BIO 11 Lecture Notes - Lecture 3: Reticular Connective Tissue, Mucous Membrane, Thymus
3 Sep 2020
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Developing veins bud off lymph sacs at 5th week. 1st to form are jugular lymph sacs. The point at which the lymphatic system is connected to the circulatory. Also from vena cava and iliac veins. These form branching system of lymphatic vessels. Connection of jugular sac w/ jugular veins become right lymphatic duct and. Lymphoid organs develop from mesodermal mesenchyme that becomes reticular thoracic (left) duct tissue. 1st lymphatic organ to develop is thymus outgrowth of the pharynx. Directs the development of the rest of the lymphatic organs. Keep things from getting in the body. 1 of the best barriers several layers of densely packed. Skin is slightly acidic which kills bacteria. All body cavities are lined with this physical barrier. Can also trap bacteria and break it down. Mast cells: loosely phagocytic bind, ingest, kill anything foreign. Natural killer cells: type of lymphocyte that is nonspecific. Assassins of all lymphocytes do not care what it is only.
