What is the spread of malignant cells through blood and lymph to distant sites called quizlet?

Medical Terminology for Cancer

© Copyright 1996-2013

9: The Lymphatic and Immune Systems

Contents

Functions of the lymphatic system

The key functions of the lymphatic system:

• Drains excess fluids and proteins from tissues all around the body and returns them back into the bloodstream.
• Removes waste products produced by cells.
• Fights infections.
• Absorbs fats and fat-soluble vitamins from the digestive system and transports these into the bloodstream.

Components of the lymphatic system

Immage source: Wikimedia License: CC-BY-3.0

LymphLymph is a fluid that circulates throughout the body in the lymphatic system. It forms when tissue fluids/blood plasma (mostly water, with proteins and other dissolved substances) drain into the lymphatic system. It contains a high number of lymphocytes (white cells that fight infection). Lymph that forms in the digestive system called chyle, this contains higher levels of fats, and looks milky white.Lymph vesselsWalled, valved structures that carry lymph around the bodyLymph nodesSmall bean-shaped glands that produce lymphocytes, filter harmful substances from the tissues, and contain macrophages, which are cells that digest cellular debris, pathogens and other foreign substances. Major groups of lymph nodes are located in the tonsils, adenoids, armpits, neck, groin and mediastinum.ThymusThe thymus is a specialized organ of the immune system, located between the breast bone and heart. It produces lymphocytes, is important for T cell maturation (T for thymus-derived).SpleenThe spleen is an organ in the upper left abdomen, which filters blood, disposes of worn-out red blood cells, and provides a 'reserve supply' of blood. It contains both red tissue, and white lymphatic tissue. Different parts of the the spleen specialize in different kinds of immune cells.

The major (encapsulated) lymphatic organs are the lymph nodes, thymus and spleen. In addition the lymphoid tissues include:

Major clusters of lymphatic nodules include:

• Tonsils: these are clusters of lymphatic tissue under the mucous membrane lining of the nose, mouth, and throat. Lymphocytes and macrophages in the tonsils provide protection against foreign substances and pathogens that enter the body through the nose or mouth.
• Adenoids: A cluster of lymphatic tissue that hangs from the upper part of the back of the nasal cavity. Adenoids get bigger after birth but usually stop growing by the age of 7. Like the Tonsils, they can be removed without significantly increased risk of infections.
• Peyer's patches: these are clusters of lymphatic nodules in the mucosa that lines the ileum of the small intestine. They play an important role in defending against the large number of pathogens that enter the gastrointestinal system.

Circulation of tissue fluids

Fluid in the spaces between tissues is called interstitial fluid, or 'tissue fluid'. This provides the cells of the body with nutrients (via the blood supply) and a means of waste removal. Lymph is formed when the interstitial fluid is collected through tiny lymph capillaries (see diagram), which are located throughout the body. It is then transported through lymph vessels to lymph nodes, which clean and filter it. Lymph then flows on to the lymphatic ducts, before emptying into the right or the left subclavian vein, where it mixes back with blood.

Blood is enriched with oxygen (by the respiratory system) and nutrients (by the digestive system), which are circulated all around the body (by the cardiovascular system). Some fluid (blood plasma) leaks out into the tissues via tiny capillaries, contributing to interstitial fluid, which eventually drains back into the lymphatic system.

The Immune System

The immune system includes a variety of defenses against viruses, bacteria, fungal infections, and parasites (such as thread worms). The lympatic system is part of the broader Immune System.

• Physical and chemical barriers to pathogens.
• Producing cytokines and other chemical factors to recruit immune cells to sites of infection.
• Activates the complement cascade to identify bacteria, activate cells and to promote clearance of dead cells or antibody complexes.
• Identifies and removes foreign substances present in organs, tissues, the blood and lymph, by specialised white blood cells.
• Activation of the adaptive immune system, through a process known as antigen presentation.

• Recognition of specific "non-self" antigens, during the process of antigen presentation.
• The generation of responses tailored to destroy specific pathogens or pathogen-infected cells.
• Development of immunological memory, in which each pathogen is "remembered" by signature antibodies or T cell receptors. These memory cells can be called upon to quickly eliminate a pathogen should subsequent infections occur.

There are many different cell types and sub-types involved in the immune system. Some of the main types include:

• Lymphocytes: are white cells which circulate between blood and lymph. They play an important role in fighting infection. There are many kinds of lymphocytes; the main types are T cells, B cells and natural killer cells. Lymphocytes initially develop in the bone marrow. Some migrate to the thymus, where they mature into T cells ; others mature in the bone marrow as B cells.
• Neutrophils: are the most abundant type of white blood cells and are an important part of the innate immune system. Neutrophils are a type of phagocyte (cells which engulf and then digest, cellular debris and pathogens). They are normally found in the blood stream, but are quickly recruited to the site of injury or infection following chemical signals such as Interleukin-8.
• Macrophages: are another type of phagocyte and have a role in both the innate and adaptive immune systems. They attack foreign substances, infectious microbes and cancer cells. Macrophages also stimulate lymphocytes and other immune cells to respond to pathogens.
• Dendritic cells: are antigen-presenting cells which act as messengers between the innate and adaptive immune systems. They are usually located in tissues in contact with the external environment such as the skin, linings of the nose, lungs, stomach and intestines. In response to pathogens they migrate to the lymph nodes where they interact with T cells and B cells to initiate the adaptive immune response.

Cancer Focus

Roots, suffixes, and prefixes

Most medical terms are comprised of a root word plus a suffix (word ending) and/or a prefix (beginning of the word). Here are some examples related to the Lymphatic and Immune systems. For more details see Chapter 4: Understanding the Components of Medical Terminology

Related Abbreviations and Acronyms

Further Resources (9 links)

 Immune System

National Cancer Institute
Detailed presentation and notes.


 Introduction to the Lymphatic System

SEER, National Cancer Institute
Part of a SEER training module for cancer registry staff.


 Lymphatic System - Self Test questions

WebAnatomy, University of Minnesota
Test your anatomy knowledge with these interactive questions. Includes different question types and answers.


 Mechanism of lymph node metastasis in prostate cancer

Future Oncol. 2010 May;6(5):823-36
Datta K, Muders M, Zhang H, Tindall DJ. Mechanism of lymph node metastasis in prostate cancer. Future Oncol. 2010 May; 6(5): 823-836. (full article available free on PubMed Central)


 Sentinel Lymph Node Biopsy

National Cancer Institute
Factsheet in the form of questions and answers, with references.


 The components of the immune system

National Library of Medicine
A section, with diagrams from: Janeway CA Jr, Travers P, Walport M, et al. Immunobiology: The Immune System in Health and Disease. 5th edition. New York: Garland Science; 2001.


  The Immune System


Paul Andersen
Paul Andersen explains how your body protects itself from invading viruses and bacteria. He starts by describing the nonspecific immune responses of skin and inflammation. He then explains how we use antibodies to disrupt the function of antigens and mark them for destruction. He then explains both the homoral and cell-mediated immune response highlighting the importance of B and T lymphocytes. He finally describes the process of long term immunity.


 The Lymphatic System

Cancer Research UK
Short overview, with diagrams.


  Your Immune System 101: Introduction to Clinical Immunology


UCSF
Dr. Katherine Gundling, Professor, Division of Allergy and Immunology at UCSF presents an overview of the immune system, how it functions and what can go wrong.

This guide by Simon Cotterill

First created 4th March 1996
Last modified: 1st February 2014

What is the spread of malignant cells through the blood to distant sites called?

What is meant by metastatic?

What is the difference between metastasis and metastases?

What is the difference between metastatic and malignant?