ATI RN
Lymphatic System Questions and Answers PDF Questions
Question 1 of 5
What is the problem with the short cytoplasmic tails of TCRs?
Correct Answer: B
Rationale: Short TCR tails can't signal activation ; CD3 compensates; antigen recognition and co-receptor binding are intact.
Question 2 of 5
The thoracic duct empties directly into the vein
Correct Answer: B
Rationale: The thoracic duct empties into the left subclavian vein at the jugular-subclavian junction.
Question 3 of 5
When complement proteins are covalently deposited onto the surface of a bacterium, this can sometimes lead to direct lysis of the bacterium. However, more commonly, the deposition of complement proteins onto the bacterial surface does not directly harm the bacterium. Instead, these complement proteins aid in bacterial elimination by:
Correct Answer: D
Rationale: Complement (e.g., C3b) enhances phagocytosis via complement receptors ; Fc receptors are antibody-related, not replication or B-cell stimulation .
Question 4 of 5
Innate lymphoid cells (ILCs) are effector cells that generally reside in barrier tissues, such as the skin, the gut, and the lung. These cells closely resemble subsets of T lymphocytes, but lack a T cell antigen-receptor. Instead, these cells produce their effector molecules following stimulation by:
Correct Answer: D
Rationale: ILCs respond to cytokines from innate cells ; PAMPs are indirect, TNF-α or acute phase proteins are less specific triggers.
Question 5 of 5
Scaffold proteins are often phosphorylated at multiple sites, allowing the recruitment of several different signaling proteins. In antigen receptor signaling pathways, this mechanism is used to bring enzymes in close proximity to their substrates. Termination of this signaling mechanism would be most efficiently accomplished by:
Correct Answer: D
Rationale: Dephosphorylation disrupts scaffold signaling; ubiquitination is slower, GAP or depletion are less direct.