PNB 2265 Practical 1 || 100% Exact Solutions.
What are the two main functions of the lymphatic system? correct answers The two main
functions of the lymphatic system are
1. to return fluid from the interstitial spaces to the circulatory system, thus maintaining blood
volume. (fluid balance)
2. to assist in body's defense against disease.
What are the components of the lymphatic system? correct answers The components of the
lymphatic system are
1. Lymph vessels
- Lymph
2. Lymphoid tissues
3. Lymphoid organs
- Spleen
- Lymph Nodes
- Thymus
What are the primary functions of the Primary (Central) lymphoid organs? correct answers The
Primary Lymphoid Organs produce lymphocytes from immature progenitor cells.
The Thymus and the Bone Marrow constitute the Primary lymphoid organs involved in the
production and early selection of lymphocyte tissues.
What are the primary functions of the Secondary (Peripheral) lymphoid organs? correct answers
The Secondary or Peripheral lymphoid organs maintain mature naive lymphocytes and initiate an
adaptive (antigens the body has never seen before) immune response.
The Lymph Nodes, Spleen, Tonsils
Indicate the Red and White pulp on a Spleen slide correct answers The white pulp can be
organized as splenic (lymph) nodules with the characteristic central artery (arteriole) in each
nodule. The germinal centers contains rapidly dividing B lymphocytes.
The rest of the cortical cells which are not organized as nodules are primarily T lymphocytes that
circulate continuously, moving from the blood into the spleen and then exiting from the spleen
into the lymphatic system.
Both red and white pulp are supported by reticular fibers that form a supporting framework of
the spleen.
,Red Pulp - serves as site of storage of RBCs and filters them
White Pulp - clusters of T cells, B cells and Macrophages
What is the role of a B Cell in the immune response? correct answers Humoral immunity /
antibody mediated immunity
Immunity conferred to an individual through the activity of B cells and their progeny, which
produce circulating antibodies in response to the presence of a foreign substance and recognize
the substance upon renewed exposure. Expand.
What is the role of a T Cell in the immune response? correct answers Cellular immunity / cell
mediated immunity
Cell-mediated immunity is an immune response that does not involve antibodies, but rather
involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release
of various cytokines in response to an antigen.
How does the Hemolytic Plaques Assay Demonstrate the presence of antibody-producing plasma
cells? correct answers (refer to The Immunization Process)
To visualize the effect of this response, the spleen (a source of B-cells) is removed from the
mouse, and lymphocytes are isolated by homogenization and centrifugation.
The lymphocytes, composed in part of B-cells, are mixed with target cells (SRBC's),
complement (from guinea pig serum), and a buffer which serves to maintain proper physiological
conditions.
This mixture is pipetted into a microchamber formed between a glass microscope slide and a
coverslip. This very narrow chamber allows the cells to settle as a monolayer.
Both the B-cells and the target cells are held in place in the liquid matrix by adhesion, while the
antibodies and complement are free to diffuse.
The edges of the chambers are sealed with wax to prevent drying during the incubation period.
After incubation, the chambers are observed for the presence of plaques.
A positive result (indicating an "activated" immune response by the mouse) will reveal small,
clear pinholes in the pink monolayer matrix. These clear zones, or plaques, are regions around
individual antibody-producing cells where the target cells (SRBC) have been lysed. These
plaques can be seen more clearly under a microscope. In addition, a single B-cell can usually be
seen in the center of each plaque, often with a cluster of dead target cells adhering to its surface
in what is known as a "rosette formation."
, The number of plaques present will determine the number of antibody-secreting B-cells in a
population of lymphocytes.
Summary:
- Used to detect antibody-producing plasma cells
- Mice are immunized with sheep red blood cells (SRBC)
- Stimulates B cells in the mouse spleen to differentiate into plasma cells and secrete antibodies
against SRBC
Spleen correct answers Secondary Lymph Organ
Main function is to cleanse the blood of defective blood cells.
Site of initiation of immune response
Lymph Nodes correct answers Secondary Lymph Organ
Lymphocytes in nodes assist in activating immune response
Thymus correct answers Primary Lymph Organ
Development of T lymphocytes
Hassell's Corpuscles (view on slide)
Histology
-Bilobed
-Between sternum and aorta
-Capsule- connective tissue
-Cortex- T cells, dendritic cells, macrophages, epithelial cells
-Medulla- more mature T cells, macrophages, dendritic cells
-Hassall's corpuscles
Lymphocytes correct answers B cells and T cells
Explain the steps in an INDIRECT E.L.I.S.A. correct answers Enzyme Linked ImmunoSorbent
Assay (ELISA)
Utilizes the basic principles of antibody-mediated immunity to detect antibodies or antigens in a
sample
Important diagnostic tool to detect infection with specific pathogens
- Extremely sensitive
- Extremely specific
What are the two main functions of the lymphatic system? correct answers The two main
functions of the lymphatic system are
1. to return fluid from the interstitial spaces to the circulatory system, thus maintaining blood
volume. (fluid balance)
2. to assist in body's defense against disease.
