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BIO 202L LAB 12 WORKSHEET LYMPHATIC SYSTEM
2026/2027 | Immunity & Lymphoid Organs |
Comprehensive Lab Assessment | Pass Guaranteed - A+
Graded
Section 1: Lymphatic Vessels & Lymph Circulation (Q1-12)
Q1. Which structural feature of lymphatic capillaries allows them to absorb large
proteins and fluid from interstitial space more readily than blood capillaries? A.
Continuous tight junctions between endothelial cells B. Overlapping endothelial cells
that function as one-way minivalves C. A complete basement membrane surrounding
the vessel D. Thick smooth muscle layers in the capillary wall
Answer: B. Overlapping endothelial cells that function as one-way minivalves
[CORRECT] Rationale: Lymphatic capillaries possess overlapping endothelial cells
anchored by filaments to surrounding connective tissue; these flaps open under
increased interstitial pressure to permit entry of fluid, proteins, and even cells, then
close to prevent backflow.
"Correct Answer: B"
Q2. A student examining a lymphatic collecting vessel under the microscope notes
the presence of bulging segments between valves. These contractile segments are
called: A. Lymphangions B. Arterioles C. Venous sinuses D. Capillary loops
Answer: A. Lymphangions [CORRECT] Rationale: Collecting lymphatic vessels contain
lymphangions—segments between bicuspid valves that possess smooth muscle
capable of intrinsic contraction (lymphatic pump), propelling lymph toward the ducts.
"Correct Answer: A"
Q3. During a laboratory exercise on fluid dynamics, a student observes that when
skeletal muscles surrounding a lymphatic vessel contract, lymph flow increases. This
,2
mechanism of lymph propulsion is best described as the: A. Respiratory pump B.
Skeletal muscle pump C. Cardiac suction effect D. Gravity-dependent drainage
Answer: B. Skeletal muscle pump [CORRECT] Rationale: Contraction of adjacent
skeletal muscles compresses lymphatic vessels; because valves prevent backflow, this
external compression propels lymph forward, analogous to venous return but critical
since lymphatics lack a central pump.
"Correct Answer: B"
Q4. Which lymphatic trunk drains lymph from the upper limb, breast, and superficial
thoracic wall on the left side of the body? A. Intestinal trunk B. Jugular trunk C.
Subclavian trunk D. Lumbar trunk
Answer: C. Subclavian trunk [CORRECT] Rationale: The subclavian trunk drains lymph
from the upper limbs, breasts, and superficial thoracic walls; paired left and right
subclavian trunks ultimately deliver lymph into the thoracic duct or right lymphatic
duct.
"Correct Answer: C"
Q5. A tracer injected into the interstitial fluid of the left foot is recovered in the
venous circulation. Which sequence correctly traces the pathway from interstitial
space to blood? A. Interstitial fluid → lymphatic capillary → collecting vessel →
lumbar trunk → cisterna chyli → thoracic duct → left subclavian vein B. Interstitial
fluid → lymphatic capillary → collecting vessel → lumbar trunk → right lymphatic duct
→ right subclavian vein C. Interstitial fluid → blood capillary → lymphatic capillary →
collecting vessel → thoracic duct → left subclavian vein D. Interstitial fluid →
lymphatic capillary → collecting vessel → bronchomediastinal trunk → right lymphatic
duct → left subclavian vein
Answer: A. Interstitial fluid → lymphatic capillary → collecting vessel → lumbar trunk
→ cisterna chyli → thoracic duct → left subclavian vein [CORRECT] Rationale: Lymph
from the left lower limb drains via lymphatic capillaries into collecting vessels, then
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through lumbar trunks into the cisterna chyli, ascending through the thoracic duct to
empty into the left subclavian vein at the venous angle.
"Correct Answer: A"
Q6. The right lymphatic duct receives lymph from which of the following lymphatic
trunks? A. Intestinal, lumbar, and bronchomediastinal trunks B. Jugular, subclavian,
and bronchomediastinal trunks C. Jugular, lumbar, and intestinal trunks D.
Subclavian, lumbar, and intestinal trunks
Answer: B. Jugular, subclavian, and bronchomediastinal trunks [CORRECT] Rationale:
The right lymphatic duct drains the right upper quadrant of the body—specifically
the right side of the head and neck (jugular), right upper limb (subclavian), and right
thorax (bronchomediastinal)—emptying into the right subclavian vein.
"Correct Answer: B"
Q7. A patient has sustained trauma to the thoracic duct at the level of T12. Which
body region would experience impaired lymphatic drainage? A. Right upper limb and
right side of head B. Entire body except the right upper quadrant C. Only the
abdominal organs D. Only the lower limbs
Answer: B. Entire body except the right upper quadrant [CORRECT] Rationale: The
thoracic duct originates at the cisterna chyli and ascends to drain lymph from all
body regions except the right upper quadrant (right side of head/neck, right upper
limb, right thorax), which is served by the right lymphatic duct.
"Correct Answer: B"
Q8. Following a fatty meal, chylomicrons are absorbed by specialized lymphatic
capillaries in the small intestine. These intestinal lymphatic capillaries are called: A.
