Exercise 35A: The Lymphatic System and Immune System
Match the terms with the correct letters in the diagram.
A. TONSILS
B. CERVICAL LYMPH NODES
C. THORACIC DUCT
D. THYMUS
E. SPLEEN
F. PEYER'S PATCHES (IN INTESTINE)
G. INGUINAL LYMPH NODES
H. LYMPHATIC VESSELS
I. BONE MARROW
J. CISTERNA CHYLI
K. AXILLARY LYMPH NODES
L. RIGHT LYMPHATIC DUCT
Explain why the lymphatic system is a one-way system, whereas the blood vascular system is a two-way system.
Blood vessels form a complete circuit from and to the heart. The lymphatic system lacks arteries and begins with blind-ended lymph capillaries. Thus, it is a "return" system only.
How do lymphatic vessels resemble veins?
The lymphatic collecting vessels have three tunics and are equipped with valves.
How do lymphatic capillaries differ from blood capillaries?
Blood capillaries carry blood from small arterioles to small venules.
Lymphatic capillaries carry lymphatic fluid from tissue to lymphatic venules.
In structure, lymph capillaries are slightly bigger in diameter but have thinner walls than blood capillaries
What is the function of the lymphatic vessels?
Lymphatic vessels carry lymph from peripheral tissues to the venous system. The lymphatic system transports lymphocytes, is involved in the removal of foreign matter & cell debris by phagocytes & is part of the body's immune system. It also transports fats from the small intestine to the blood.
What is lymph?
Lymph is a clear to yellowish watery fluid which is found throughout the body. It circulates through body tissues picking up fats, bacteria, and other unwanted materials, filtering these substances out through the lymphatic system; a thin coagulable fluid (similar to plasma but) containing white blood cells (lymphocytes) and chyle
What factors are involved in the flow of lymphatic fluid?
The milking action of the skeletal muscles and on pressure changes within the thorax that occur during breathing.
What name is given to the terminal duct draining most of the body?
thoracic duct
What is cisterna chyli?
Enlarged terminus of the thoracic duct that receives lymph from the digestive viscera.
How does the composition of lymph in the cisterna chyli differ from that in the general lymphatic stream?
They are the same except that the lymph in the cisterna chyli is very fat-rich
Which portion of the body is drained by the right lymphatic duct?
right upper extremity, head and thorax
Note three areas where lymph nodes are densely clustered: _____________, ______________, and ______________.
inguinal, axillary, and cervical regions of the body.
What are the two major functions of the lymph nodes? _________________________________ and _______________________________.
filtering and protection
The radical mastectomy is an operation in which a cancerous breast, surrounding tissues, and the underlying muscles of the anterior thoracic wall, plus the axillary lymph nodes, are removed. After such an operation, the arm usually swells, or becomes edematous, and is very uncomfortable -- sometimes for months. Why?
The lymphatic fluid is not being drained from the area due to a disruption of lymphatic vessels and nodes.
What is the function of B cells in the immune response?
B cells differentiate into plasma cells that secrete antibodies. Antibodies are proteins that bind to specific antigens and mark them for destruction. They provide humoral immunity.
What is the role of T cells?
directly attack virus-infected tissue cells, some help activate the B cells and cytotoxic T cells, and others can inhibit the immune response. They provide cellular immunity.
Define the following term related to the operation of the immune system.
Immunological memory
when the immunity system has/stores a memory from a previously encountered foreign antibody.
Define the following term related to the operation of the immune system.
specificity
the quality of having a certain action, reacting only with certain substances, as antibodies with certain antigens (antigen specificity). Like B cells with antibodies.
Define the following term related to the operation of the immune system.
recognition of self from nonself
Self recognition immunity is when something goes into the body and it has been there before. The body automatically puts a marker specific to only that substance on it so that anytime it is in contact with the body it will recognize it. Non-recognized immunity is when a foreign substance enters the body. In this case the body has defense teams designed to attack and rid the body of the foreign substance.
Define the following term related to the operation of the immune system.
autoimmune disease
When the immune system attacks the body (doesn't recognize a body tissue, identifies it as foreign)
What structural characteristic ensures a slow flow of lymph through a lymph node? Why is this desirable?
each lymph node has fewer efferent than afferent vessels, so the lymph flow stagnates somewhat within the node; this is desirable because it allows time for the generation of an immune response and for the macrophages to remove debris from the lymph before it reenters the blood vascular system
What similarities in structure and function are found in the lymph nodes, spleen, and tonsils?
Structurally:
o They all have a capsule
o They are rounded organs with an internal parenchyma of lymphoid cells
o They are placed strategically about the body in order to maximally filter air/blood/lymph - see functional similarities
Functionally:
o All of these organs are involved in the immune system
o Their role is to filter air/blood/lymph and expose the white blood cells within them to foreign material and thus activate the body's immune system
Distinguish between antigen and antibody.
Antigens are substances that provoke an immune response (they're the ultimate target for the immune system). Antibodies are simply proteins that are secreted as a result of the antigen provoked immune response. In short, antigens cause the disease and antibodies cure it.
Describe the structure of the immunoglobulin monomer.
Each monomer is composed of four protein chains(two heavy chains and two light chains) connected by disulfide bonds. both the heavy and light chains have regions of constnt amino acid sequence (c regions) and regions of variable amino acid sequence (v regions). The variable regions differ in each type of antibody and construct the antigen-binding sites. Each immunoglobulin monomer has two such antigen-specific sites.
Are the genes coding for one antibody entirely different from those coding for a different antibody? Explain your answer.
no, not entirely. Each antibody (Immunoglobulin, "Ig") has both 2 constant regions referred to as "heavy hains" and 2 variable regions referred to as "light chains". The structure of the heavy chains remain the same between the different antibody structures. However, the light chains differ in structure enabling them to respond differently to different specific antigens introduced to the cellular membrane.
In the Ouchterlony test, what happened when the antibody to horse serum albumin mixed with horse serum anbumin?
You will get an antibody-antigen reaction. If on a solid phase, like an Ouchterlony agarose gel you will see a white precipitin line. If in a liquid, like in a test tube, you will see a white precipitate.
If the unknown antigen contained bovine and swine serum albumin, what would you expect to happen in the Ouchterlony test, and why?
percipitin line forms