LYMPHATIC SYSTEM Flashcards
- Returns fluids that leaked from vascular system back to the blood
- Protects the body by removing foreign material from the lymph
- Immune surveillance
Functions of the lymphatic system
Lymphatic System consists of the semi-independent parts:
- Lymphatic vessels
- Lymphatic organs
Distribution of Lymphatic vessels
Lymphatic capillaries
Lymphatic vessels
Lymphatic trunks
Lumbar
Intestinal
Bronchomediastinal
Subclavian
Jugular
Lymph Trunks
- Lumbar - drains lower extremities and pelvis
- Intestinal - drains abdominal region
- Bronchomediastinal - drain thorax
- Subclavian - drains upper extremities
- Jugular - drains head and neck
drain thorax
Bronchomediastinal
drains lower extremities and pelvis
Lumbar
drains abdominal region
Intestinal
drains head and neck
Jugular
drains upper extremities
Subclavian
Lymphatic Channels
- thoracic duct
- right lymphatic duct
- originates from cisterna chyli
- which empties into the left subclavian vein at its junction with the left internal jugular vein
thoracic duct
- which empties into the right subclavian vein at its junction with the right internal jugular vein
right lymphatic duct
Lymph Transport
- Skeletal muscle contraction
- Negative pressure in the thorax
- Valves
- Lymphocytes aggregates
* loose, dense, nodular, follicles - Loose connective tissue: reticular
- Epithelial cells
Lymphatic Organs Basic structural components:
- Located along lymphatic vessels
- macrophages that phagocytize bacteria
- Lymphocytes mounting immune response
- Filters the lymph
Lymph Node
- is a flat, pinkish-gray, two lobed organ lying high in the chest anterior to the aorta and posterior to the sternum.
- increases its size during childhood
- characteristic feature is hassal’s or thymic corpuscles
- In the thymus the lymphoid tissue is not arranged in nodules
Thymus
- largest lymphatic organ
- located at the left hypochondriac region
- graveyard for senescent or aged RBC
- filters the blood
- produces lymphocytes and plasma cells
Structure
* Capsule
* Contains lymphocytes, macrophages, RBC
* Red pulp
* White pulp
Spleen
o contains abundant RBC and macrophages
Red pulp
- Lymphatics develop as out pocketing of developing vein, from mesoderm
- Thymus gland develops from endoderm
- The rest of the lymphoid organs develop from mesoderm
Developmental Aspect of The Lymphatics
o contains lymphocytes
White pulp
Tonsils
Waldeyer’s ring
- Gut associated lymphatic tissue (GALT)
- Clusters of nodules in the ileum
- Macrophages are in ideal position to capture and destroy bacteria, preventing
them from reaching the intestinal wall.
Peyer’s Patches
several groups of tonsils forming a ring of lymphoid tissue, guard the entrance of the alimentary and respiratory tracts from invasion by microorganisms.
Waldeyer’s ring
Components of this ring are:
- Palatine tonsils
- Nasopharyngeal tonsil
- Lingual tonsils
