11. Lymphatic system Flashcards
What does the lymphatic system consist of?
Fluid
Vessels
Nodes
Organs
Tissues
What are functions of lymph?
- Assist in returning fluid to venous system
- Filter fluid to assist in immune response.
- Collect fat molecules and large proteins that cannot enter capillary walls.
How is lymph produced?
Not all of interstitial fluid in arteriovenous system drains back into veins/capillaries - lack of pressure. Lymphatic capillaries have wide gaps in walls - allows fluid onto lymphatic channels which can then drain back into the heart.
What are the main lymph drainage roots?
Right side head, neck, chest and right arm drain separately from left side of head, neck, chest, arm, lower body and legs.
Big ducts drain into right + left subclavian veins > heart > superior vena cava
What is Cisterna Chyli?
- An enlarged section of the thoracic duct.
- White Lymph fat is stored here + then pumped back into blood + then the heart.
What is the average diameter of a lymph node?
Approx 1cm/less
Explain the distribution of lymph nodes in the body.
Distributed through network of lymphatic vessels
CLustered in key location - axillae, groins, para-ortic region, neck.
What are the functions of lymph nodes?
- Filter lymph to remove debris + pathogens
- Contain macrophages + lymphocytes to attack and destroy pathogens.
- Contain plasma cells to make vast numbers of lymphocytes when requires.
- Become enlarged during disease
What are the key lymphoid organs + tissues?
Spleen, thymus, tonsils, peyers patches + appendix, bone marrow.
What are 4 characteristics of the spleen?
- Soft vascular organ
- 12cm long
- Dark purple-red colour
- 7cm wide, 3-4cm thick
Where is the thymus gland located?
In the anterior, superior part of the chest
How does the thymus produce T lymphocytes?
Lymphocytes migrate to Thymus from bone marrow.
Thymus educated T cells to distinguish between normal and foreign tissues, before releasing them to lymph nodes, spleen etc.
