Lymphatic System: Immunity, Lymphocytes, and Lymph Nodes

4 functions of lymphatic system

1)Transport lipids and lipid-soluble vitamins

2)Return interstitial fluids to blood

3)Produce and maintain lymphocytes

4)Respond to antigens with immune response

lymphatic vessels

smallest vessels, accepts interstitial fluids, one-way openings, valves stop backflow of lymph (low pressure)

pathway of lymph

Lymph travels to ducts, two ducts right lymphatic duct and thoracic duct, drain into subclavian veins into blood

what cells cause an inflammatory response to injury?

mast cells and macrophages

What do macrophages release?

cytokines

What do mast cells release?

histamine

antigen-presenting cells

dendritic cells

what are the 3 categories of lymphocytes

1) cell-mediated immunity or T cells

2) antibody-mediated immunity or humoral immunity

3) NK or natural killer cells

Helper T cells

unique to antigen, secret cytokine, stimulate B cells and cytotoxic T cells (trigger apoptosis)

What do memory T cells do?

recognize same antigen later

What are the 2 T cells that fall under cell-mediated immunity or T cells?

Helper T cells and Memory T cells

What are the 2 cells that fall under antibody-mediated immunity or humoral immunity?

Plasmocytes and memory B cells

What do plasmocytes do?

make antibodies (neutralize and cause to be destroyed)

What do memory B cells do?

respond if antigen reappears

What do NK or natural killer cells do?

responds to muliptle antigens, infected cells, foreign cells and some cancer cells too, forces apoptosis

where do T cells mature?

in the thymus

where do NK and B cells mature?

in bone marrow

where are lymph nodes found?

along vessels

what do lymph nodes contain?

lymphocytes and macrophages

Where does metastasis typically occur?

typically occurs within the lymph nodes

Where are the 3 places where lymph nodes are found?

cervical, axillary and inguinal

what are the 2 different vessels in lymph nodes?

afferent and efferent vessels

how many afferent vessels are in lymph nodes and what do they carry?

4, unfiltered lymph fluid

how many efferent vessels are in lymph nodes and what do they carry?

1, filtered lymph fluid

What are tonsils?

nodules of lymphoid tissues (connective tissue with lymphocytes)

what are the 3 types of tonsils?

from top to bottom pharyngeal, palatine, and lingual

what are the lymphoid organs?

Thymus and spleen

what does the thymus do for the lymphatic system?

releases thymosins which are hormones for T lymphocyte maturation

Where is the thymus in the body?

below the thyroid gland and above the heart

What does the spleen do for the lymphatic system?

responds to antigens in blood with lymphocytes and filters old blood cells (recycles iron)