Immunology Flashcards
Lymph fluid resembles plasma but contain as a much lower concentration of what?
Proteins
Primary lymphoid tissues and organs are site where lymphocytes are formed and mature; what are they?
Red bone marrow and thymus.
Secondary lymphoid tissues and organs are where lymphocytes are ____? They include what?
Activated. Include: tonsils, MALT, lymph nodes, and spleen.
MALT
Mucosa-associated lymphatic tissue (peyer’s patches, appendix, tonsils)
How to lymphatic capillaries differ from blood capillaries?
1) they are closed at one end rather than forming continuous tubes
2) have larger luminal diameters
3) have thinner walls
4) typically have a flattened or irregular outline
The endothelial cells of a lymphatic capillary are not bound tightly together, but the do ________. Acting as a _______.
Overlap.
One-way valve (preventing them from returning to the intercellular spaces)
Lacteals
Important lymphatic capillaries in the small intestine transport lipids absorbed by the digestive tract.
Cisterns chili
Base of the thoracic duct that is an expanded, saclike chamber; receives from inferior part of abdomen
Lymphedema
Obstruction of lymphatic vessels.
Lymphocytes account for ___% of circulating leukocytes. Three classes include:
20-40%.
1) thymus-dependent cells,
2) bone marrow-derived cells
3) NK cells
Terminal center
Contains dividing lymphocytes
List tonsils:
1) pharyngeal tonsil (adenoid) lies in the posterior superior wall of nasopharynx
2) L and R palatine tonsils @ post/int margin of oral cavity
3) L and R lingual tonsils
Aggregated lymphoid nodules, aka:
Peyer’s patches (MALT)
Fibrous partitions of lymph node are called:
Trabeculae
Blood vessels and nerves reach the lymph node at a shallow indentation called the _____.
Hilum.
Two set of lymphatic vessels, ____ and ____ are connected to each lymph node.
Afferent (bring to) and efferent (bring out)
The lymph node interior is divided into an ______ and ______, and a region in between the two called the ______.
Outer cortex, inner medulla, and a region between called the parcortex.
_______ cells in subcapsular space are involved in starting immune response.
Dendritic cells.
The periphery of the lymph node cortex contains ___ cells within _____, similar to those of the nodules.
B cells; germinal centers
Paracortex is dominated by ___ cells.
T cells
The medulla of lymph node contains ___ cells and ____>
B cells and macrophages.
“Involution” of thymus.
After puberty, the thymus diminishes in size and becomes increasingly fibrous and fatty.
Thymic (Hassall’s) corpuscles
Epithelial reticular cells in the medulla of thymus that cluster together in concentric layers.
The cortex of thymus contains actively dividing ________ cells. A blood thymus barrier separates these developing cells from general circulation.
T lymphocytes. Medulla of thymus has no blood barrier and mature T cells leave after about 3 weeks.
3 functions of the spleen:
1) removing abnormal blood cells via phagocytosis
2) storing iron from recycled blood cells
3) initiating immune responses by B cells and T cells in response to antigens in circulating blood.
Red pulp (spleen):
Contains large quantities of RBCs; macrophages scattered throughout
White pulp (spleen)
Resembles lymphoid nodules; high concentration of lymphocytes and dendritic cells.
Immunity:
The body’s ability to resist and defend against infections organisms or other substances that could damage tissues and organs.
“Resistance”
Ability of the body to maintain immunity
Types of immunity:
1) innate (non-specific): skin, NK cells
2) adaptive (specific): T and B cells (respond to specific antigens) and defend against specific pathogens
Lymphocytopoiesis occurs where?
Red bone marrow, thymus, and peripheral lymphoid tissues.
Hemocytoblasts divide in the red bone marrow of adults to generate the lymphoid stem cells that produce all types of lymphocytes.
One group of lymphoid stem cells remain in red bone marrow and other group migrates to thymus.
Lymphoid stem cells in the red bone marrow divide to produce immature ____ cells and ____ cells.
B cells and NK cells.
Interleukin-7 (cytokine)
Produced by stromal cells of red bone marrow; promotes the differentiation of B cells.
Mature B cells move into ____, _____, or ____.
Lymph nodes, the spleen, or other lymphoid tissues.
NK cells move through _____ tissues in search of abnormal cells.
Peripheral.
When stimulated, ___ cells can differentiate into ____ cells, which produce and secrete _____.
B cells; plasma cells; antibodies, which attach to pathogens, creating a chain reaction that leads to the destruction of the pathogen.
Immune surveillance and the secretion of lysing chemicals performed by:
NK cells
Antibody-mediated immunity performed by:
B cells
Cell-mediated immunity performed by:
T-cells
Innate defenses (list 7):
1) physical barriers
2) phagocytes
3) immune surveillance
4) interferons
5) complement
6) inflammation
7) fever
Interferons
Released by activated lymphocytes, macrophages, or virus-infected cells; are the chemical messengers that coordinate the defenses against viral infections.
Inflammation and mast cell(s) limit the spread of injury/infection via (list 7):
1) increases blood flow
2) activates macrophages
3) increases capillary permeability
4) activates complement
5) stimulates regional clotting factors
6) increases regional temp
7) activates adaptive defenses