AP II LYMPHATIC SYSTEM
PRACTICE EXAM
Question 1: Which statement best describes a major homeostatic role of the
lymphatic system?
Choices:
1) It returns excess interstitial �uid and leaked plasma proteins to the bloodstream 2) It pumps oxygenated blood from the lungs to the tissues 3) It produces bile for fat digestion 4) It directly regulates glomerular �ltration rate Correct Answer: It returns excess interstitial �uid and leaked plasma proteins to the bloodstream Explanation: Lymphatic vessels collect excess interstitial �uid and escaped plasma proteins and return them to the venous circulation, helping maintain blood volume and tissue-�uid balance.Page 1
Question 2: Once interstitial �uid enters a lymphatic capillary, what is it called?
Choices:
1) Plasma 2) Lymph 3) Chyle 4) Serum
Correct Answer: Lymph
Explanation: Interstitial �uid is termed lymph after it enters lymphatic capillaries.Question 3: What structural feature of lymphatic capillaries most directly permits uptake of relatively large particles and proteins?
Choices:
1) A continuous basement membrane with tight junctions 2) Overlapping endothelial cells that act as one-way minivalves 3) A thick tunica media with smooth muscle 4) Fenestrations controlled by precapillary sphincters
Correct Answer: Overlapping endothelial cells that act as one-way minivalves
Explanation: Lymphatic capillary endothelial cells overlap loosely, forming �aplike minivalves that open when interstitial pressure rises and allow �uid, proteins, and particles to enter.Page 2
Question 4: Which structure anchors lymphatic capillary endothelial cells to
surrounding connective tissue and helps keep the minivalves open when tissue pressure rises?
Choices:
1) Elastic lamellae 2) Anchoring �laments 3) Chordae tendineae 4) Trabeculae
Correct Answer: Anchoring �laments
Explanation: Anchoring �laments attach lymphatic capillary endothelial cells to surrounding tissue. Tissue swelling pulls on these �laments and helps open the endothelial �aps.
Question 5: A patient has impaired lymph drainage from one lower limb. Which
change is most likely in the a�ected tissues?
Choices:
1) Decreased interstitial protein concentration 2) Accumulation of protein-rich interstitial �uid 3) Increased arterial oxygen content 4) Immediate fall in plasma glucose
Correct Answer: Accumulation of protein-rich interstitial �uid
Explanation: Obstructed lymph �ow prevents removal of excess interstitial �uid and proteins, producing protein-rich edema called lymphedema.Page 3