Biology Study Guide TopicsEndocrine System | Lymphatic System | Blood | Circulatory System | Skull Bones | Human Skull and Brain | Tissue Types | The Cell | DNA | Anatomy Models | Electron Transport Chain | History of Microbiology | Human Anatomy | Punnett Squares | What is Mitosis | What is Life | Macromolecules | Cellular Respiration | DNA Replication | Enzymes | Pathogenic Bacteria | Natural Selection | Punnett Squares | Transcription and Translation | Exam Notes | Viruses | Osmosis | Protists | Genetic Code | Mendelian Genetics | Meiosis | Sensory Processing | Amino Acids |
Online PresentationsBones of the Human Skull | Tissue Types | Selective and Differential Media
Classroom ActivitiesRecombinant DNA Cut And Tape Classroom Activity
The Lymphatic System
1) The lymphatic system consists of lymphatic vessels and organs which serve to return fluids from the body back into the blood stream.
2) Lymph is the fluid that is carried inside of the lymphatic vessels.
3) Lymphatic capillaries meet with blood capillaries in capillary beds to return fluid to the blood.
4) Lymph nodes are connected to the lympatic vessels. Lymph nodes serve mainly to filter bacteria and viruses from lymph before it returns to the blood stream.
5) Each person has about 500 - 700 lymph nodes in their body.
6) Lymph nodes contain macrophages and lymphocytes. Macrophages are white blood cells that destroy bacteria and viruses. Lymphocytes are white blood cells that secrete antibodies to target bacteria and viruses for elimination.
7) Lymph nodes are kidney shaped, about 1 inch long and have an inner part (the medulla) and an outer part (the cortex).
8) There are other organs which play a role in the lymphatic system including the spleen, thymus, tonsils and Peyer's patches.
9)The spleen filters blood, breaks down worn out red blood cells and serve as a reservoir of blood. It is found in the abdomen.
10) The thymus gland is located in the throat, just above the heart. During childhood it produces hormones that aid the development of lymphocytes of the immune system.
11) The tonsils are found around the mouth and also filter and destroy foreign agents (bacteria and viruses).
12) Peyer's patches are found in the small intestine and also function in eliminating bacteria.