehydration, excess dietary fat and inadequate protein can all contribute to a sluggish lymphatic drainage system, resulting in poorer immune system function, swollen lymph nodes and skin issues from toxic build-up.
When the body is infected by bacteria or another organism the invader is trapped in the lymph nodes, which become enlarged, in order to concentrate the attack from the immune system.
As the infection is killed by immune system cells the dead organisms are flushed through the lymphatic system to be eliminated. Lymph nodes remain swollen for a short period after infection as the concentration of white blood cells and other immune system components gradually reduces.