CH 20 Flashcards
What is the protein-containing fluid within lymphatic vessels?
Lymph
Lymph is the protein-containing fluid in lymphatic vessels.
Which organ stores blood platelets?
Spleen
The spleen stores blood platelets.
Which structure receives lymph from most of the body?
Thoracic duct
The thoracic duct drains lymph from most of the body.
What are small organs intimately associated with lymphatic vessels?
Lymph nodes
Lymph nodes are small organs linked to lymphatic vessels.
What is the largest lymphatic organ?
Spleen
The spleen is the largest lymphatic organ.
What are isolated clusters of lymph follicles found in the wall of the small intestines called?
Peyer’s patches
Peyer’s patches are lymphoid clusters in the small intestine.
Are Peyer’s patches clusters of lymphoid tissue found primarily in the large intestine?
FALSE
Peyer’s patches are in the small intestine, not the large intestine.
Do lymphatic capillaries function to absorb excess protein-containing interstitial fluid and return it to the bloodstream?
TRUE
Lymphatic capillaries absorb interstitial fluid.
Is lymph capillary permeability due to minivalves and protein filaments?
TRUE
Minivalves and filaments enable permeability.
Are lymphatic capillaries permeable to proteins?
TRUE
Proteins can enter lymphatic capillaries.
Are digested fats absorbed from the intestine by the lymph capillaries?
TRUE
Lacteals (lymph capillaries) absorb fats.
Is chyle delivered to the blood via the lymphatic system?
TRUE
Chyle (fat-rich lymph) enters blood via lymphatics.
Are there more efferent lymphatic vessels leaving a lymph node than there are afferent vessels entering?
FALSE
Fewer efferent vessels exist to slow lymph flow.
Is about 3 liters of fluid lost to the tissue spaces every 24 hours and returned to the bloodstream as lymph?
TRUE
3 liters/day is the approximate lymph volume.
Do movements of adjacent tissues help propel lymph through the lymphatics?
TRUE
Skeletal muscle contractions aid lymph flow.
Is lymphoid tissue mainly reticular connective tissue?
TRUE
Reticular connective tissue supports lymphoid organs.
Do lymphocytes reside temporarily in lymphoid tissue, then move to other parts of the body?
TRUE
Lymphocytes recirculate between lymphoid and non-lymphoid tissues.
Is the thymus the only lymphoid organ that does not directly fight antigens?
TRUE
The thymus matures T cells but does not filter antigens.
Does lymph flow both to and from the heart?
FALSE
Lymph flows one-way toward the heart.
When tissues are inflamed, do lymphatic capillaries permit uptake of large particles such as cell debris, pathogens, and cancer cells?
TRUE
Inflammation increases capillary permeability.
Does the cisterna chyli collect lymph from the lumbar trunks draining the upper limbs?
FALSE
Cisterna chyli drains lower limbs and intestines, not upper limbs.
If even a small part of the spleen is left in a ten-year-old child, will it most likely regenerate itself?
TRUE
Spleen tissue can regenerate.
In the spleen, is red pulp involved in immune functions and white pulp involved in disposing of worn-out RBCs?
FALSE
Roles are reversed: red pulp recycles RBCs; white pulp handles immunity.
Is the most important role of the spleen to provide a site for lymphocyte proliferation and immune surveillance and response?
FALSE
The spleen’s primary role is filtering blood, not lymphocyte proliferation.
Are lymph nodes the most important of the secondary lymphoid organs in the body?
TRUE
Lymph nodes are critical secondary lymphoid organs.
What are small secondary lymphoid organs that cluster along lymphatic vessels called?
Lymph nodes
Lymph nodes are small, bean-shaped secondary lymphoid organs that cluster along lymphatic vessels to filter lymph.
Which of the following would NOT be classified as a lymphoid organ?
Pancreas
The pancreas is a digestive and endocrine organ, not involved in lymphoid functions.
Which statement regarding the thymus is FALSE?
It has follicles similar to those in the spleen.
The thymus lacks follicles; these are found in lymph nodes and the spleen.
Which correctly describes the pathway of lymph?
Lymphatic capillaries to lymphatic vessels to lymphatic trunks to lymphatic ducts.
Lymph flows from capillaries to vessels, then trunks, and finally ducts.
When is the thymus most active?
Childhood
The thymus is most active in childhood, producing T cells, and atrophies after puberty.
Lymph traveling from the left arm would enter the venous circulation via which duct?
Thoracic duct
The thoracic duct drains lymph from the lower body and left upper limb.
