Question

Review &Practice Sheet Exercise 38 C. Short-Answer Questions 1. Describe the organization of a lymph node. Discuss the major functions of the lymphatic system. 2. Explain how lymph is returned to the blood. 3. Describe the anatomy of the spleen. 4. D. Application and Analysis 1. How are blood plasma, extracellular fluid, and lymph interrelated?

Answer 1

C.1.A lymph node is formed by the stromal cells which divide the node into components and guide migrating lymphocytes and accessory cells.It is surrounded by fibrous capsule which extends inside a lymph node to form trabeculae.It comparises a superficial cortex,a deep cortex and a medulla.Components of lymph nodes are vessels(lymphatics),fluid(lymph),lymphocytes and lymphoid tissue and organ.

2.The major function of lymphatic system:-

a) Responsible for removal of interstitial fluid from tissue.

b) Absorption of fatty acids and helps in transportation of fat,chyle to circulatory system.

c) Transportation of white bloods cells to and from lymph nodes into bones.

d) Production of immune cells such as monocytes,lymphocytes and plasma cells.

3)Right lymph duct drains the upper right portion of the body returning lymph to the bloodstream through right subclavian vein.The thoracic duct drain the rest of the body into the left subclavian vein.

4) Anatomy of Spleen:-

Spleen is a wedge shaped organ lying in left hypochondrium and partly in epigastrium.It is wedged in between fundus of stomach diaphragm.

It is soft ,highly vascular and dark purple in colour.The size and weight of spleen is 1 inch and 7 ounces in weight and is related to 9th to 11th ribs.It lies obliquely along the long axis of 10th rib.Thus it is directed downwards,forwards and laterally making an angel of about 45 degrees with horizontal.It has two ends,three borders and two surfaces.

It is supplied by splenic artery and venous drainage by splenic vein.

D.1) Lymph a fluid similar in composition to blood plasma .It is derived from blood plasma as fluid pass through capillary walls at the arterial end.As interstitial fluid begins to accumulate ,it is picked up and removed by tiny lymphatic vessels and returned to the blood.

The fluid which is between the cells in all body tissue is called interstitial fluid.

Blood plasm is a yellowish liquid component of blood which holds the blood cells in whole blood in suspension.