Lymphatic System And Body Defenses Flashcards
Which of the following is not a normal component of lymph? Water, plasma proteins, red blood cells, ions
red blood cells
In the spleen, red pulp is involved in the immune functions and white pulp is involved in disposing of worn out RBCs. True or false?
False
From the right leg, lymph move in which order?
Right lumbar trunk, thoracic duct, left subclavian vein
Which of the following statements is false regarding the spleen? The splenic artery and vein enter and exit the spleen at the hilum clusters of white pulp look like islands in a sea of red pulp, red pulp is where immune functions take place, or the spleen is the largest lymphoid organ
RED PULP IS WHERE IMMUNE FUNCTIONS TAKE PLACE
About 3 L of fluid are lost to the tissue spaces every 24 hours and are returned to the bloodstream as lymph. True or false?
True
Peyer’s patches are clusters of lymphoid tissue found primarily in the large intestine. True or false
False
Which of the following would not be classified as a lymphoid organ? pancreas, spleen, tonsils, or Peyer’s patches of the intestine
PANCREAS
Helper T cells…
Function in the adaptive immune system activation
Which of the following is not a type of T cell? Cytotoxic, Helper, antigenic, Regulatory,
antigenic
Anaphylactic shock is a rare but severe allergic response that may occur if the allergen enters the bloodstream. True or false
True
The directional movement of cells in response to chemicals is called chemotaxis. True or false
True
After becoming immunocompetent, the naïve T cells and B cells are exported to the bone marrow where the encounters with antigens occur True or false
False
Soluble proteins secreted by plasma cells are called antibodies
True
Fever is often a beneficial immune response because it can speed the activities of leucocytes. True or false
True
Functions of the spleen include all of those below except removal of old or defective blood cells from the blood, forming crypts that trap bacteria, storage of blood platelets, or storage of iron
STORAGE OF IRON
What are the principal lymphoid organs?
Lymph nodes
What lymphoid organ filter lymph and helps activate the immune system?
lymph nodes
What are the 3 components of lymph nodes?
Fibrous capsule, a cortex, and a medulla
What is contained within the cortex and what is its main function?
Lymphocytes, which act in immune responses
What is contained within the medulla and what are its main functions?
Macrophages, which engulf and destroy viruses, bacteria, and other foreign debris, as well as lymphocytes
Lymph enters the lymph nodes via ____ vessels and exits via _____ vessels.
afferent lymphatic; efferent
There are few afferent vessels. True or false?
False; fewer efferent vessels
Why does lymph flow stagnate within the lymph node?
To allow time for its cleansing
Which lymphoid organ removes blood borne pathogens and aged red blood cells?
the spleen
Where does lymphocyte proliferation occur?
The spleen
What are three other functions of the spleen?
Recycles the breakdown products of hemoglobin, stores platelets and monocytes, and may be a hematopoietic site in the fetus
What is MALT and its main function?
mucosa-associated lymphoid tissue; guards the body’s entryways against pathogens
List some tissue components of MALT.
Peyer’s patches of the intestinal wall, lymphoid follicles of the appendix, tonsils of the pharynx and oral cavity, and follicles in the genitourinary and respiratory tract mucosa
Where do T lymphocytes mature and become immunocompetent?
The thymus
During fetal development, lymphatics develop as outpocketings of developing veins. True or false?
True
Other than the thymus, where do the other lymphoid organs derive from?
Mesenchymal cells of mesoderm. Thymus develops from endoderm
What is the first lymphoid organ to develop?
Thymus
Entry of lymph into the lymphatic capillaries is promoted by what?
One-way mini valves formed by overlapping endothelial cells and greater fluid pressure in the interstitial space
The structural framework of lymphoid organs is…
reticular tissue
The germinal centers in lymph nodes are largely sites of____
proliferating B lymphocytes
The red pulp areas of the spleen are sites of ____
Splenic sinusoids, macrophages, and red blood cells
The sac that often forms the initial portion of the thoracic duct is the ____
cisterna chyli
The white pulp areas of the spleen are where ___
immune functions take place; composed mostly of lymphocytes
What type of barriers act as the first line of defense token invaders out of the body? Give 2 examples.
Surface barriers, skin and mucous membranes
Surface membranes provide mechanical barriers to pathogens. Give some examples.
The skin’s acidity, lysozyme, mucus, keratin, and ciliated cells
Cells and chemicals that act as the second line of defense are an example of what?
The innate internal defense
What are the functions of phagocytes?
To engulf and destroy pathogens that breach epithelial barriers.
Name 2 phagocytes.
Macrophages and neutrophils
What are the functions of natural killer (NK) cells?
large granular lymphocytes that act nonspecifically to kill virus-infected and cancerous cells
What is the inflammation response?
a response that prevents the spread of harmful agents, disposes of pathogens and dead tissue cells, and promotes healing
What is the inflammatory process?
Exudate forms, protective leukocytes enter the area, fibrin walls off the area, and tissue repair occurs
What are the cardinal signs of inflammation?
swelling, redness, heat, and pain - all result from inflammatory chemicals that induce vasodilation and make blood vessels more permeable
What are interferons?
a group of related proteins (antimicrobial proteins) synthesized by virus-infected cells and certain immune cells that prevent viruses from multiplying in other body cells
What happens when complement is activated?