Which of the following is NOT a part of the lymphatic system?
Erythrocytes
Erythrocytes are part of the blood, not the lymphatic system.
How do lymphatic capillaries compare to blood capillaries in terms of permeability?
More permeable than blood capillaries.
Lymphatic capillaries have minivalves and overlapping endothelial cells, enhancing permeability.
Antibodies that act against a particular foreign substance are released by which cells?
Plasma cells
Plasma cells are differentiated B cells that secrete antibodies.
How does lymph leave a lymph node?
Via efferent lymphatic vessels.
Efferent vessels drain lymph out of the node; fewer efferent vessels slow lymph flow.
What do lymph vessels NOT transport?
Erythrocytes
Erythrocytes remain in blood vessels and are not transported in lymph.
Which of the following functions of the spleen is NOT included?
Forming crypts that trap bacteria.
Crypts are found in tonsils, not the spleen.
What is the result when the lymphatic structures of a limb are blocked due to tumors?
Severe localized edema distal to the blockage of that limb.
Blockage prevents lymph drainage, causing fluid accumulation (edema).
Which statement about lymph transport is correct?
Lymph transport depends on the movement of adjacent tissues, such as skeletal muscles.
Skeletal muscle contractions and breathing aid lymph flow.
Which statement about lymphocytes is correct?
B cells produce plasma cells, which secrete antibodies into the blood.
Activated B cells differentiate into antibody-secreting plasma cells.
Which statement about lymphoid tissue is correct?
Lymphoid tissue is predominantly reticular connective tissue.
Reticular connective tissue forms the stroma of lymphoid organs.
What is lymphoid tissue that appears as a swelling of the mucosa in the oral cavity called?
Tonsil
Tonsils are mucosa-associated lymphoid tissue in the oral cavity.
Which of the following structures is NOT considered mucosa-associated lymphoid tissue (MALT)?
Thymus
The thymus is a primary lymphoid organ, not MALT.
Where are Peyer’s patches found?
In the distal portion of the small intestine.
Peyer’s patches are aggregated lymphoid nodules in the ileum.
Where are lymphatic capillaries present?
Digestive organs
Lymphatic capillaries are absent in bones, teeth, CNS, and bone marrow.
What is a bubo?
An infected lymph node.
A bubo is a swollen, infected lymph node, often in the groin or armpit.
What is the only lymphoid organ that does NOT directly fight antigens?
Thymus
The thymus matures T cells but does not directly combat pathogens.
Large clusters of lymph nodes are NOT found in which region?
Popliteal
Major clusters occur in cervical, axillary, and inguinal regions.
Which of the following is NOT a mucosa-associated lymphoid tissue?
Islets of Langerhans
Islets of Langerhans are pancreatic endocrine cells, not lymphoid tissue.
What maintains lymph flow?
Skeletal muscle contraction, breathing, and valves in lymph vessel walls.
Lymph flow relies on skeletal muscles, breathing, and valves, not capillary smooth muscle.
What are the tonsils located at the base of the tongue called?
Lingual tonsils
Lingual tonsils are at the base of the tongue.
Which lymphoid organs and tissues are characterized by a cortex and medulla?
Lymph nodes and thymus only.
Only lymph nodes and the thymus have distinct cortex and medulla regions.
Which lymphoid organ atrophies as we age?
Thymus
The thymus atrophies after puberty, reducing T cell production.
Which of the following is considered a primary lymphoid organ?
Thymus
Primary lymphoid organs include the thymus and bone marrow.
Which lymphoid organ atrophies as we age?
B) thymus
The thymus atrophies after puberty, reducing T cell production.
Which of the following is considered a primary lymphoid organ?
A) thymus
Primary lymphoid organs include the thymus and bone marrow.
Which of the following is NOT a function of the lymphatic system?
B) transporting respiratory gases
Respiratory gas transport is handled by the circulatory system.
Which of the following is NOT a function of the spleen?
D) produce new erythrocytes in adults
Erythrocyte production occurs in bone marrow, not the spleen (except in fetuses).
The blood testis barrier is to newly formed sperm cells as the blood thymus barrier is to ______.
C) T lymphocyte precursors
The blood-thymus barrier protects developing T cells from antigens.
Which of the following statements is FALSE?
C) Only lymph nodes filter lymph.
The spleen also filters blood, not lymph.
Which of the following statements is FALSE regarding the spleen?
D) Red pulp is where immune functions take place.
