Chapter 6 - Med Term

the fluid that removes cellular waste products, pathogens, and dead blood cells from the tissues

lymph

the capillaries, vessels, and ducts that return lymph from the tissues to the venous bloodstream

lymphatic vessels and ducts

lymph/o

lymph

lymphangi/o

lymphatic vessels and ducts

bean shaped structures of the lymphatic system where pathogens and other harmful substances are filtered from the lymph by specialized cells of the immune system

lymph nodes

lymphaden/o

lymph nodes

lymphoid structures of the lymphatic system that protect the entry to the respiratory system

tonsils and adenoids

tonsill/o

adenoid/o

tonsils and adenoids

a sac-like mass of lymphoid tissue with protective roles in both the immune and lymphatic systems

spleen

splen/o

spleen

produces lymphocytes, which are specialized leukocytes

bone marrow

myel/o

bone marrow

specialized leukocytes that play important roles in immune reactions

lymphocytes

lymphocyt/o

lymphocytes

a gland located in the upper chest with specialized roles in both the lymphatic and immune systems

thymus

thym/o

thymus

1. absorb fats and fat-soluble vitamins through the lacteals of the small intestine

2. remove waste products from the tissues and cooperate with the immune system in destroying invading pathogens

3. return filtered lymph to the veins at the base of the neck

lymphatic system

small fingerlike projections

villi

are specialized structures of the lymphatic system that absorb those fats that cannot be transported by the bloodstream

• these dietary fats are transformed in the cells of the lacteals

• the lymphatic vessels then return them to the venous circulation so they can be used throughout the body as nutrients

lacteals

absorb the nutrients, fats, and fat-soluble vitamins from the digested food directly into the bloodstream for use throughout the body

blood vessels

is plasma from arterial blood the flows out of the arterioles and into the capillaries, and then flows into the spaces between the cells of the tissues

• this fluid delivers nutrients, oxygen, and hormones to the cells

• when it leaves the cells, it brigns with it waste products and protein molecules that were created within the cells - about 90% of this fluid returns to the bloodstream

interstitial fluid (aka intercellular or tissue fluid)

is made up of the remaining 10% of the returning interstitial fluid - it is a clear, watery fluid containing electrolytes and proteins, and it plays essential roles in the lymphatic system as it works in close cooperation with the immune system

• collects the protein molecules created within the cells as it leaves - also removes dead cells, debris, and pathogens (including cancer cells) from the intercellular spaces

• enters very small capillaries within the tissues and then flows into progressively larger vessles and ducts as it travels in a one-way trip upward toward the neck

• at this stage, it begins to play an active role in cooperation with the immune system to protect the body against invading microorganisms and diseases

lymph

______________ and blood circulatory system work closely together, and because of these similarities the lymphatic circulatory system is often referred to as the secondary circulatory system

• however, it is also very important to understand the differences in these two systems

lymphatic circulatory system

flows in only one direction - from its point of origin, it can move only upward until it returns to the circulatory system at the base of the neck

• once it enters a lymphatic capillary, it must continue this upward flow

lymph

are microscopic, blind-ended (sealed on one end) tubes located near the surface of the body with capillary walls that are only one cell in thickness

• these cells separate briefly to allow the lymph to enter the capillary

• then the action of the cells as they close forces the lymph to flow upward and forward

lymphatic capillaries

lymph flows from the lymphatic capillaries into the progressively larger _______, which are located deeper within the tissues

• like veins, they have valves to prevent the backward flow of lymph

lymphatic vessels

collects lymph from the right side of the head and neck, the upper right quadrant of the body, and the right arm - the lymphatic duct empties into the right subclavian vein

• the subclavian vein is the proximal part of the main vein of the arm

right lymphatic duct

is the largest lymphatic vessel in the body, collects lymph from the left side of the head and neck, the upper left quadrant of the trunk, the left arm, the entire lower portion of the trunk, and both legs

• it empties into the left subclavian vein

thoracic duct

each small, bean-shaped ______ contains specialized lymphocytes that are capable of destroying pathogens

• unfiltered lymph flows into the nodes, and here the lymphocytes destroy harmful substances such as bacteria, virues, and malignant cells

• additional structures within the node filter the lymph to remove other impurities - after these processes are complete, the lymph leaves the node and continues its journey to become part of the venous circulation again

lymph node

are located along the sides of the neck

cervical lymph nodes

are located under the arms in the area known as the armpits

axillary lymph nodes

are located in the inguinal area of the lower abdomen

inguinal lymph nodes

are leukocytes that are formed in bone marrow as stem cells

• work together with the body’s organs to defend the body against antigens

lymphocytes

is any substance that the body regards as being foreign - this includes viruses, bacteria, toxins, and transplanted tissues

antigen

process of becoming mature

maturation

means to be modified to perform a specific function

differentiation

play an important role in the killing of cancer cells and cells infected by viruses

natural killer cells

are specialized lymphocytes that produce antibodies - each lymphocyte makes a specific antibody that is capable of destroying a specific antigen

