Lymphatic System

Lymphatic System

• A vast collection of cells and biochemicals that travel in lymphatic vessels

• Contains a network of vessels that assist in circulating fluids.

• Closely associated with the Cardiovascular System.

Functions of Lymphatic system

• Collecting, filtering & returning fluid

• Protects

• Transports lipids & fat-soluble vitamins

• Maintains homeostasis

Supports homeostasis by…

• Cleans & cycles fluids back into the bloodstream

• Defends the body against diseases which disrupt homeostasis

1st in Lymphatic pathway

Lymphatic capillaries

2nd in Lymphatic pathway

lymphatic vessels

3rd in Lymphatic pathway

lymph nodes

4th in Lymphatic pathway

larger lymphatic vessels

5th in Lymphatic pathway

lymphatic trunks

6th in Lymphatic pathway

lymphatic collecting ducts

7th in Lymphatic pathway

subclavian veins in thorax

Afferent

it goes towards the structure

Efferent

it will exit the structure

Lymphatic vessels

transport fluids back into the blood that have escaped from the blood.

Lymphatic organs

scattered throughout the body tonsils, bone marrow, spleen, lymph nodes, thymus, & appendix

Lymphatic Capillaries

• Similar structure to blood capillaries

• Not found in bone marrow or nervous tissue.

Lymphatic Vessels

• Larger continuations of the capillaries

• Carry Lymph toward the heart

• Like veins, they also contain one-way valves

Lymphatic Trunks parts

• Lumbar Trunk

• Subclavian Trunk

• Intestinal Trunk

Lymphatic Trunks

• Are formed by the union of the largest lymphatic collecting vessels.

• Drain large areas of the body.

Lumber trunk

lower limbs and pelvis.

Subclavian Trunk

axilla (armpits) and arms.

Intestinal Trunk

stomach, intestines, pancreas, spleen, and liver.

Thoracic Duct

Drains lymph from the LEFT side of the head, neck, thorax, and upper limb, and the entire body below the diaphragm

Right Lymphatic Duct

Drains lymph from the RIGHT side of the head, neck, and thorax, and the right upper limb

2 hours is…

First Responders

4 hours is…

Inflammation

6 hours is…

Antiviral Defense

10 hours is…

Antigen Presentation

12 hours is…

T Cell Activation

6 days is…

Antibody Production

7-10 days is…

Memory

First Responders

Phagocytes like neutrophils and macrophages enter the area and engulf pathogens and infected cells

Inflammation

Macrophages release cytokines to activate the immune system while mast cells begin releasing histamine to make the vessels leaky and bring more immune cells to the area

Antiviral Defense

Killer T cells show up and attack infected cells causing them to undergo apoptosis. The cells are then engulfed by phagocytes

Antigen Presentation

The phagocytes begin displaying antigens from the pathogens on their surface to interact with the helper T-cells and trigger the adaptive immune response

T Cell Activation

T-cells (helper and killer) activated by antigen presenting cells to replicate into MANY T-cells, B-cells are also activated by the increased helper T-cells

Antibody Production

B-cells are activated and begin to multiply and differentiate into plasma cells that produce AntiBodies that fight specific pathogens by binding and neutralizing them. Phagocytes take away the neutralized pathogens.

Memory

Most of the B cells and T cells will die by apoptosis. Some remain in small quantities called memory cells. These can be reactivated to multiply quickly to an infection by the same type of pathogen in the future.