Term
| What is the lymphatic system? |
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Definition
| A system of lymph nodes, lymph vessels, and other lymphoid organs and tissues. |
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Term
| What systems depend on the lymphatic system? |
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Definition
| The cardiovascular and immune systems |
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Term
| What are the two semi-independent components that comprise the lymphatic system? |
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Definition
A network of lymphatic vessels and
various lymphoid tissues and organs scattered throughout the body. |
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Term
| What is the function of the lymphatic vessels? |
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Definition
| Transport back blood fluids that have exited the vascular system and are interstitial fluids |
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Term
| What is the function of the Lymphoid Tissues? |
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Definition
Contain phagocytic cells and lymphocytes;
Play vital roles in the body’s defense and resistance to disease. |
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Term
| What are lymph vessels (lymphatics)? |
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Definition
| Fluid that is forced into interstitial spaces is returned into the vascular system via lymph vessels |
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Term
| Why are lymph vessels important? |
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Definition
| Fluid must be returned into vascular system in order to have sufficient blood volume to serve the body; can return 3 liters a day |
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Term
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Definition
- Fluid that accumulates in the tissues
- Appears as swelling
- Excessively, it impairs the ability of tissue cells to exchange gases, nutrients, wastes, etc. with the blood |
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Term
| What do lymphatic vessels do? |
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Definition
* They form an elaborate drainage system that picks up excessive tissue fluid
* They form a one-way system that moves lymph towards the heart. |
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Term
| What are lymphatic capillaries? |
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Definition
| small lymph vessels that weave between the blood capillaries and loose connective tissues and absorb leaked fluid. |
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Term
| Describe lymph vessels / how they work. |
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Definition
- Very permeable and not open ended
- Loosely overlapping walls forming flap-like one-way mini-valves
- Valves open with increased pressure from interstitial fluid--fluid into lymph vessels
- Fluid cannot travel in the opposite direction. |
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Term
| How do lymph vessels help protect against disease? |
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Definition
Bacteria, viruses, and cell debris not able to enter capillaries are able to enter lymph vessels.
They are trapped in the lymph nodes as the lymph fluid is filtered through the nodes. |
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Term
Lymph is eventually returned into the venous system through two large ducts called ____ and _____.
Both ducts empty into _____ on the respective side |
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Definition
- The Right Lymphatic Duct
- The Thoracic Duct
- The Subclavian Vein |
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Term
| What does the Right Lymphatic Duct do? |
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Definition
| Drains the right upper extremity and right side of the head and trunk |
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Term
| What does the Thoracic Duct do? |
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Definition
| Drains lymph from the remainder of the body |
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Term
Lymph vessels are ____. Larger vessels have ____. They use a _____ with _____
Lymph is returned to circulation by _____ that assist in fluid flow and _____ during _____.
Larger vessels have _____ to contract |
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Definition
- thin-walled
- valves
- pumpless system
- low pressure
- skeletal muscle contractions
- thoracic pressure changes
- breathing
- smooth muscle |
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Term
| What are the lymph nodes? What do they do and what do they produce? |
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Definition
Lymphoid tissue associated with the immune system that helps protect the body by removing foreign material (bacteria, etc) from the lymph fluid.
They also produce lymphocytes |
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Term
| Where are large clusters of lymph nodes found? |
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Definition
| The inguinal (groin), axillary(armpit), and cervical regions. |
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Term
| What do lymph nodes contain? |
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Definition
Macrophages – engulf foreign substances
Lymphocytes – WBCs that respond to foreign substances. |
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Term
| When are lymph nodes swollen? |
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Definition
During active infection
Swelling is a result of trapped bacteria, etc. |
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Term
| What is the fibrous capsule? |
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Definition
| The fibrous capsule surrounds each node |
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Term
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Definition
| These extend inward and divide each node into compartments |
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Term
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Definition
| This is the outer part of the node compartment. |
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Term
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Definition
| These are found inside each lymph node compartment. They contain collections of lymphocytes. |
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Term
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Definition
| This is the central portion of the entire lymph node. It contains phagocytic macrophages. |
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Term
Fluid enters the convex side of the lymph nodes through the _______.
It continues to flow through the _____.
Then it exits from the node at the indented region or _____ via the ____ |
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Definition
- Afferent lymphatic vessels
- Sinuses
- Hilum
- Efferent lymphatic vessels |
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Term
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Definition
Very slow through the node
Allows time for the lymphocytes and macrophages to activate.
Lymph flows through several nodes in order to cleanse fluid. |
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Term
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Definition
Blood rich organ
Filters blood
Destroys worn-out red blood cells and returns them to the liver
Stores platelets
Hematopoietic function in fetus
Lymphocytes are produced (adults) and found in spleen to assist with the immune system |
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Term
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Definition
Establishes immunity during youth
Produces hormone, thymosin, that program lymphocytes to carry out protective roles
(peak of function during adolescence). |
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Term
| What is the autoimmune disease caused by the thymus? |
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Definition
Myasthenia gravis (MG).
Often, a thymectomy helps to control the severity of MG symptoms |
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Term
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Definition
Small masses of lymphoid tissue in the pharynx
Trap and remove bacteria entering the throat |
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Term
| What are Peyer's Patches? |
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Definition
- Tonsil-like structures in the wall of the small intestine.
- Present in large numbers
- Contain macrophages that destroy bacteria and prevent from penetrating the intestine wall. |
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Term
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Definition
Mucosa Associate Lymphatic Tissue (MALT)
Protects the upper respiratory and digestive tracts from never ending attacks of foreign matter entering those cavities.
Tonsils and Peyer's Patches are made up of these. |
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