ANP1105 Final Exam 2026–2027 Exam
Questions and Verified Correct Answers
What specific structural adaptation allows lymphatic capillaries to absorb
interstitial fluid efficiently? - CORRECT ANSWER They have flap-like
minivalves formed by overlapping endothelial cells, which open when
interstitial pressure is high, allowing fluid and large molecules to enter.
How does the absence of a well-developed lymphatic system in the brain
(before the discovery of the glymphatic system) affect cerebrospinal fluid
(CSF) clearance? - CORRECT ANSWER CSF clearance was previously thought
to occur via bulk flow into venous sinuses, but the glymphatic system
(discovered recently) provides an active pathway for CSF and interstitial fluid
drainage via astrocyte channels.
How do lymph nodes structurally slow down lymph flow to maximize
immune function? - CORRECT ANSWER More afferent vessels than efferent
vessels create a bottleneck effect, allowing lymph to stagnate and
maximizing antigen detection by immune cells.
Why are there no lymphatic arteries, only lymphatic veins? - CORRECT
ANSWER Lymphatic circulation is one-way, relying on passive movement
mechanisms (muscle contractions, valves) rather than active pumping by the
heart.
Compare the antigen-presenting capabilities of dendritic cells, macrophages,
and B cells. - CORRECT ANSWER Dendritic cells are the most efficient at
antigen presentation and initiating T-cell responses, while macrophages
primarily function in phagocytosis and antigen presentation in secondary
,immune responses. B cells present antigens to helper T cells to trigger
antibody production.
How does lymph composition vary depending on its source in the body? -
CORRECT ANSWER Lymph from the small intestine (chyle) is rich in lipids,
while lymph from infected tissues may have a high white blood cell
concentration.
What is the significance of the thoracic duct passing through the diaphragm
at the aortic hiatus? - CORRECT ANSWER This anatomical positioning allows
the duct to efficiently collect lymph from the abdomen and lower limbs while
being protected from excessive compression.
What is the role of fibroblastic reticular cells in lymphoid organs? - CORRECT
ANSWER They form the stromal network of lymphoid tissues, produce
chemokines to guide immune cells, and help organize the architecture of
lymph nodes.
How does the spleen compensate for its loss following a splenectomy? -
CORRECT ANSWER The liver and bone marrow take over its functions,
particularly the removal of aged red blood cells and immune surveillance.
However, there is an increased risk of infections from encapsulated bacteria
(e.g., Streptococcus pneumoniae).
What is the difference between central tolerance and peripheral tolerance in
the immune system? - CORRECT ANSWER Central tolerance occurs in primary
lymphoid organs (thymus, bone marrow) and eliminates self-reactive T and B
cells. Peripheral tolerance occurs in secondary lymphoid organs and prevents
autoimmunity through regulatory T cells and anergy.
,Why are Peyer's patches strategically located in the ileum? - CORRECT
ANSWER The ileum is close to the ileocecal junction, where microbial
exposure from the large intestine is high. Peyer's patches help monitor and
mount immune responses against gut pathogens.
What is the function of high endothelial venules (HEVs) in lymph nodes? -
CORRECT ANSWER HEVs allow naïve lymphocytes to exit the bloodstream
and enter the lymph node, facilitating immune surveillance.
How does lymphangiogenesis contribute to pathological conditions such as
cancer and chronic inflammation? - CORRECT ANSWER Excess lymphatic
vessel growth (lymphangiogenesis) can promote cancer metastasis and
contribute to tissue swelling in chronic inflammatory conditions like
rheumatoid arthritis.
How does the presence of M cells in Peyer's patches enhance immune
surveillance in the gut? - CORRECT ANSWER M cells transport antigens and
microbes from the intestinal lumen to underlying lymphoid tissue, initiating
immune responses.
How does the protein CCL19/CCL21 contribute to lymphocyte migration in
lymph nodes? - CORRECT ANSWER These chemokines attract T cells and
dendritic cells to the lymph node cortex, where antigen presentation occurs.
What is the role of the spleen's marginal zone in immune function? -
CORRECT ANSWER It serves as a transitional area where antigen-presenting
cells (APCs) capture blood-borne antigens and activate immune responses.
, How does lymphatic dysfunction contribute to elephantiasis? - CORRECT
ANSWER Parasitic infections (e.g., Wuchereria bancrofti) block lymphatic
drainage, causing severe lymphedema and tissue swelling.
What molecular mechanisms regulate lymphatic vessel permeability? -
CORRECT ANSWER VEGF-C and VEGF-D regulate lymphatic endothelial
permeability by modulating tight junction proteins.
What is the role of the Prox1 transcription factor in lymphatic development?
- CORRECT ANSWER Prox1 is the master regulator of lymphatic endothelial
cell differentiation, responsible for transforming venous endothelial cells into
lymphatic endothelial cells during embryogenesis.
How does the sodium-hydrogen exchanger (NHE1) influence lymphatic
contractility? - CORRECT ANSWER NHE1 regulates intracellular pH and ion
balance in lymphatic smooth muscle cells, affecting their rhythmic
contraction and overall lymphatic drainage.
Why does the thoracic duct drain into the left venous angle, rather than the
right? - CORRECT ANSWER The left venous angle receives the majority of the
body's lymph due to embryological asymmetry in venous and lymphatic
development, with the thoracic duct forming from the leftsided embryonic
lymph sac.
What role do aquaporins (AQPs) play in lymphatic vessel function? -
CORRECT ANSWER AQPs facilitate water transport across lymphatic
endothelial cells, affecting lymph volume regulation and permeability.
