LYMPHATIC SYSTEM

GOODLUCK

Lymph

* Tissue fluid (interstitial fluid) that enters the lymphatic vessels


* Essentially a drainage system accessory to venous system
* Larger particles that escape into tissue fluid can only be removed via lymphatic system

Functions of lymphatic system

* Network that filters antigens from the interstitial fluid
* Primary site of immune response from tissue antigens
* Lymphatic drainage in all organs of the body except brain, eyes, marrow and cartilage
* Flaccid thin walled channels → progressive caliber
* 600 lymph nodes in body
* Slow flow, low pressure system returns interstitial fluid to the blood system

Tissue fluid

________ (interstitial fluid) that enters the lymphatic vessels.

Components of lymphatics

* Lymph
* Lymphatic Vessels
* Lymphatic Organs
* Lymphatic cells

Lymphatic capillaries

Features of structure:

* Blind end
* Single layer of overlapping endothelial cells
* More permeable than that of blood capillary
* Absent from avascular structures, brain, spinal cord splenic pulp and bone marrow

Lymphatic Vessels

* Three layered wall but thinner than vein
* More numerous valves than in vein
* Interposed by lymph nodes at intervals
* Arranged in superficial and deep sets

Lymph Trunks

* Right and left jugular trunks
* Right and left subclavian trunks
* Right and left broncho mediastinal trunk
* Right and left lumbar trunks
* Intestinal trunk

Lymphatic ducts

* Right lymphatic duct
* Thoracic duct

Lymphatic cells

* Also called lymphoid cells
* Located in both the lymphatic system and the cardiovascular system.
* Work together to elicit an immune response.

Types of lymphatic cells

* Macrophages
* Epithelial cells
* Dendritic cells
* Lymphocytes

Primary organs

* Red bone marrow
* Thymus gland

Secondary organs

* Lymph nodes
* Lymph nodules
* Spleen

Lymph nodes

* Capsular shell
* Fibroblasts and reticulin fibers
* Macrophages
* Dendritic cells
* T cells
* B cells

Head and Neck Nodes

Axillary nodes

Inguinal Lymph Nodes

Lymphargitis

* Inflammation of the lymph vessels
* Commonest cause bacteria called streptococcus pyogenes (most common).
* Lymph vessels appear as red streaks through the skin 

Filariasis

Lymphedema

* Occurs due to accumulation of lymphatic fluid in the interstitial tissue
* Sometimes can be appreciated after wearing tight clothing or jewelry on affected limb

Lymphadenopathy

* Means a disease of the lymph nodes
* Lymph nodes become swollen/ enlarged and may be painful to touch

Lymphomas

Cancers originating either from the lymphocytes in the lymph nodes or the lymphatic tissue in organs

Tonsillitis

* Infection of the pharyngeal tonsils
* Tonsils are swollen, Fever and pain during swallowing usually present

Formation and transport of tissue fluid