What are the components of the lymphatic system? correct answers The components of the
lymphatic system are
1. Lymph vessels
- Lymph
2. Lymphoid tissues
3. Lymphoid organs
- Spleen
- Lymph Nodes
- Thymus
What are the primary functions of the Primary (Central) lymphoid organs? correct answers The
Primary Lymphoid Organs produce lymphocytes from immature progenitor cells.
The Thymus and the Bone Marrow constitute the Primary lymphoid organs involved in the
production and early selection of lymphocyte tissues.
What are the primary functions of the Secondary (Peripheral) lymphoid organs? correct answers
The Secondary or Peripheral lymphoid organs maintain mature naive lymphocytes and initiate an
adaptive (antigens the body has never seen before) immune response.
The Lymph Nodes, Spleen, Tonsils
Indicate the Red and White pulp on a Spleen slide correct answers The white pulp can be
organized as splenic (lymph) nodules with the characteristic central artery (arteriole) in each
nodule. The germinal centers contains rapidly dividing B lymphocytes.
The rest of the cortical cells which are not organized as nodules are primarily T lymphocytes that
circulate continuously, moving from the blood into the spleen and then exiting from the spleen
into the lymphatic system.
Both red and white pulp are supported by reticular fibers that form a supporting framework of
the spleen.
,Red Pulp - serves as site of storage of RBCs and filters them
White Pulp - clusters of T cells, B cells and Macrophages
What is the role of a B Cell in the immune response? correct answers Humoral immunity /
antibody mediated immunity
Immunity conferred to an individual through the activity of B cells and their progeny, which
produce circulating antibodies in response to the presence of a foreign substance and recognize
the substance upon renewed exposure. Expand.
What is the role of a T Cell in the immune response? correct answers Cellular immunity / cell
mediated immunity
Cell-mediated immunity is an immune response that does not involve antibodies, but rather
involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release
of various cytokines in response to an antigen.
How does the Hemolytic Plaques Assay Demonstrate the presence of antibody-producing plasma
cells? correct answers (refer to The Immunization Process)
To visualize the effect of this response, the spleen (a source of B-cells) is removed from the
mouse, and lymphocytes are isolated by homogenization and centrifugation.
The lymphocytes, composed in part of B-cells, are mixed with target cells (SRBC's),
complement (from guinea pig serum), and a buffer which serves to maintain proper physiological
conditions.
This mixture is pipetted into a microchamber formed between a glass microscope slide and a
coverslip. This very narrow chamber allows the cells to settle as a monolayer.
Both the B-cells and the target cells are held in place in the liquid matrix by adhesion, while the
antibodies and complement are free to diffuse.
The edges of the chambers are sealed with wax to prevent drying during the incubation period.
After incubation, the chambers are observed for the presence of plaques.
A positive result (indicating an "activated" immune response by the mouse) will reveal small,
clear pinholes in the pink monolayer matrix. These clear zones, or plaques, are regions around
individual antibody-producing cells where the target cells (SRBC) have been lysed. These
plaques can be seen more clearly under a microscope. In addition, a single B-cell can usually be
seen in the center of each plaque, often with a cluster of dead target cells adhering to its surface
in what is known as a "rosette formation."
, The number of plaques present will determine the number of antibody-secreting B-cells in a
population of lymphocytes.
Summary:
- Used to detect antibody-producing plasma cells
- Mice are immunized with sheep red blood cells (SRBC)
- Stimulates B cells in the mouse spleen to differentiate into plasma cells and secrete antibodies
against SRBC
Spleen correct answers Secondary Lymph Organ
Main function is to cleanse the blood of defective blood cells.
Site of initiation of immune response
Lymph Nodes correct answers Secondary Lymph Organ
Lymphocytes in nodes assist in activating immune response
Thymus correct answers Primary Lymph Organ
Development of T lymphocytes
Hassell's Corpuscles (view on slide)
Histology
-Bilobed
-Between sternum and aorta
-Capsule- connective tissue
-Cortex- T cells, dendritic cells, macrophages, epithelial cells
-Medulla- more mature T cells, macrophages, dendritic cells
-Hassall's corpuscles
Lymphocytes correct answers B cells and T cells
Explain the steps in an INDIRECT E.L.I.S.A. correct answers Enzyme Linked ImmunoSorbent
Assay (ELISA)
Utilizes the basic principles of antibody-mediated immunity to detect antibodies or antigens in a
sample
Important diagnostic tool to detect infection with specific pathogens
- Extremely sensitive
- Extremely specific