• are most effective against viruses and bacteria that are circulating in the blood - when it is confronted with the antigen that it is coded to destroy, then it is transformed into a plasma cell

b cells (aka b lymphocytes)

develop from b cells and secrete a large volume of antibodies coded to destroy specific antigens

plasma cells

get the t in their name from their origin in the thymus - these lymphocytes play a central role in cell-mediated immunity

t cells (aka t lymphocytes)

are a group of proteins such as interferons and interleukins released primarily by the t cells - these cells act as intracellular signals to begin the immune response

cytokines

are produced in response to the presence of antigens, particularly viruses or tumor cells

• activate the immune system, fight viruses by slowing or stopping their multiplication, and signal other cells to increase their defenses

interferons

play multiple roles in the immune system, including directing b and t cells to divide and proliferate

interleukins

are three masses of lymphoid tissue that form a protective ring around the back of the nose and upper throat

• play an important role in the immune system by preventing pathogens from entering the respiratory system when breathing through the nose and mouth

tonsils

are located in the nasopharynx, which is the upper part of the pharynx

adenoids (aka nasopharyngeal tonsils)

are located on the left and right sides of the throat in the area that is visible at the back of the mouth

palatine tonsils

are located at the base of the tongue; however, they are not readily visible

lingual tonsils

is a mass of lymphoid tissue located above the heart, reaches its greatest size at puberty and becomes smaller with age

• secretes a hormone that stimulates the maturation of lymphoctyes into t cells

• these t cells, which are essential to the immune system, leave through the bloodstream and the lymphatic system

thymus

hangs from the lower portion of the cecum, which is the first section of the large intestine - although its purpose was unknown for many years, recent research indicates that the appendix may play an important role in the immune system

vermiform appendix

is a sac-like mass of lymphoid tissue located on the left upper quadrant of the abdomen, just inferior to the diaphragm and posterior to the stomach

• filters microorganisms and other foreign material from the blood

• forms lymphocytes and monocytes, which are specialized leukocytes with important roles in the immune system

• has the hemolytic function of destroying worn-out erythrocytes and releasing their hemoglobin for reuse

• also stores extra erythrocytes and maintains the appropriate balance between these cells and the plasma of the blood

spleen

primary function is to maintain good health and to protect the body from harmful substances

immune system

disease-producing microorganisms

pathogens

substances that produce allergic reactions

allergens

poisonous or harmful substances

toxins

are potentially life-threatening cancer cells

malignant cells

• first attempts to prevent the entry of these harmful substances into the body - if harmful substances do gain entry into the body, it immediately begins working to destroy them

• uses a complex system of chemical signaling between specialized cells to identify, attack, and remember antigens

• this is accomplished by coordinating a highly specific response based on the type of antigen and differentiating it from the body’s own tissues to avoid attacking itself

• after encountering an antigen once, this system’s memory of the invader enables the body to mount a more efficient future defense against that antigen

immune system

• intact skin

• respiratory system traps breathed-in foreign matter with nose hairs and the moist mucos membrane lining of the respiratory system

• digestive system uses the acids and enzymes produced by the stomach to destroy invaders that are swallowed or consumed with food

• lymphatic system and specialized leukocytes

first line of defense

involves binding antigens to antibodies - this reaction labels a potentially dangerous antigen so it can be recognized and destroyed by other cells of the immune system

• the immune system immediately responds to the presence of any antigen

antigen-antibody reaction (immune reaction)

refers to an acquired unresponsiveness to a specific antigen - the term is also used to describe a decline in the effective response to a drug, usually due to a repeated use

tolerance

is a disease-fighting protein created by the immune system in response to the presence of a specific antigen

antibody (immunoglobulin)

bind with specific antigens in the antigen-antibody response - the five primary types, which are secreted by plasma cells, are also known as antibodies

immunoglobulins

is the most abundant class of antibodies, and are found in blood and lymph - these antibodies are active against bacteria, fungi, viruses, and foreign particles

immunoglobulin G (IgG)

is the class of antibodies produced predominantly against ingested antigens - these antibodies are found in body secretions such as saliva, sweat, or tears, and they function to prevent the attachment of viruses and bacteria to the epithelial surfaces that line most organs

immunoglobulin A (IgA)

is the class of antibodies that are found in circulating body fluids - these are the first antibodies to appear in response to an initial exposure to an antigen

immunoglobulin M (IgM)

is the class of antibodies found only on the surface of b cells - these antibodies are important in b cell activation

immunoglobulin d (IgD)

is the class of antibodies produced in the lungs, skin, and mucous membranes - these antibodies are responsible for allergic reactions

immunoglobulin e (IgE)

are specialized leukocytes that act as part of the antigen-antibody reaction by destroying substances such as cell debris, dust, pollen, and pathogens by the process of phagocytosis

phagocytes

is the process of destroying pathogens by surrounding and swallowing them

phagocytosis

are leukocytes that provide immunological defenses against many infectious organisms

