The Lymphatic and Immune System Flashcards
is the complex collection of cells and organs that destroys invaders that could cause disease or death.
immune system
is the system of vessels, cells, and organs that carries excess fluids to the bloodstream and filters pathogens from the blood. Its primary function is to regulate fluid levels throughout the body
lymphatic system
- is the term used to describe interstitial fluid once it has entered the lymphatic system
- carried in a series of vessels that merge together, similar to veins.
Lymph
the area may appear swollen and, if left unresolved, may lead to serious medical consequences
edema
- The smallest lymphatic vessels
- which feed into larger and larger lymphatic vessels, and eventually empty into the bloodstream via a series of ducts.
- are vessels where interstitial fluid enters
the lymphatic system. - are composed of overlapping endothelial cells.
Lymphatic Capillaries
is one of the several small, bean-shaped organs located throughout the lymphatic system.
lymph node
The lymph from the rest of the body enters the bloodstream through the ____________
via all the remaining lymphatic trunks.
thoracic duct
Located in almost every tissue in the body, these vessels are interlaced among the arterioles and venules of the circulatory system in the soft connective tissues of the body
lymph fluid
- In the small intestine, lymphatic capillaries called__________
- are critical for the transport of dietary lipids and lipid-soluble vitamins to the bloodstream.
lacteals
receives lymph from only the upper right side of the body.
right lymphatic duct
a saclike chamber that receives lymph from the lower abdomen, pelvis, and lower limbs by way of the left and right lumbar trunks and the
intestinal trunk.
cisterna chyli
- The smaller lymphatic vessels eventually merge to form larger lymphatic vessels
known as - On the right side of the body, the right sides of the head and thorax, as well as the right upper limb, drain lymph fluid into the right subclavian vein via the right lymphatic duct.
lymphatic trunks
function to remove debris and pathogens from the lymph, and are thus sometimes referred to
as the “filters of the lymph”
Lymph nodes
The major routes into the lymph node are via
afferent lymphatic vessels
Cells and lymph fluid that leave the lymph node may do so by another set of vessels known as the
efferent lymphatic vessels
Lymph enters the lymph node and first flows through the filtration zone, anatomically known as the ________________ which is occupied by cells that are capable of engulfing and destroying bacteria and debris.
subcapsular sinus
have a simpler architecture than the lymph nodes. They do not have a capsule, but instead
are a dense cluster of lymphocytes lodged within the walls of other tissues.
Lymphoid Nodules
Lymph then flows through the dividing zone, or ___________, which consists of follicles (gatherings of rapidly dividing lymphocytes)
cortex
- are specific lymphoid nodules located along the inner surface of the throat and are important in developing immunity to oral pathogens
- sometimes referred to as adenoids when swollen
Tonsils
tonsils do not contain a complete capsule, and the epithelial layer invaginates deeply into the interior of the tonsil to form ______________. These crevices accumulate all sorts of materials taken into the body through eating and breathing.
tonsillar crypts
- is a widely distributed group of lymphoid nodules found within this layer in the gastrointestinal tract, breast tissue, lungs, and eyes
- contain specialized cells that sample material from the intestinal lumen and transport it to nearby follicles so that adaptive immune responses to potential pathogens can be mounted.
Mucosa-associated lymphoid tissue (MALT)
consists of lymphoid follicular structures found along the walls of the bronchi in the lungs. These tissues, in addition to the tonsils, are effective against inhaled pathogens.
Bronchus-associated lymphoid tissue (BALT)
is a lymphoid organ which is larger and has a more complex structure than a lymph node. The thymus is found in the space between
the sternum and the aorta of the heart
thymus
- is a major lymphoid organ. It is found
in the posterior abdominal cavity, posterior to the stomach - wrapped in a thin capsule but is somewhat fragile due to its extensive vascularization.
- it filters blood rather than lymph.
spleen
- The red area is referred to as ___________ and consists mostly of red blood cells.
- monitors for the age and quality of red blood cells, taking old or damaged cells out of circulation.
red pulp
- The purplish area is called __________ and is filled with leukocytes.
