Chapter 6 Flashcards
Lymph
The fluid that removes cellular waste products,
pathogens, and dead blood cells from
the tissues.is made up of the remaining 10% of
the returning interstitial fluid. Lymph is a clear, watery
fluid containing electrolytes and proteins. It plays essential
roles in the lymphatic system as it works in close
cooperation with the immune system.
n Lymph collects the protein molecules created within
the cells as it leaves. Lymph also removes dead cells,
debris, and pathogens (including cancer cells) that
were still left in the intercellular spaces.
n The lymph enters very small capillaries within the tissues
and then flows into progressively larger vessels
and ducts as it travels in a one-way trip upward toward
the neck.
n At this stage, the lymph begins to play an active role in
cooperation with the immune system to protect the
body against invading microorganisms and diseases.
These functions are described in the discussion of the
immune system.
Lymphatic vessels and ducts
The capillaries, vessels, and ducts that return
lymph from the tissues to the venous
bloodstream.
Lymph nodes
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.
Tonsils and Adenoids
Lymphoid structures of the lymphatic system
that protect the entry to the respiratory system.
Spleen
A sac-like mass of lymphoid tissue with
protective roles in both the immune and
lymphatic systems
The spleen filters microorganisms and other foreign
material from the blood.
n The spleen forms lymphocytes and monocytes, which
are specialized leukocytes (white blood cells) with
roles to play in the immune system.
n The spleen has the hemolytic (hee-moh-LIT-ick)
function of destroying worn-out erythrocytes (red
blood cells) and releasing their hemoglobin for reuse
(hem/o means blood, and -lytic means to destroy).
n The spleen also stores extra erythrocytes (red blood
cells) and maintains the appropriate balance between
these cells and the plasma of the blood
Bone Marrow
Produces lymphocytes, which are specialized
leukocytes (white blood cells). Myel/o also
means spinal cord
Lymphocytes
Specialized leukocytes that play important
roles in the immune reactions.
Thymus
A gland located in the upper chest with
specialized roles in both the lymphatic and
immune systems.
anti-
against
carcin/o
cancerous
immune/o
immune, protection, safe
lymph/o
lymph, lymphatic tissue
lymphaden/o
lymph node or gland
lymphangi/o
lymph vessel
neo-
ne/o
new, strange
-oma
tumor, neoplasm
onc/o
tumor
phag/o
eat, swallow
-plasm
formative material of cells
sarc/o
flesh, connective tissue
spleen/o
spleen
-tic
pertaining to
tox/o
poison, poisonous
lymphatic system
- Absorb fats and fat-soluble vitamins through the lacteals
of the small intestine. - Remove waste products from the tissues, and cooperate
with the immune system in destroying invading
pathogens. - Return filtered lymph to the veins at the base of the
neck.
Lacteals
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
interstitial fluid
plasma blood that flows out of the arterioles and into the capillaries,
and then flows into the spaces between the cells of
the tissues.
n This fluid delivers nutrients, oxygen, and hormones to
the cells.
n When interstitial fluid leaves the cells, it brings with it
waste products and protein molecules that were created
within the cells. About 90% of this fluid returns to
the bloodstream.
Cool Lymph facts
Blood circulates throughout the entire body in a loop,
pumped by the heart. The bloodstream flows in an
open system in which it leaves and reenters the blood
vessels through the capillaries
n Since the lymphatic system does not have a pump-like
organ, it must depend on the pumping motion of
muscles to move the fluid upward.
n Lymph flows in only one direction. From its point of
origin, lymph can move only upward until it returns
to the circulatory system at the base of the neck.
Once lymph enters a lymphatic capillary, it must
continue this upward flow.
n Blood is filtered by the kidneys, and waste products
are excreted by the urinary system. Lymph is filtered
by lymph nodes, which are located along lymphatic
vessels. These nodes contain specialized cells of the
immune system.
n The color of blood makes the arteries and veins readily
visible. Since lymph is a clear fluid, the lymphatic
vessels are not readily visible.
Lymphatic Capillaries
are microscopic, blind-ended
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 vessels
which are located
deeper within the tissues. Like veins, lymphatic vessels
have valves to prevent the backward flow of lymph.
The larger lymphatic vessels eventually join together
to form two ducts. Each duct drains a specific part of the
body and returns the lymph to the venous circulation
cervic
neck
axill
armpit
inguin
groin
Natural killer cell
NK cells) play an important role in
the killing of cancer cells and cells infected by viruses.
B cells
also known as B lymphocytes, are specialized
lymphocytes that produce antibodies. Each lymphocyte
makes a specific antibody that is capable of
destroying a specific antigen.
n B cells are most effective against viruses and bacteria
that are circulating in the blood. When a B cell is
confronted with the antigen that it is coded to destroy,
that B cell is transformed into a plasma cell.
n Plasma cells develop from B cells and secrete a large
volume of antibodies coded to destroy specific
antigens
T cells
also known as T lymphocytes, belong to a
group of leukocytes known as lymphocytes. These
cells, which get the ‘T’ in their name from their origin
in the thymus, play a central role in cell-mediated
immunity.
tonsils
are three masses of lymphoid tissue
that form a protective ring around the back of the
nose and upper throat (Figure 6.4). The tonsils play an
important role in the immune system by preventing
pathogens from entering the respiratory system when
breathing through the nose and mouth.
