Page 463 - Atlas of Histology with Functional Correlations

Site where immature lymphocytes from the bone marrow mature into T cells,

helper T cells, and cytotoxic T cells
Thymic nurse cells promote lymphocyte differentiation, proliferation, and
maturation
Blood–thymus barrier prevents developing lymphocytes contacting blood-
borne antigens

Sends mature T cells to populate the lymph nodes, the spleen, and the
lymphatic tissues
Epithelial reticular cells secrete numerous hormones needed for lymphocyte

maturation
Epithelial reticular cells form thymic (Hassall) corpuscles in the medulla
Maturation of T cells involves positive and negative selection
Involutes and becomes filled with adipose tissues as the individual ages
Removal early in life results in loss of immunologic competence

Review Questions

QUESTIONS

In the following multiple-choice questions, choose the letter corresponding to the
one best answer.

1. The positive selection of lymphocytes in the thymus gland means that:

A. lymphocytes that recognize foreign antigens survive and reach
maturity.

B. lymphocytes that recognize self-antigens survive and reach maturity.

C. lymphocytes unable to recognize self-antigens are eliminated by
macrophages.

D. lymphocytes that recognize foreign antigens die.

E. lymphocytes are unable to recognize self-antigens.

2. The main function of red pulp in the spleen is to:

A. provide more lymphocytes for the system.

B. provide residence for B lymphocytes.

C. increase the presence of antigen-presenting cells.

D. provide new blood cells during blood loss.

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