- monitors the blood for the presence of bloodborne pathogens.
white pulp
The rapid “emergency responders” of the _____________________. A variety of cells and soluble factors that activate quickly but have limited efficacy
innate immune response
The slower but more specific and effective _________________________, which involves many cell types and soluble factors and is notable for its long-lasting memory capability.
adaptive immune response
Can ingest pathogens or other cellular debris for destruction. Mostly involved in the innate immune response, but many of them are capable of kickstarting the adaptive immune response
Phagocytic cells
A specialized class of leukocytes, which coordinate the activities of adaptive immunity
Lymphocytes
—an enzyme that destroys bacteria by
digesting their cell walls.
lysozyme
Cells that containing granules, which are packets of noxious materials that can be released in an attack against pathogens.
Granular cells
, the destruction of debris or pathogens through engulfment, is a central tool in the immune system fight
Phagocytosis
is an irregularly shaped phagocytic cell that is the most versatile of the phagocytes in the body.
Macrophages
though fewer in number, play very similar roles to macrophages.
Dendritic cells
are a type of white blood cell found in tremendous numbers in the bloodstream. Both granular cells and phagocytic cells.
Neutrophils
type of lymphocyte that have the ability to
induce apoptosis, or programmed cell death, in cells infected with intracellular pathogens such as viruses.
Natural Killer (NK) Cells
Basophils and eosinophils are _____________that circulate in the blood. Their granules contain chemicals that are particularly harmful to parasitic infection.
Granulocytes
form of granulocyte, that lives only in the tissue
mast cell
granules of mast cells primarily contain _____________, an important cytokine in the inflammation pathway
histamine
signaling molecules with a wide range of effects, including stimulating nociceptors to send pain signals to the CNS
prostaglandins
The two big functional differences between the innate and adaptive responses can be summarized with the words time and specificity.
● Time: Whereas the innate response can kick in immediately or within hours of infection, the adaptive immune response takes several days to be effective. The adaptive immune response, in fact, typically requires the innate immune response to activate it, so it always is effective later in infections with novel pathogens.
● Specificity: The adaptive immune response is exquisitely specific in its ability to recognize details of pathogens. For example, the adaptive immune response is tailored not just to one pathogen compared to another—such as influenza virus instead of Ebola virus—but can distinguish even between different versions of the same pathogen, such as the alpha and delta variants of SARS-COV-2. The
innate immune response, on the other hand, recognizes patterns of pathogenrelated molecules, such as bacterial cell wall components. In this way, the innate immune system responds to all bacteria in the same way. Innate immune cells use pattern recognition receptors to recognize common features of pathogens.
BASAHINNNNNNNNN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
is a membrane-bound receptor that recognizes characteristic features of a pathogen or molecules released by stressed
or damaged cells.
pattern recognition receptor (PRR)
Is a signaling molecule that allows cells to
communicate with each other over short distances. Secreted into the intercellular space, and the action induces the receiving cell to change its physiology.
cytokine
are one group of cytokines that are used by cells infected with viruses.
Interferons
is a soluble chemical mediator similar to cytokines except that its function is to attract cells (chemotaxis) from longer distances.
chemokine
is a series of proteins that are always
found in the blood plasma.
Complement System
is the tagging of a pathogen for phagocytosis by the binding of an antibody or an antimicrobial protein.
Opsonization
The hallmark of the innate immune response is _____________. Is something everyone has experienced.
Inflammation
There are four parts to the inflammatory response:
● Tissue Injury. The released contents of injured cells stimulate the release of mast cell granules and their potent inflammatory mediators. Histamine increases the diameter of local blood vessels (vasodilation), causing an increase in blood flow to the injured site. Histamine also increases the permeability of local capillaries, causing more plasma than usual to leak out and form interstitial fluid. This causes the swelling associated with inflammation.
● Vasodilation. Prostaglandins and histamine are vasodilators that increase the diameters of local capillaries. This causes increased blood flow and is responsible for the heat and redness of inflamed tissue. It allows greater access of the blood and the cells that travel in blood to the site of inflammation.
