Blood, Lymphatic and Immune 1 Flashcards
Definition:
Complex collection of cells and organs whose purpose is to destroy or neutralize pathogens that would otherwise cause disease or death
Immune system
Definition: Lymphatic system
System composed of vessels, cells, and organs which are responsible for carrying excess fluids to the bloodstream as well as fluids to the bloodstream as well as filtering pathogens from our blood
What are 2 examples that describe how closely connected our immune system and lymphatics systems are?
Swelling of the lymph nodes during an infection and the transport of lymphocytes via the lymphatic vessels
What are the 3 main functions of the lymphatic system?
- Drain interstitial fluid
- Help carry out immune responses
- Transport dietary fats
Why does the lymphatic system need to drain interstitial fluid?
Hydrostatic pressure causes leakage of the capillaries resulting in the accumulation of fluid in the interstitial space between the individual cells of tissues
What % of interstitial produced each day is reabsorbed? What happens to the rest?
85%, the remaining 15% of the interstitial fluid is absorbed by the lymphatic system as lymph
Where does the excess fluids go?
Drained back into the bloodstream via a series of vessels, trunks, and ducts
How do lymphatic vessels play a role in the immune system?
Transport immune cells throughout the body
Definition: Major staging area for the development of critical immune responses
Lymph nodes
Definition: Vessels where interstitial fluid enters the lymphatic system and becomes lymph
Lymphatic capillaries
Where are lymphatic capillaries located?
Interlaced among many of the arterials and venues of the circulatory
Definition: Lacteals
Located in the SI, critical for the transport of dietary lipids and lipid-soluble vitamins to the bloodstream
What is chyle?
Dietary triglycerides combine with other lipids and proteins and enter the lacteals to form a milky fluid which is chyle
Where does chyle go?
Travels through the lymphatic system, eventually entering the liver and then the bloodstream
What makes up lymphatic capillaries? Why is it designed this way?
Simple layer of endothelial cells. This allows interstitial fluid to flow into them as interstitial pressure increase
When interstitial pressure is low….
Endothelial flaps close to prevent backflow
What is the major difference between the lymphatic and the cardiovascular system?
Lymph is not actively pumped like blood is by the heart
How is lymph forced through lymphatic vessels?
- movements
- contraction of skeletal muscles during body movements
Movements associated with breathing
What do the lymphatic vessels merge to form?
Lymphatic trunks
Where does lymph from the upper right side of the body go?
Into the right lymphatic duct
Lymph from where enters the bloodstream through the thoracic duct on the left side via all remaining lymphatic trunks?
Everywhere except upper right side of the body
Explain the movement of lymph.
Flows from the lymphatic capillaries through lymphatic vessels, and then is dumped into the circulatory system via the lymphatic ducts located at the junction of the jugular and subclavian veins in the neck. A series of one-way semi-lunar valves keep the lymph moving toward the ducts and the heart
Review structure of the lymphatic system.
Interstitial fluid —> lymph capillaries —> lymph vessels/lymph nodes —> lymph trunks —> lymph ducts —> subclavian veins
