Lymphatic System Flashcards
What are the two main functions of the Lymphatic system?
- Transport (materials which are too large to be carried by the capillaries)
- Facilitate the immune response
- The lymphatic system begins as a blind ended ___ ___ in tissues spaces between cells
- ____ ____ drains into these structures forming _____
- Lymphatic capillaries merge to form larger vessels, called ____ ____, which transport lymph into and out of the _____ _____.
- Lymphatic Capillaries
- Interstitial Fluid — Lymph
- Lymphatic Vessles — Lymphatic Nodes
How does the lymphatic capillary mini-valve let interstitial fluid into the capillary?
- The endothelium of the capillary has mini-valves which overlap, they are forced open due to fluid pressure out of the capillary
- Interstitial fluid drains into the capillary, turning into lymph
- increasing fluid pressure in the lymphatic capillary forces the overlapping endothelium valves to close, meaning lymph cannot escape.
How permeable are the capillary mini-valves?
Highly permeable, they let all substances in.
What are anchoring filaments?
- Filaments which are attached to the endothelium of lymphatic capillaries, anchoring and providing rigidity to the cell
- They are needed as the overlapping valve structure of the endothelial capillary cell means it is not very rigid
What are properties of Lymphatic (collecting) vessels?
- Lymphatic Valves (to help build pressure to move lymph up the body)
- Large lumen (to accomodate the valves)
- Thin walls (they have the three tunics though, Tunica Intima, Tunica Media, Tunica Externa)
What are the main functions of lymph nodes?
- Destruction - foreign substances and cell debris
- Activates Immune response
What are the names of the defence cells within the lymph nodes?
- Macrophages - helps with destruction
- Lymphocytes - helps with activating immune response
How many lymph nodes does lymph travel through before reaching the heart?
Approximately 8-10
On average how many lymph nodes does a human have?
About 100
How much lymph is returned to the blood in a day?
3 Litres
what regions of the body does the Right Lymphatic Duct drain?
Head, right arm, and right thoracic region
What region of the body does the left lymphatic (or thoracic) duct drain?
Rest of the body
How does lymph get into the blood supply?
Through the subclavian veins which form together to form the superior vena cava
What is the passage of fluid from the arteries?
- Arteries (blood)
- Arterioles (blood)
- Blood capillaries (blood)
- Interstitial spaces (interstitial fluid)
- Lymphatic capillaries (lymph)
- lymphatic vessels (lymph)
- lymphatic trunk (lymph)
- lymphatic duct (lymph)
- subclavian veins (blood)
- Superior vena cava (blood)
- Heart (blood)
What are the primary lymphatic organs and tissues?
- Thymus
- Red Bone Marrow