Questions and Verified Correct Answers
What specific structural adaptation allows lymphatic capillaries to absorb
interstitial fluid efficiently? - CORRECT ANSWER They have flap-like
minivalves formed by overlapping endothelial cells, which open when
interstitial pressure is high, allowing fluid and large molecules to enter.
How does the absence of a well-developed lymphatic system in the brain
(before the discovery of the glymphatic system) affect cerebrospinal fluid
(CSF) clearance? - CORRECT ANSWER CSF clearance was previously thought
to occur via bulk flow into venous sinuses, but the glymphatic system
(discovered recently) provides an active pathway for CSF and interstitial fluid
drainage via astrocyte channels.
How do lymph nodes structurally slow down lymph flow to maximize
immune function? - CORRECT ANSWER More afferent vessels than efferent
vessels create a bottleneck effect, allowing lymph to stagnate and
maximizing antigen detection by immune cells.
Why are there no lymphatic arteries, only lymphatic veins? - CORRECT
ANSWER Lymphatic circulation is one-way, relying on passive movement
mechanisms (muscle contractions, valves) rather than active pumping by the
heart.
Compare the antigen-presenting capabilities of dendritic cells, macrophages,
and B cells. - CORRECT ANSWER Dendritic cells are the most efficient at
antigen presentation and initiating T-cell responses, while macrophages
primarily function in phagocytosis and antigen presentation in secondary
,immune responses. B cells present antigens to helper T cells to trigger
antibody production.
How does lymph composition vary depending on its source in the body? -
CORRECT ANSWER Lymph from the small intestine (chyle) is rich in lipids,
while lymph from infected tissues may have a high white blood cell
concentration.
What is the significance of the thoracic duct passing through the diaphragm
at the aortic hiatus? - CORRECT ANSWER This anatomical positioning allows
the duct to efficiently collect lymph from the abdomen and lower limbs while
being protected from excessive compression.
What is the role of fibroblastic reticular cells in lymphoid organs? - CORRECT
ANSWER They form the stromal network of lymphoid tissues, produce
chemokines to guide immune cells, and help organize the architecture of
lymph nodes.
How does the spleen compensate for its loss following a splenectomy? -
CORRECT ANSWER The liver and bone marrow take over its functions,
particularly the removal of aged red blood cells and immune surveillance.
However, there is an increased risk of infections from encapsulated bacteria
(e.g., Streptococcus pneumoniae).
What is the difference between central tolerance and peripheral tolerance in
the immune system? - CORRECT ANSWER Central tolerance occurs in primary
lymphoid organs (thymus, bone marrow) and eliminates self-reactive T and B
cells. Peripheral tolerance occurs in secondary lymphoid organs and prevents
autoimmunity through regulatory T cells and anergy.
,Why are Peyer's patches strategically located in the ileum? - CORRECT
ANSWER The ileum is close to the ileocecal junction, where microbial
exposure from the large intestine is high. Peyer's patches help monitor and
mount immune responses against gut pathogens.
What is the function of high endothelial venules (HEVs) in lymph nodes? -
CORRECT ANSWER HEVs allow naïve lymphocytes to exit the bloodstream
and enter the lymph node, facilitating immune surveillance.
How does lymphangiogenesis contribute to pathological conditions such as
cancer and chronic inflammation? - CORRECT ANSWER Excess lymphatic
vessel growth (lymphangiogenesis) can promote cancer metastasis and
contribute to tissue swelling in chronic inflammatory conditions like
rheumatoid arthritis.
How does the presence of M cells in Peyer's patches enhance immune
surveillance in the gut? - CORRECT ANSWER M cells transport antigens and
microbes from the intestinal lumen to underlying lymphoid tissue, initiating
immune responses.
How does the protein CCL19/CCL21 contribute to lymphocyte migration in
lymph nodes? - CORRECT ANSWER These chemokines attract T cells and
dendritic cells to the lymph node cortex, where antigen presentation occurs.
What is the role of the spleen's marginal zone in immune function? -
CORRECT ANSWER It serves as a transitional area where antigen-presenting
cells (APCs) capture blood-borne antigens and activate immune responses.
, How does lymphatic dysfunction contribute to elephantiasis? - CORRECT
ANSWER Parasitic infections (e.g., Wuchereria bancrofti) block lymphatic
drainage, causing severe lymphedema and tissue swelling.
What molecular mechanisms regulate lymphatic vessel permeability? -
CORRECT ANSWER VEGF-C and VEGF-D regulate lymphatic endothelial
permeability by modulating tight junction proteins.
What is the role of the Prox1 transcription factor in lymphatic development?
- CORRECT ANSWER Prox1 is the master regulator of lymphatic endothelial
cell differentiation, responsible for transforming venous endothelial cells into
lymphatic endothelial cells during embryogenesis.
How does the sodium-hydrogen exchanger (NHE1) influence lymphatic
contractility? - CORRECT ANSWER NHE1 regulates intracellular pH and ion
balance in lymphatic smooth muscle cells, affecting their rhythmic
contraction and overall lymphatic drainage.
Why does the thoracic duct drain into the left venous angle, rather than the
right? - CORRECT ANSWER The left venous angle receives the majority of the
body's lymph due to embryological asymmetry in venous and lymphatic
development, with the thoracic duct forming from the leftsided embryonic
lymph sac.
What role do aquaporins (AQPs) play in lymphatic vessel function? -
CORRECT ANSWER AQPs facilitate water transport across lymphatic
endothelial cells, affecting lymph volume regulation and permeability.