• when they leave the bloodstream and enter into the tissue, they become macrophages and dendritic cells

monocytes

is a type of leukocyte that surrounds and kills invading cells

• also remove dead cells and stimulate the action of other immune cells

macrophage

are specialized leukocytes that patrol the body searching for antigens that produce infections - when such a cell is found, the dendritic cell grabs it, swallows it, and alerts b and t cells to act against this specific antigen

dendritic cells

is a group of proteins that normally circulate in the blood in an inactive form - when needed, these cells complement the abilitiy of antibodies to ward off pathogens by combining with them to dissolve and remove pathogenic bacteria and other foreign cells

complement system

is the state of being resistant to a specific disease - this resistance can be present naturally, or it can be acquired

immunity

is resistance to a disease present without the administration of an antigen or exposure to a disease

• is present at birth, and can be augmented when breast milk passes from a nursing mother to her baby

natural immunity (aka passive immunity)

is obtained by having had a contagious disease

• being vaccinated against a contagious disease provides protection against that disease, such as measles or polio, without having been exposed to the risk of actually having the disease

acquired immunity

is a preparation containing an antigen, consisting of whole or parital disease-causing organisms, which have been killed or weakened

vaccine

provides protection against the disease; however, for some conditions a periodic booster is required to maintain the effectiveness of the immunization

vaccination

specializes in diagnosing and treating conditions of altered immunologic reactivity, such as allergic reactions

allergist

is a physician who specializes in diagnosing and treating diseases caused by microorgansims such as viruses, bacteria, and parasites

infectious disease specialist

specializes in diagnosing and treating disorders of the immune system

immunologist

is a physician who specializes in diagnosing and treating disorders of the lymphatic system

lymphologist

is a physician who specializes in diagnosing and treating malignant disorders such as tumors and cancer

oncologist

is an inflammation of the lymph nodes

lymphadenitis (swollen glands)

is any disease process affecting a lymph node or nodes

lymphadenopathy

is a benign tumor formed by an abnormal collection of lymphatic vessels due to a congenital malformation of the lymphatic system

lymphangioma

is a medical emergency that occurs when the covering of the spleen is torn, usually as the result of a blow to the abdomen

ruptured spleen

is an abnormal enlargement of the spleen

• this condition can be due to bleeding caused by an injury, and infectious disease such as mononucleosis, or abnormal functioning of the immune system

splenomegaly

is a diagnositc test that is performed to detect damage or malformations of the lymphatic vessels - a radioactive substance is injected into lymph ducts, and a scanner or probe is used to follow the movement of the substance on a computer screen

lymphoscintigraphy

is swelling of the tissues due to an abnormal accumulation of lymph fluid within the tissues - this is not the type of swelling that occurs due to an injury such as a sprained ankle

• it is caused by damage to the lymphatic system that prevents lymph from draining properly

• because lymph is rich is protein, which is an environment that pathogens thrive in, lymphedema is often associated with infections

lymphedema

is a herediatry condition of the lymphatic system that develops with swelling beginning in the feet and progressing into the ankles and in an upward direction along the legs - the disorder occurs most frequently in females and the symptoms begin to appear during puberty

primary lymphedema

is caused by damage to lymphatic vessels that is most frequently due to cancer treatment, surgery, trauma, or burns

secondary lymphedema

uses specialized clothing such as socks, stockings, and sleeves or bandages to exert pressure, which can be used to improve circulation and lymph flow - although this treatment helps, at this time it is not possible to cure lymphedema

compression

is a noninvasive method of diagnosing lymphedema - it measures the resistance to an electrical current passed through the affected limb, with abnormally low results showing a buildup of lymph

• if this condition can be diagnosed with this technique at an early stage, there is hope that it will not develop any further

bioimpedance spectroscopy

the effectiveness of the immune system depends upon the individuals:

• general healh

• age

• heredity

occurs when the body’s immune system reacts to a harmless allergen such as pollen, food, or animal dander as if it were a dangerous invader

allergic reaction

is an overreaction by the body to a particular antigen

allergy (aka hypersensitivity)

is a substance that produces an allergic reaction in an individual

allergen

includes redness, itching, and burning where the skin has come into contact with an allergen

• for example, contact with poison ivy can cause a localized allergic response in the form of an itchy rash

• although the body reacts mildly the first time it is exposed to the allergen, sensitivity is established, and future contracts can cause much more sever symptoms

localized allergic response (aka cellular response)

is a severe response to an allergen

• symptoms of this response develop quickly

• without prompt medical aid, the patient can die within a few minutes

systemic reaction (aka anaphylaxis or anaphylactic shock)

is a diagnositc test to identify commonly troublesome allergens such as tree pollen and ragweed

• swelling and itching indicate an allergic reaction

scratch test