White pulp handles immune functions; red pulp filters blood.
Flow of lymph through a lymph node is slowed due to ______.
C) fewer efferent vessels draining it compared to many afferent vessels feeding it
Fewer efferent vessels cause lymph to stagnate, allowing immune cell activity.
Tonsils have blind-ended structures called ______ that trap bacteria and particulate matter.
C) tonsillar crypts
Crypts trap debris, which is then attacked by immune cells.
From the right leg, lymph moves in which order?
D) right lumbar trunk, thoracic duct, left subclavian vein
Lymph from the lower body drains into the thoracic duct.
Although B and T lymphocytes originate in the bone marrow, T cells mature in the ______.
A) thymus
T cells migrate to the thymus for maturation.
Lymphatic ______ are formed from the union of the largest collecting lymphatic vessels.
A) trunks
Trunks are formed by merging collecting vessels.
Fats absorbed from the small intestine are transported to the bloodstream via ______.
C) lacteals
Lacteals are specialized lymphatic capillaries in the small intestine.
Which lymphoid organ or tissue lacks a reticular fiber stroma?
D) thymus
The thymus has epithelial cells, not reticular fibers, in its stroma.
Describe the structural and functional relationship between a capillary bed of the blood vascular system and lymphatic capillaries.
Blind-ended lymphatic capillaries weave between the tissue cells and blood capillaries in the loose connective tissues of the body. Although similar to blood capillaries, lymphatic capillaries are even more permeable due to minivalves that act as one-way swinging doors. Leaked fluid from blood capillaries is taken up by the lymphatic capillaries as well as proteins in the interstitial space that are unable to enter blood capillaries.
Lymphatic capillaries absorb interstitial fluid and proteins due to their unique, permeable structure.
Describe the mechanisms by which lymphatic fluid is moved through the lymphatics.
Lymphatic fluid is moved through the lymphatics by the milking action of active skeletal muscles, pressure changes within the thorax during breathing, valves to prevent backflow, and pulsation of adjacent arteries.
Muscle contractions, respiratory movements, and vessel valves work together to propel lymph.
What is the consequence of obstruction of the lymphatics?
Obstruction of the lymphatics results in edema distal in the body to the obstruction.
Blockage in lymph flow causes fluid buildup and swelling in affected regions.
Where are the lymph node aggregations most dense?
Lymph node aggregations are most dense near the body surface in the inguinal, axillary, and cervical regions of the body.
Lymph nodes concentrate near the skin to filter lymph from peripheral areas.
By secreting hormones, the thymus gland causes T lymphocytes to become immunocompetent.
By secreting hormones, the thymus gland causes T lymphocytes to become immunocompetent.
The thymus produces hormones essential for T cell maturation.
Describe the anatomical locations of the tonsils.
Palatine tonsils are located on either side at the posterior end of the oral cavity. The lingual tonsil lies at the base of the tongue. The pharyngeal tonsil is in the posterior wall of the nasopharynx. The tiny tubal tonsils surround the openings of the auditory tubes into the pharynx.
This answer lists the precise anatomical locations of the tonsils.
List the functions of the spleen.
The spleen’s main functions are to remove aged or defective blood cells and platelets from the blood and to store or release some of the breakdown products of RBCs to the blood for processing by the liver. Other functions include acting as a blood filter and reservoir, serving as a site for erythrocyte production in developing embryos, storing blood platelets, and providing a site for lymphocyte proliferation and immune surveillance and response.
The spleen filters blood, recycles cells, and supports immune responses.
Characterize lymph transport in terms of rate, volume, and ability to change.
Lymph transport is sporadic and much slower than that occurring in veins. About 3 liters of lymph enters the bloodstream in a 24-hour period. An increase in physical activity will cause lymph flow to increase, balancing the greater rate of fluid outflow from the vascular system.
Lymph flow is slow but can increase with physical activity to maintain fluid balance.
How do the lymphatic capillaries differ from blood capillaries?
Although similar to blood capillaries, lymphatic capillaries differ structurally in the following ways: (1) The endothelial cells forming the walls of lymphatic capillaries are not tightly joined. Their edges loosely overlap one another, forming flaplike minivalves. (2) Bundles of fine filaments anchor the endothelial cells to surrounding structures so that any increase in interstitial fluid volume separates the cell flaps, exposing gaps in the wall rather than causing the lymphatic capillary to collapse.
Their overlapping, loosely connected cells and anchoring filaments allow efficient fluid uptake.
