By Anne Marie Helmenstine, Ph.D. Lipids are a diverse group of fat-soluble biological molecules. Here is a look at different types of lipids and where they are found.1  Triacylglycerols or Triglycerides. 2  The largest class of lipids goes by different names: triacylglycerols, triglycerides, glycerolipids, or fats.y Anne Marie Helmenstine, Ph.D. Lipids are a diverse group of fat-soluble biological molecules. Here is a look at different types of lipids and where they are found.
Lymph nodes become swollen in response to illness, infection, or stress. Swollen lymph nodes are one sign that your lymphatic system is working to rid your body of the responsible agents. Swollen lymph glands in the head and neck are normally caused by illnesses such as: 1  ear infection.
Lymph nodes make immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells. When bacteria are recognized in the lymph fluid, the lymph nodes make more infection-fighting white blood cells, which cause the nodes to swell. The swollen nodes are sometimes felt in the neck, under the arms, and groin.