palatine
describes the hard
and soft palates that form the roof of the mouth.
lingual
tongue
adenoids
also known as the
nasopharyngeal tonsils, are located in the nasopharynx,
which is the upper part of the pharynx
plasma cells
come from B cells and release antibodies
thymus
which is a mass of lymphoid
tissue located above the heart, reaches its greatest size at
puberty and becomes smaller with age.
n As part of the endocrine system, the thymus
secretes a hormone that stimulates the maturation
of lymphocytes into T cells
These T cells, which are essential to the immune system,
leave the thymus through the bloodstream and
the lymphatic system
tolerance
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 repeated use.
antigen
is any substance that the body
regards as being foreign. This includes viruses, bacteria,
toxins, and transplanted tissues. The immune system
immediately responds to the presence of any antigen
antibody/ immunoglobins
is a disease-fighting
protein created by the immune system in
response to the presence of a specific antigen
(the prefix anti- means against). The terms
antibody and immunoglobulin are often used
interchangeably.
immunoglobin G
is the most abundant class of antibodies, and they are found in blood serum and lymph. These antibodies are active against bacteria, fungi, viruses, and foreign particles.
Imunoglobin A
is the class of antibodies produced predominantly against ingested antigens. These antibodies are found in body secretions such as saliva, sweat, or tears, and function to prevent the attachment of viruses and bacteria to the epithelial surfaces that line most organs.
immunoglobin M
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.
Immunoglobin D
the class of antibodies found only on the surface of B cells. These antibodies are important in B cell activation.
Immunoglobin E
is the class of antibodies produced in the lungs, skin, and mucous membranes. These antibodies are responsible for allergic reactions.
phagocytes
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
monocytes (type of phagocyte)
are leukocytes that provide immunological
defenses against many infectious organisms. Macrophages
derive from monocytes after they leave the
bloodstream and enter into the tissue. Monocytes
replenish macrophages and dendritic cells.
macrophage (phagocyte)
a type of leukocyte
that surrounds and kills invading cells (macro- means
large, and -phage means a cell that eats). Macrophages
also remove dead cells and stimulate the action
of other immune cells.
-phage
a cell that eats
dendritic cells
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, and alerts B and T
cells to act against this specific antigen.
-edema
swelling
Primary lymphedema
is a hereditary 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 occursmost
frequently in females when the symptoms begin to appear
during puberty.
Secondary Lymphedema
is caused by damage to
lymphatic vessels that is most frequently due to cancer
treatment, surgery, trauma, or burns
localized allergic response
also known as a cellular
response, 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
(see Chapter 12). Although the body reacts mildly the
first time it is exposed to the allergen, sensitivity is
established, and future contacts can cause much more
severe symptoms.
autoimmune disorder
is any of a large
group of diseases characterized by a condition in which
the immune system produces antibodies against its own
tissues, mistaking healthy cells, tissues, or organs for
antigens.
immunodeficiency disorder
occurs when the immune response is
compromised. Compromised means weakened or not
functioning properly.
HIV
is a bloodborne
infection in which the virus damages or kills the T cells of the
immune system, causing it to progressively fail, thus leaving
the body at risk of developing many life-threatening
opportunistic infections (Figure 6.9). Medical intervention
including reverse transcriptase (RT), protease, and fusion
inhibitors can now prolong the patient’s life, especially if
administered starting in the early stages of HIV
opportunistic infection
is
caused by a pathogen that does not normally produce
an illness in healthy humans. However, when the host
is debilitated, these pathogens are able to cause an
infection. Debilitated means weakened by another
condition.
Bacilli
are rod-shaped spore-forming
bacteria (bacilli means rod shaped). (The singular is
bacillus.)
Anthrax
is a contagious disease that can
be transmitted through livestock infected with bacillus
anthracis. Spores grown in laboratories have been
used in biological warfare.
spirochetes
are long, slender spiralshaped
bacteria that have flexible walls and are capable
of movement.
rickettisa
is a small bacterium that
lives in lice, fleas, ticks, and mites (plural, rickettsiae).
Rocky Mountain spotted fever is caused by a rickettsia
that is transmitted to humans by the bite of an infected
tick
staphylococci
are a group
of about 30 species of bacteria that form irregular
groups or clusters resembling grapes (staphyl/o
means clusters or bunches of grapes, and -cocci
means spherical bacteria). (The singular is
staphylococcus.) Most staphylococci are harmless
and reside normally on the skin and mucous membranes
of humans and other organisms; however,
others are capable of producing very serious
infections.
immunosupression
is
treatment to repress or interfere with the ability of
the immune system to respond to stimulation by
antigens.
immunosuppressant
is a substance that prevents or reduces the body’s
normal immune response. This medication is administered
to prevent the rejection of donor tissue and to
depress autoimmune disorders
strept/o
twisted chain
-cocci
spherical bacteria
viruses
are very small infectious agents
that live only by invading other cells. After invading
the cell, the virus reproduces and then breaks the wall
of the infected cell to release the newly formed viruses.
These viruses spread to other cells and repeat the
process.
-genesis
reproduction
in situ
means in the place where the cancer first
occurred.
carcinoma
malignant tumor in epithelial tissue
sarcoma
malignant tumor that arises in connective tissues
lobules
milk glands
brachy-
short
tele-
distant
