DAT: Lymphatic System

Lymphatic System

• Network of vessels, nodes, and organs

• Moves lymph through the body via Muscle contraction

• Interstitial fluid

• Aid in monitoring the body for infection

• absorb large proteins and other particles that are too big for blood capillaries to take up directly

• Functions

  • Returns extra fluid, proteins, and particles to blood

  • Immune defense

interstitial fluid inside lymph vessels

Lymph

fluid between cells

Interstitial fluid

• bone marrow

• thymus

Primary (Central) Lymphoid Organs

• lymph nodes

• spleen

• adenoids (tonsils)

• appendix

• peyer’s patches

• responsible for housing immune cells, such as lymphocytes, and for filtering lymph and blood to detect pathogens

• they do NOT replenish immune cells

Secondary (Peripheral) Lymphoid Organs

• Makes all blood cells

• Origin of all immune cells

• Leukocytes = all WBCs

• Lymphocytes = B cells + T cells

Bone marrow

all WBCs

Leukocytes

• B cells+T cells

• originates directly from the bone marrow and supports the immune response

Lymphocytes

• T cells mature here

• T cells are nonfunctional without thymus

• T cells mature from cortex → medulla

Thymus

• Filter lymph for pathogens

• Swollen nodes = infection (large quantity of white blood cells)

Lymph nodes

• Lymph tissue in small intestine

• Monitor food for pathogens

• monitors intestinal bacteria

Peyer's Patch

Check air and food for pathogens

Adenoids (tonsils)

• Filters blood

• Stores lymphocytes

• Recycles old RBCs

• Makes fetal RBCs early in development

Spleen

• Lymph tissue in large intestine

• Helps destroy bacteria

• Vestigial organ

Appendix

• Drains upper right body

• Empties into jugular vein

Right lymphatic duct

• Drains rest of body

• Empties into left subclavian vein

Thoracic duct

• Lymph capillaries in small intestine villi

• Absorb fats

• Needed because fats are too large for blood capillaries

Lacteals

thoracic duct empty into

Left subclavian vein

right lymphatic duct empty into

Jugular vein

Plasma

• flows through blood vessels, carrying nutrients, gas, and immune cells to supply all the tissues in the body

• fluid that empties out of the left or right subclavian vein will enter the blood as _

lymphatic valve

Prevent backflow

edema

tumor pressing against a lymphatic vessel could result in