A group of plasma proteins (complement) on the membrane of a foreign cell promotes phagocytosis of that cell, enhances inflammation, and sometimes causes lysis of the target cell
What is the adaptive immune system?
It recognizes something as foreign and acts to immobilize, neutralize, or remove it
The adaptive immune system is considered the third line of defense. True or false?
True
What are three characteristics of the adaptive immune system?
It’s antigen-specific, systemic, and has memory
___ are substances that trigger the body’s adaptive defenses.
Antigens
Complete antigens have both immunogenicity and reactivity. True or False?
True
Incomplete antigens, or haptens, must….
combine with a body protein before coming immunogenic
What are antigenic determinants?
the portions of antigen molecules that are recognized as foreign
What are MHC proteins?
Major histocompatibility complex proteins are membrane-bound glycoproteins that mark our cells as “self”
What are the cells of the adaptive immune response?
B and T lymphocytes and antigen-presenting cells
All of the following are considered innate body defenses except complement, phagocytosis, antibodies, lysozyme, or inflammation
antibodies
The process by which neutrophils squeeze through capillary walls in response to inflammatory signals is called…
diapedesis
Antibodies released by plasma cells are involved in …
humoral immunity, immediate hypersensitivity reactions, and autoimmune disorders
Which of the antibodies can fix complement?
IgG & IgM
Small molecules that must combine with large proteins to become immunogenic are called…
haptens
Which antibody class is abundant in body secretions?
IgA
Lymphocytes that develop immunocompetence in the bone marrow are …
B lymphocytes
Cells that can directly attack target cells include all of the following except macrophages, cytotoxic T cells, helper T cells, natural killer cells
helper T cells
Which of the following is not involved in the activation of a B cell? antigen, helper T cell, cytokine, or cytotoxic T cell
cytotoxic T cell
The cell type most often invaded by HIV is a…
helper T cell
Complement fixation promotes all of the following except cell lysis, inflammation, opsonization, interferon release, or chemotaxis of neutrophils and other cells
interferon release
Which cells release perforins?
NK cells, cytotoxic T cells
Name 4 lymphocytes
NK cell, cytotoxic T cells, B cell, helper T cells
Name 2 effector cells of adaptive immunity
cytotoxic T cells, helper T cells
Name 3 antigen-presenting cells (APCs)
dendritic cells, B cells, macrophages
____ are educated to develop immunocompetence and self-tolerance.
Lymphocytes
___ are educated in the thymus and provide cellular immunity.
T cells
____ are educated in the bone marrow and provide humoral immunity.
B cells
Immunocompetence is signaled by what?
the appearance of antigen-specific receptors on the surface of the lymphocyte
Immunocompetent lymphocytes circulate in what 3 places?
blood, lymph, and lymphoid organs
What happens when naive lymphocytes encounter their antigen?
Clone selection, proliferation, and differentiation occur
What do “clone members” become?
mostly effector cells, but also memory cells
What are APCs function?
They internalize antigens and present antigenic determinants on their surfaces for recognition by T cells
In _____ immunity, antibodies are produced that target extracellular antigens.
humoral
When _____ are activated, most of the clone members become effector cells (plasma cells), which secrete antibodies
B cells
Give an example of a primary adaptive immune response.
Activation and differentiation of B cells
When memory cells mount a rapid attack against the same antigen in subsequent encounters, this is known as a …
Secondary immune response
Which cells provide humoral immunological memory?
Memory B cells
When is active humoral immunity acquired?
During an infection or via vaccination, providing immunological memory
When is passive immunity is acquired?
When a donor’s antibodies are injected into the bloodstream, or when the mother’s antibodies cross the placenta.
What do the constant regions of an antibody polypeptide chain determine?
antibody function and class
What do the variable regions of an antibody polypeptide chain determine?
they enable the antibody to recognize is specific antigen
Name 4 antibody functions.
complement fixation, antigen neutralization, precipitation, and agglutination
What are monoclonal antibodies?
Pure preparations of a single antibody type useful in diagnostic tests and treating some types of cancer
_____ immunity consists of T lymphocytes that direct adaptive immunity or attack cellular targets
Cellular
MHC proteins present antigens to….
T cells
What is the difference between class I MHC proteins and class II MHC proteins?
Class I proteins are found on all nucleated cells, while class II proteins are found only on APCs
What activates immunocompetent CD4 and CD8 T cells?
By binding to an antigen-MHC complex on the surface of an APC
A co-stiumulatory signal is essential for what process?
Activation of immunocompetent CD4 and CD8 T cells
The immune response is enhanced by cytokines such as….
interleukin 1 released by macrophages, and interleukin 2, gamma interferon, and others released by activated T cells
What are the roles of Helper T cells?
They are required for full activation of most B and T cells, activate macrophages, and release essential cytokines
What are the roles of cytotoxic T cells?
They directly attack and kill infected cells and cancer cells; together with NK cells, they conduct immune surveillance
What are the roles of regulatory T cells?
To help maintain tolerance
Development of the immune response occurs around what time?
Birth
The nervous system plays an important role in regulating immune response. True or false?
True
