The cellular immunity is derived from?

Appeared in: UPRVUNL - 2021

Explanation

Cellular immunity is a type of adaptive immunity mediated by T-lymphocytes (T-cells).
T-lymphocytes originate from stem cells in the bone marrow but migrate to the thymus gland to mature.
The maturation process in the thymus is what makes them 'Thymus-derived lymphocytes' and equips them to carry out cell-mediated functions.
These functions include directly killing infected cells (cytotoxic T-cells) and activating other immune cells (helper T-cells).

Option B: Red Blood Cells (RBCs) are responsible for oxygen transport and have no role in adaptive immunity.
Option C: Platelets are cell fragments involved in hemostasis (blood clotting), not in the specific recognition and destruction of pathogens that defines cellular immunity.
Option D: Bone marrow-derived lymphocytes refer to B-cells, which are responsible for humoral immunity (producing antibodies), not cellular immunity.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Origin and function of lymphocytes in cellular immunity as background academic context rather than a clinical decision trigger.
Understanding the origin of cellular immunity is fundamental for nurses, as it is the primary defense against viruses, fungi, and cancer cells.
Nurses monitor for signs of opportunistic infections in patients with compromised T-cell function, such as those with HIV/AIDS or undergoing chemotherapy, as their cellular immunity is weakened.
In organ transplantation, cellular immunity (specifically T-cells) is responsible for graft rejection. Immunosuppressive drugs given to transplant patients primarily target and suppress T-cell activity.

How to Approach the Question

First, identify the key term in the question: 'cellular immunity'.
Recall the two main types of adaptive immunity: cellular and humoral.
Associate 'cellular immunity' with T-lymphocytes (T-cells).
Remember the mnemonic: 'T' for 'Thymus'. T-cells mature in the thymus gland.
Evaluate the options: 'Thymus-derived lymphocytes' directly matches the definition of T-cells. 'Bone marrow-derived lymphocytes' refers to B-cells (humoral immunity). RBCs and platelets are not involved in adaptive immunity. This confirms the correct choice.

Concept Tested & Keywords

QU8pBOQJ1wS1eD99Turc0E

E6 Physiology Ganong 27e Vol 1 Part 1 p. 82-84

E6 Biochemistry U Satyanarayana— Part 2 (pp 421-820 of 840) p. 346-348

E6 Physiology Essentials Sembulingam 10e Part 1 p. 119-121

Practise the full UPRVUNL - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.