Ch. 21: The Lymphatic System V1 P2

Covers immune cells and their jobs, lymphatic tissue, red bone marrow, and how T cells develop in the thymus.

What do neutrophils do in the lecture's lymphatic cell overview?

Fight bacteria

What do natural killer cells attack?

virus-infected cells, cancer cells, transplanted tissue

Where do T cells mature?

Thymus

What do activated B cells become?

Plasma cells

What do plasma cells produce?

Antibodies

What are macrophages derived from?

Monocytes

What are two roles of macrophages?

Phagocytosis, antigen presentation

What are dendritic cells?

Mobile, branched antigen-presenting cells

What do reticular cells form?

Stroma

What is lymphatic tissue?

Collections of lymphocytes in connective tissue

What is diffuse lymphatic tissue?

Scattered lymphocytes (MALT)

Which body systems have mucous membranes associated with MALT?

Digestive, respiratory, urinary, reproductive

What is a lymphatic nodule or follicle?

Dense mass of lymphocytes

Where are lymphatic nodules found?

Nodes, tonsils, appendix, small intestine

What are the primary lymphatic organs?

Red bone marrow, thymus

What does immunocompetent mean?

Able to recognize and respond to foreign antigens

What are the secondary lymphatic organs named in the lecture?

Lymph nodes, tonsils, spleen

What happens in secondary lymphatic organs?

Immune cells respond to antigens

What are the two broad roles of red bone marrow?

Blood formation, immunity

How is red bone marrow described structurally?

Loose, highly vascular tissue inside bone

How do developing blood cells enter the circulation from marrow?

Through marrow sinusoids into blood

Which marrow cell produces platelets?

Megakaryocyte

Where is the thymus located and what is its shape?

Superior mediastinum, bilobed

What is thymic involution?

Thymus shrinks with age

What are the two regions of each thymic lobule?

Outer cortex, inner medulla

How do developing T lymphocytes move through the thymus?

Cortex to medulla

Which signaling molecules does the lecture name in T-cell development?

Thymosin, thymopoietin, thymulin, interleukins, interferons