BIO30s 4_14_lymphaticsystem


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BIO30s 4_14_lymphaticsystem

  1. 1. Entry slip: How do vaccines get inside the patient’s body? Lesson 4.14- Explain the role of the lymphatic system in protecting the human body. (pp322-324) of Biology-McGraw-Hill Ryerson) I. Terms: a.Lymph: blood plasma that has escaped outside the circulatory system’s vessels b. Interstitial fluid: fluid that surrounds every cell of our body. A.k.a “extracellular” fluid. II. Lymphatic System: a.A system of vessels and capillaries that extends throughout the human body. i. The lymphatic vessels and capillaries run beside each and every circulatory system vessel and capillary.
  2. 2. b. Instead of transporting blood, it transports LYMPH, which is very much like blood plasma. c. Due to blood pressure and the small size of the molecules that make up blood plasma, some blood plasma squeezes out of the circulatory system’s capillaries. i. If this continued, the blood in the circ system would become very viscous, or slow-moving. ii. As well, we would have severe swelling due to the escaped plasma being in our tissues instead of our blood. d.The lymph is carried back to the center of the body from the arms and legs, and rejoins the circulatory system in the big veins near the heart. III. How the lymphatic system protects: a. Fluid balance.
  3. 3. i. The lymphatic system’s function of bringing escaped plasma, or lymph, back to the circulatory system helps to prevent blood from being dehydrated. ii. As well, it is the plasma in the blood that carries dissolved nutrients. If this plasma left the circulatory system never to return, areas of the body that need certain nutrients may be damaged. iii. Our ability to move our joints would be reduced if we had severe swelling and this could be dangerous (i.e. we could trip and get injured). b. White Blood Cells. i. Lymphocytes are made in special collecting areas along our lymphatic vessels, called lymph nodes. All lymph in the lymphatic system runs through these nodes which act like filters to inspect the lymphatic fluid for foreign
  4. 4. pathogens. These are based mainly in our neck, armpits and pelvis. ii. Macrophages, similar to leukocytes, also are found in the lymph nodes and will engulf and digest bacteria. iii. When we are sick and more lymphocytes and macrophages are needed, production of these in the lymph nodes increases, and the lymph nodes actually swell up. This is why your doctor will feel your neck when you feel sick to check if your body is fighting a foreign pathogen. IV.Youtube search: a. LYMPHATIC SYSTEM-dr. Moffet b.lymphatic system - aaronnelsonn V. Homework: a. Create a concept map outlining the movement of blood plasma from the blood of the circulatory system, through the lymphatic system, back to the
  5. 5. circulatory system. Include information about lymph nodes.