Lecture Exam 2 - Lymphatic System Study Guide Flashcards
Terminology and Structure –
Define: Immunity
The body is continually exposed to toxins and pathogens (disease-inducing substances) including viruses, bacteria and environmental pollutants.
Our immune system allows us to defend against these harmful substances.
Terminology and Structure –
Define: resistance
The ability to ward off the pathogens that produce disease
Terminology and Structure –
Define: Susceptibility
Lack of resistance to pathogens that produce disease
Terminology and Structure –
Define: lymphatic system
The body system that carries out immune responses is the lymphatic system.
Terminology and Structure –
Define: non-specific (innate) immunity
Nonspecific resistance to disease includes
defense mechanisms that provide general
protection against invasion by a wide range of
pathogens.
Terminology and Structure –
Define: specific immunity.
What are the two types of specific immunity?
Immunity involves activation of specific lymphocytes that combat a particular pathogen or other foreign substance.
Specific resistance or immunity is ability to fight a specific pathogen. Two types of immunity:
– cell-mediated immunity
– antibody-mediated immunity
Lymphatic System Structure –
What is the name of the fluid that flows through the lymphatic system?
Lymph – very similar to interstitial fluid
Lymphatic System Structure –
Where are lymphocytes produced?
Bone Marrow
Lymphatic System Structure –
What are the main functions of the lymphatic system?
1) Draining excess interstitial fluid & plasma proteins from tissue spaces
2) Transporting dietary lipids &
vitamins from GI tract to the blood
3) Facilitating immune responses –recognize microbes or abnormal cells & responding by killing them directly or secreting antibodies that cause their destruction
Lymphatic System Structure –
Name the primary lymphatic organs.
Primary lymphatic organs
– provide environment for stem cells to divide & mature into B and T lymphocytes
• red bone marrow gives rise to mature B cells
• thymus is site where pre-T cells from red marrow mature
Lymphatic System Structure –
Name the secondary lymphatic organs.
Secondary lymphatic organs & tissues
– site where most immune responses occur
• lymph nodes, spleen & lymphatic nodules
Lymphatic System Structure –
Describe the differences between lymphatic vessels and blood vessels.
Lymphatic capillaries have a slightly larger diameter than blood capillaries and have overlapping endothelial cells which work as one-way valves for fluid to enter the lymphatic
capillary.
Lymphatic System Structure –
What are lacteals and where are they located?
A lymphatic capillary in the villus of the small intestine is the lacteal. It functions to transport digested fats from the small intestine into blood.
Lymph Ducts –
What are the names of the two major lymphatic ducts and what parts of the body do they drain?
the right lymphatic duct and the thoracic duct.
The thoracic duct receives lymph from the left side of the head, neck, and chest, the left upper extremity, and the entire body below the ribs.
• It drains lymph into venous blood via the left subclavian vein.
• The Right side head, arm & chest empty into right lymphatic
duct and rest of body empties into thoracic duct
• Lymph is dumped directly into left & right subclavian veins.
Thymus Gland –
Where in the body is the thymus gland located?
2 lobed organ located in mediastinum (superior and anterior to the heart)
Thymus Gland –
What cells are found in the thymic cortex?
tightly packed T lymphocytes & macrophages
Thymus Gland –
What cells are found in the thymic medulla?
– reticular epithelial cells produces thymic hormones
– Hassall’s corpuscles (possible sites of T cell death)
Thymus Gland –
What are Hassall’s corpuscles?
possible sites of T cell death
Thymus Gland –
What is the major function of the thymus?
thymus is site where pre-T cells from red marrow mature
Thymus Gland –
What is the difference in thymus size and function in the newborn compared to an adult?
Large organ in infants (70 g) but atrophied as adult (3 g).
Lymph Nodes –
Describe the structure and function of lymph nodes.
Lymph nodes are encapsulated oval structures located along lymphatic vessels.
- They contain some T cells, macrophages, follicular dendritic cells, and B cells.
- Lymph enters nodes through afferent lymphatic vessels, is filtered to remove damaged cells and microorganisms, and exits through efferent lymphatic vessels.
- Foreign substances filtered by the lymph nodes are trapped by nodal reticular fibers.
- Macrophages then destroy some foreign substances by phagocytosis and lymphocytes bring about the destruction of others by immune responses.
- Lymph nodes are the site of proliferation of plasma cells (mature B cells) and T cells.
Spleen –
What is found in the white pulp?
What is found in the red pulp?
Parenchyma consists of white pulp and red pulp:
– white is lymphatic tissue (lymphocytes & macrophages) around branches of splenic artery
– red pulp is venous sinuses filled with blood & splenic tissue (splenic cords)
Spleen –
What role does the spleen play in pregnancy that is does not usually perform?
TBD
Spleen –
What are trabeculae?
TBD
Lymphatic nodules –
Describe where MALT is found.
Where are the tonsils?
Where is the appendix?
TBD
Malignant Tumors –
What does the term metastasis mean? How does a tumor metastasize? What is the difference between a primary and secondary tumor?
TBD