● Increased Vascular Permeability. These and other cytokines increase the permeability of the capillaries, which allows the cells to exit the blood more easily. A side effect of this increased permeability is the leakage of fluid into the interstitial space, resulting in the swelling, or edema, associated with inflammation.
● Recruitment of Phagocytes. Neutrophils flock in incredible numbers to the site of injury, where they can phagocytose any infiltrated pathogens and kill the invader along with themselves. Monocytes, the precursors to macrophages, also are recruited by the inflammatory cytokines. Once they exit the blood vessel, they mature into macrophages, enabling them to participate in both the
cleanup of debris from the injury and the immune response.
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an increase of more than 1oC (1.8oF) above the set point for body temperature, is a very useful tool of the innate immune system.
Fever
the molecules or groups of molecules that the body does not recognize as belonging to the “self,” are recognized by receptors on the sur
face of B and T lymphocytes.
Antigens
are those enacted by the cells themselves.
Cellular responses
are the set of actions made possible by antibodies,
Antibody-mediated responses
secreted proteins of the adaptive immune
response
antibodies
The immune system’s first exposure to
a pathogen elicits a _____________________.
primary response
often eliminates a pathogen before it can cause significant tissue
damage or any symptoms.
secondary adaptive response
This secondary response is the basis of _______________, which protects us from getting diseases repeatedly from the same pathogen.
immunological memory
A third important feature of the adaptive immune response is its ability to distinguish between self-antigens—those that are normally present in the body—and foreign antigens
Self Recognition
are particularly important, as they not only control a multitude of immune responses directly but also influence B cell responses.
T cells
The end of the receptors furthest from the cell membrane features the _____________, which is formed by both of the two chains of proteins that form the receptor.
antigen-binding site
is one of the small regions within an antigen to which a receptor can bind, and limited by the size of the receptor itself.
antigenic determinant
on pathogens are usually large and complex, and consist of many individual characteristics, called antigenic determinants.
Antigens
They only recognize antigens on the surface of specialized cells called
antigen-presenting cells (APCs)
The antigen fragments are then brought to the cell’s surface by an antigen-presenting protein known as a _____________ molecule.
major histocompatibility complex (MHC)
It is not that we never produce self reactive lymphocytes, but that we have a process of eliminating T cells that might attack our own antigens, referred to as
T cell tolerance.
This proliferation of T cells is called __________ and is necessary to make the immune response strong enough to effectively control a pathogen
clonal expansion
is the process of antigen binding only to those T cells that have receptors specific to that antigen.
Clonal selection
are long-lived and can even persist for decades. Memory cells are primed to act rapidly.
Memory T cells
function by secreting cytokines that act
to enhance other immune responses.
Helper T cells (CD4+ T cells)
are T cells that kill target cells by inducing apoptosis, using a similar mechanism as NK cells.
Cytotoxic T cells (CD 8 T cells)
are a specialized type of helper T cell.
Regulatory T cells
There are five different classes of antibody found in humans:
IgM, IgD, IgG, IgA, and IgE.
that are specific for antigen, just like T cells.
B cell receptors
is described as a pentamer, a molecule with five distinct subunits. It resembles a star with five individual antibody structures that meet at their Fc regions. Usually the first antibody made during a primary response.
IgM
is a major antibody of late primary responses and the main antibody of secondary responses in the blood. This is because class switching occurs during primary responses.
IgG
is usually associated with allergies and anaphylaxis. It is present in the lowest
concentration in the blood, but is found in much higher concentrations in interstitial
fluid.
IgE
exists in two forms, but is most often found as a dimer, a structure consisting of two antibodies joined at their Fc regions.
IgA
is mostly found expressed on B cell plasma membranes, but is secreted in very
small amounts into the bloodstream.
IgD
is the process of coating a pathogen with antibodies, making it physically impos
sible for the pathogen to bind to receptors.
Neutralization
is the resistance to pathogens acquired during an adaptive immune response within an individual
Active immunity
arises from the transfer of antibodies to an individual without requiring them to mount their own active immune response.
Passive immunity
