Review | 75 Practice Questions & Answers with
Explanations | Lymphatic System & Immunity | Portage
Learning LockDown Browser 2026 | pdf
Introduction
Prepare with confidence for the BIOL 252 Human Anatomy & Physiology II Module 4 Exam using this
comprehensive 75-question practice exam designed for Portage Learning students. Each multiple-
choice question includes the correct answer and a detailed explanation to reinforce key concepts,
strengthen critical thinking, and improve exam readiness for the LockDown Browser assessment.
This Module 4 review provides comprehensive coverage of the lymphatic and immune systems,
including lymphatic vessels, lymph formation and circulation, lymph nodes, spleen, thymus, tonsils, Peyer's
patches, red bone marrow, innate and adaptive immunity, B and T lymphocytes, natural killer cells,
antibodies and immunoglobulins (IgG, IgA, IgM, IgE, and IgD), antigen presentation, major
histocompatibility complex (MHC), complement pathways, cytokines, inflammation, fever, phagocytosis,
active and passive immunity, vaccinations, immunological memory, hypersensitivity reactions, autoimmune
diseases, immunodeficiency disorders, HIV/AIDS, organ transplantation, graft types, and immune system
homeostasis. This study guide is ideal for self-assessment, reinforcing course material, and preparing for
the BIOL 252 Module 4 Portage Learning LockDown Browser Exam in 2026.
Lymphatic System & Immunity
,Question 1
2. Which fluid occupies the spaces surrounding body cells before entering lymphatic
capillaries and becoming lymph?
A. Plasma
B. Cerebrospinal fluid
C. Synovial fluid
D. Interstitial fluid
Answer: D. Interstitial fluid
Interstitial fluid bathes body cells, delivering nutrients and removing waste products. Once it
enters lymphatic capillaries, it is referred to as lymph.
, 3. Which specialized lymphatic vessels have overlapping endothelial cells that allow
excess tissue fluid to enter while preventing its escape?
A. Arterioles
B. Venules
C. Elastic arteries
D. Lymphatic capillaries
Answer: D. Lymphatic capillaries
Lymphatic capillaries have unique flap-like endothelial cells that permit interstitial fluid,
proteins, and immune cells to enter while minimizing backflow.
4. Which structures within lymphatic vessels help ensure the one-way movement of
lymph toward the heart?
A. Smooth muscle sphincters
B. Cartilage rings
C. Papillary muscles
D. One-way valves
Answer: D. One-way valves
One-way valves prevent the backflow of lymph, allowing it to move toward the venous
circulation despite the absence of a central pumping organ.
5. Which mechanism contributes most directly to the movement of lymph through
lymphatic vessels during normal daily activities?
A. Cardiac muscle contractions only
B. Pulmonary surfactant production
C. Hormonal secretion from the thymus
D. Skeletal muscle contractions and respiratory movements
Answer: D. Skeletal muscle contractions and respiratory movements
Skeletal muscle activity, breathing movements, and smooth muscle contraction within
lymphatic vessels work together to propel lymph toward the heart.