AP BIOLOGY

Detailed explanation-1: -The spleen acts as a filter. It weeds out old and damaged cells and helps control the amount of blood and blood cells that circulate in the body. The spleen also helps get rid of germs. It contains white blood cells called lymphocytes and macrophages.

Detailed explanation-2: -Lymph nodes are small clumps of tissue along the network of lymph vessels that clean lymph as it moves through them. They filter out viruses, bacteria, and fungi that can cause illnesses. Most lymph nodes are in clusters in the neck, armpit, and groin area.

Detailed explanation-3: -Thymus. The thymus is inside the ribcage, just behind the breastbone. It filters and monitors our blood content. It produces cells called T-lymphocytes which circulate around the body.

Detailed explanation-4: -Lymph nodes are small, bean-shaped masses of lymphatic tissue along lymph vessels. They store lymphocytes and filter waste, bacteria and damaged cells (including cancer cells) from lymph. The lymphocytes inside the lymph nodes also attack bacteria and viruses that they find in the lymph.

Detailed explanation-5: -Human lymphoid organs. Lymphocytes develop in the thymus and bone marrow (yellow), which are therefore called central (or primary) lymphoid organs.