Lecture: The Lymphatic System Flashcards
What is the job of the lymphoid system?
Protect against disease (produce maintain distribute lymphocytes)
What 3 things cause the lymphoid system to respond?
Environmental pathogens Toxins Abnormal body cells, such as cancers
What role do lymphocytes play?
Identify, attack, and develop immunity as part of the immune response
What is immunity?
The ability to resist infection and disease
What makes a defense ‘nonspecific’
Blocks or attacks potential infectious organism but they cannot distinguish one attack from another.
What is lymph?
Interstitial fluid similar to plasma but does not have plasma proteins
What do lymphatic vessels do?
Carries lymph from peripheral tissues to the venous system
What 4 parts make up the lymphoid system?
Lymph, Lymphatic Vessels, Lymphoid tissues + organs, Lymphocytes and other cells
What 3 places are lymphocytes produces in?
Lymphoid tissues, Lymphoid organs, Red bone marrow
What 2 things do lymphocytes do?
Detects problems + travel to site of injury or infection
How do lymphocytes circulate?
From blood > Interstitial Fluid via capillaries > to venous blood via lymphatic vessels
How do fluids circulate?
Blood > Lymph > Venous system
What carries lymph?
Lymphatic Vessels
The lymphoid system begins with…?
Lymphatic Capillaries (the smallest vessels)
4 anatomical ways that lymphatic capillaries differ from blood capillaries?
- Start as pockets rather than tubes
- larger diameter
- thinner walls
- parts are flat or irregular
What is the structure of a lymphatic capillary?
Loosely bound, overlapping endothelial cells
How do the valves in lymphatic capillaries “work”
Overlap in endothelial cells act as 1 way valve, letting fluids, solutes, viruses and bacteria in, prevents return to intercellular space.
What is a lacteal?
Are special lymphatic capillaries in small intestine
What do lacteals do?
Transport lipids from digestive tract
What are the primary lymphoid organs?
Bone marrow + thymus
What are secondary lymphoid organs?
Lymph node, spleen, tonsils, peyers patches in intensive and appendix.
Lympathic vessels travel with _____?
Veins
Where is the vermiform appendix?
Right iliac or inguinal region.
What are deep lymphatics?
larger vessels that accompany deep arteries and veins