How does the lymphatic system both help and hinder the spread of cancer through the body?
Lymph nodes help rid the body of cancer cells by immune mechanisms. Lymph vessels may also be used to spread cancer cells throughout the body if immunity is not effective against the cancer cells because a cancer cell that escapes lymphatic filtration will reach the bloodstream and be carried anywhere in the body.
While lymph nodes filter cancer cells, escaped cells can disseminate via the lymphatic system.
How does the structure of a lymph node allow lymphocytes and macrophages to perform their protective function?
Macrophages and lymphocytes are located in lymph nodes. Macrophages ingest microorganisms and cellular debris. Lymphocytes monitor the lymphatic stream for the presence of antigens and mount an immune response. Because there are fewer efferent vessels draining the node than afferent vessels that feed it, the flow of lymph through the node stagnates somewhat, allowing time for the lymphocytes and macrophages to work.
The slow lymph flow in nodes provides time for immune cells to identify and neutralize pathogens.
Define the term MALT. What is its function?
MALT is an acronym for mucosa-associated lymphoid tissues. It includes Peyer’s patches, the appendix, and the tonsils in the digestive tract, lymphoid follicles in the walls of the bronchi, and genitourinary tract. Collectively, MALT protects passages open to the exterior from foreign matter invading the walls.
MALT comprises lymphoid tissues in mucosal areas that defend against invading pathogens.
How are lymphatic capillaries affected by tissue inflammation?
When tissues become inflamed, lymphatic capillaries develop openings that permit uptake of larger particles such as cell debris, pathogens (disease-causing microorganisms such as bacteria and viruses), and cancer cells. In the lymph nodes, cells of the immune system “examine” the lymph and cleanse it of debris.
Inflammation increases capillary permeability, allowing larger substances to enter the lymphatic system.
What is the significance of swollen and sore lymph glands?
When tissues are inflamed, such as due to a bacterial infection, lymphatic capillaries develop openings that permit the uptake of the pathogens. The inflammation and pain indicate lymph nodes infected by microorganisms.
Swollen, tender lymph nodes indicate an active immune response to infection.
What risks does a woman face after a mastectomy that included the removal of axillary lymph nodes?
Total removal of the axillary lymph nodes results in severe localized edema because the lymphatic vessels are also lost. This results in chronic edema along the arm, although some lymphatic drainage is eventually reestablished by regrowth of the vessels.
Lymph node removal can block lymph drainage, leading to arm swelling (lymphedema).
What is the treatment of choice for a ruptured spleen and the likely long-term outcome?
Supportive care or splenic repair is the treatment of choice, depending on severity. Splenectomy is not as necessary as once believed, and is now performed less frequently. If the spleen does need to be removed, the prognosis is very good, as the functions of the spleen are largely taken over by the liver and bone marrow.
Treatment aims to preserve splenic function; even without the spleen, compensatory mechanisms exist.
What could cause the increased size of a swollen leg?
The man has Filariasis commonly known as elephantiasis, which is caused by parasitic worms that get in the lymph system and reproduce to proportions that block the vessels. The swelling is due to edema.
Filariasis blocks lymphatic drainage, leading to severe swelling (elephantiasis).
What happens if lymphatics are obstructed?
Anything that prevents the normal return of lymph to the blood, such as blockage of the lymphatics by tumors or removal of lymphatics during surgery, results in severe localized edema (lymphedema).
Obstructions in lymph flow cause fluid accumulation and subsequent edema.
What do tender nodes indicate?
Tender nodes are usually due to inflammation, whereas hard, fixed, nontender nodes are suggestive of malignancy.
Painful nodes typically indicate infection; firm, immobile nodes may signal cancer.
How can cancer cells metastasize via the lymph system?
Cancer cells that break free from the primary tumor can metastasize via the lymph system. Even if a lymph node is 99% effective in trapping malignant cells, given the ability of a tumor to continuously shed cells into lymphatic capillaries, that still means that 100 out of every 10,000 cells get through. So the presence of any trapped cells in a lymph node is a warning that a few others may have escaped entrapment.
Even efficient lymphatic filtration may miss some cancer cells, indicating possible metastasis.
What can cause persistent swelling of lymph nodes?
This may occur because lymph nodes are overwhelmed by a large number of virus particles trapped in the nodes, which stimulate an ineffective immune reaction but cannot be quickly eliminated due to the weakened immune state. The weak immune reaction persists, causing swelling of the nodes.
An overburdened immune response in lymph nodes leads to persistent swelling.
