LYMPHATIC SYSTEM

LYMPHATIC SYSTEM

which is a subset of the circulatory system

Its functions are:the removal of interstitial fluidthe extracellular fluid that bathes most tissue

acts as a highway, transporting white blood cells to and from the lymph nodes into the bones, and antigen-presenting cells to the lymph nodes.

WHITE BLOOD CELLS (LEUKOCYTES)Main Categories:

1. Granulocytes2. Agranulocytes

Granulocytes includes: Neutrophils Eosinophils Basophils

Agranulocytes includes: Lymphocytes Monocytes Macrophages

Leukocytes With granulesThese granules are membrane-bound enzymes that act primarily in the digestion of endocytozed particles.

Granulocytes (polymorphonuclear leukocytes)

Microscopic Appreance Diagram

NEUTROPHILS Defend against bacterial or fungal infection and other very small inflammatory processes.

They are usually the first responders to microbial infection; their activity and death in large numbers forms pus.

EOSINOPHILS Primarily deal with parasitic infections

Modulate allergic inflammatory responses

Microscopic Appearance Diagram

BASOPHILSChiefly responsible for allergic and antigen response by releasing the chemical histamine, which causes dilation of the blood vessels.

Microscopic Appearence Diagram

LYMPHOCYTES come in three types:B-lymphocytesT-lymphocytesnatural killer cells

Microscopic Appearance Diagram

T-CELLS produce cytokine proteins which are

interpreted by phagocytes as commands to destroy the material that they have taken up

act against tumor cells and cells infected with viruses.

mature in thymus

B-CELLS produce antibodies that help phagocytes to

recognize foreign material.Located in the lymph nodes

NOTE: Both are produced by the bone marrow but mature in different places.

NATURAL KILLER cells a type of cytotoxic (cell toxic) lymphocyte

that represent a major component of the innate immune system.

reject tumors and cells infected by viruses. 

They work through the process of apoptosis or programmed cell death. They were termed “natural killers” because they do not require activation in order to kill cells.

MONOCYTES - present pieces of pathogens to T cells so that the pathogens may be recognized again and killed, or so that an antibody response may be mounted.

Microscopic AppearanceDiagram

MACROPHAGES are monocytes that have migrated out of the blood stream and into the body tissues. They take up and destroy necrotic cell debris and foreign material including viruses, bacteria, and tattoo ink