Lacteals B. Peyer’s patches C. Lymphangions D. Cisterna chyli
BIO 202L LAB 12 WORKSHEET LYMPHATIC SYSTEM
2026/2027 | Immunity & Lymphoid Organs |
Comprehensive Lab Assessment | Pass Guaranteed - A+
Graded
Section 1: Lymphatic Vessels & Lymph Circulation (Q1-12)
Q1. Which structural feature of lymphatic capillaries allows them to absorb large
proteins and fluid from interstitial space more readily than blood capillaries? A.
Continuous tight junctions between endothelial cells B. Overlapping endothelial cells
that function as one-way minivalves C. A complete basement membrane surrounding
the vessel D. Thick smooth muscle layers in the capillary wall
Answer: B. Overlapping endothelial cells that function as one-way minivalves
[CORRECT] Rationale: Lymphatic capillaries possess overlapping endothelial cells
anchored by filaments to surrounding connective tissue; these flaps open under
increased interstitial pressure to permit entry of fluid, proteins, and even cells, then
close to prevent backflow.
"Correct Answer: B"
Q2. A student examining a lymphatic collecting vessel under the microscope notes
the presence of bulging segments between valves. These contractile segments are
called: A. Lymphangions B. Arterioles C. Venous sinuses D. Capillary loops
Answer: A. Lymphangions [CORRECT] Rationale: Collecting lymphatic vessels contain
lymphangions—segments between bicuspid valves that possess smooth muscle
capable of intrinsic contraction (lymphatic pump), propelling lymph toward the ducts.
"Correct Answer: A"
Q3. During a laboratory exercise on fluid dynamics, a student observes that when
skeletal muscles surrounding a lymphatic vessel contract, lymph flow increases. This
,2
mechanism of lymph propulsion is best described as the: A. Respiratory pump B.
Skeletal muscle pump C. Cardiac suction effect D. Gravity-dependent drainage
Answer: B. Skeletal muscle pump [CORRECT] Rationale: Contraction of adjacent
skeletal muscles compresses lymphatic vessels; because valves prevent backflow, this
external compression propels lymph forward, analogous to venous return but critical
since lymphatics lack a central pump.
"Correct Answer: B"
Q4. Which lymphatic trunk drains lymph from the upper limb, breast, and superficial
thoracic wall on the left side of the body? A. Intestinal trunk B. Jugular trunk C.
Subclavian trunk D. Lumbar trunk
Answer: C. Subclavian trunk [CORRECT] Rationale: The subclavian trunk drains lymph
from the upper limbs, breasts, and superficial thoracic walls; paired left and right
subclavian trunks ultimately deliver lymph into the thoracic duct or right lymphatic
duct.
"Correct Answer: C"
Q5. A tracer injected into the interstitial fluid of the left foot is recovered in the
venous circulation. Which sequence correctly traces the pathway from interstitial
space to blood? A. Interstitial fluid → lymphatic capillary → collecting vessel →
lumbar trunk → cisterna chyli → thoracic duct → left subclavian vein B. Interstitial
fluid → lymphatic capillary → collecting vessel → lumbar trunk → right lymphatic duct
→ right subclavian vein C. Interstitial fluid → blood capillary → lymphatic capillary →
collecting vessel → thoracic duct → left subclavian vein D. Interstitial fluid →
lymphatic capillary → collecting vessel → bronchomediastinal trunk → right lymphatic
duct → left subclavian vein
Answer: A. Interstitial fluid → lymphatic capillary → collecting vessel → lumbar trunk
→ cisterna chyli → thoracic duct → left subclavian vein [CORRECT] Rationale: Lymph
from the left lower limb drains via lymphatic capillaries into collecting vessels, then
, 3
through lumbar trunks into the cisterna chyli, ascending through the thoracic duct to
empty into the left subclavian vein at the venous angle.
"Correct Answer: A"
Q6. The right lymphatic duct receives lymph from which of the following lymphatic
trunks? A. Intestinal, lumbar, and bronchomediastinal trunks B. Jugular, subclavian,
and bronchomediastinal trunks C. Jugular, lumbar, and intestinal trunks D.
Subclavian, lumbar, and intestinal trunks
Answer: B. Jugular, subclavian, and bronchomediastinal trunks [CORRECT] Rationale:
The right lymphatic duct drains the right upper quadrant of the body—specifically
the right side of the head and neck (jugular), right upper limb (subclavian), and right
thorax (bronchomediastinal)—emptying into the right subclavian vein.
"Correct Answer: B"
Q7. A patient has sustained trauma to the thoracic duct at the level of T12. Which
body region would experience impaired lymphatic drainage? A. Right upper limb and
right side of head B. Entire body except the right upper quadrant C. Only the
abdominal organs D. Only the lower limbs
Answer: B. Entire body except the right upper quadrant [CORRECT] Rationale: The
thoracic duct originates at the cisterna chyli and ascends to drain lymph from all
body regions except the right upper quadrant (right side of head/neck, right upper
limb, right thorax), which is served by the right lymphatic duct.
"Correct Answer: B"
Q8. Following a fatty meal, chylomicrons are absorbed by specialized lymphatic
capillaries in the small intestine. These intestinal lymphatic capillaries are called: A.
Lacteals B. Peyer’s patches C. Lymphangions D. Cisterna chyli
