Physiology II w/Lab Q&A | Portage Learning
1. The primary function of the lymphatic system is to:
A) Return excess interstitial fluid to the blood
B) Transport oxygen to tissues
C) Produce red blood cells
D) Synthesize vitamin D
Correct Answer: A) Return excess interstitial fluid to the blood
Rationale: Lymphatic vessels collect fluid that leaks from capillaries and return it
to venous circulation, preventing edema and maintaining blood volume. Oxygen
transport is by erythrocytes; RBC production occurs in bone marrow; vitamin D
synthesis occurs in the skin.
2. Specialized lymphatic capillaries in the small intestine that absorb dietary
lipids are called:
A) Venules
B) Lacteals
C) Sinusoids
D) Peyer's patches
Correct Answer: B) Lacteals
Rationale: Lacteals are lymphatic capillaries within intestinal villi that absorb
chylomicrons containing long‑chain fatty acids and fat‑soluble vitamins,
,transporting them into the lymphatic system. Venules are blood vessels;
sinusoids are liver capillaries; Peyer's patches are lymphoid tissue.
3. Lymph flows in which correct order?
A) Capillaries → ducts → vessels → trunks
B) Vessels → capillaries → trunks → ducts
C) Capillaries → vessels → trunks → ducts
D) Trunks → vessels → capillaries → ducts
Correct Answer: C) Capillaries → vessels → trunks → ducts
Rationale: Lymphatic capillaries merge into larger vessels, then trunks (lumbar,
bronchomediastinal, etc.), and finally the thoracic and right lymphatic ducts,
which empty into venous circulation at the subclavian veins.
4. Monocytes that emigrate into tissues and differentiate into phagocytic cells
are called:
A) Neutrophils
B) Eosinophils
C) Lymphocytes
D) Macrophages
Correct Answer: D) Macrophages
Rationale: Monocytes leave the bloodstream and become macrophages, which
are potent phagocytes that engulf pathogens, debris, and present antigens.
, Neutrophils are also phagocytic but do not differentiate from monocytes;
eosinophils target parasites; lymphocytes mediate adaptive immunity.
5. Which white blood cell type releases histamine and heparin during allergic
reactions?
A) Neutrophil
B) Lymphocyte
C) Basophil
D) Monocyte
Correct Answer: C) Basophil
Rationale: Basophils contain granules rich in histamine (vasodilator) and heparin
(anticoagulant), which are released upon activation, promoting inflammation
and the allergic response. Neutrophils are phagocytic; lymphocytes are specific
immunity; monocytes become macrophages.
6. The right lymphatic duct drains lymph from the:
A) Entire body
B) Left upper quadrant
C) Lower limbs
D) Right upper quadrant
Correct Answer: D) Right upper quadrant