How would you describe the Lymphatic system?
It is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials.
Note : It is the body drainage system.
What is the primary function of the Lymphatic System?
To transport lymph, a fluid containing infection-fighting WBCs throughout the body.
How important is the lymphatic system?
It helps maintain homeostasis(fluid balance) by draining excess interstitial fluid as well as providing the mechanisms for defense against disease and infection.
What is tissue fluid?
A fluid also known as interstitial fluid that fills the spaces between individual cells that is in osmotic contact with the blood and lymph.
What is the purpose of tissue fluid?
It is responsible for interstitial transport of nutrients and wastes.
What are the structures of the Lymphatic System?
- Lymphatic drainage vessels
- Lymph nodes and other lymphatic tissue
- Thymus gland
The ___________ is considered as the second circulating system of the human body.
The lymphatic tissue can also be referred as ____________.
The lymphoid tissue performs ______________.
What is lymph?
It is tissue fluid that enters lymph capillaries.
It is a clear fluid.
What are the functions of the lymphatic system?
Drainage of excess interstitial fluid(From tissue spaces to the bloodstream).
For transport of dietary lipids.
Carries out immune responses.
What are the primary lymphatic organs?
- Red bone marrow
- Thymus glands
What is the purpose of the Red Bone Marrow in regards to lymphatic system?
The RBM produces stem cells that give rise to Mature B cells and to pre-T cells.
__________ migrate from the RBM to the thymus and mature there to become _________.
Pre-T cells ; T-cells
What are the secondary lymphatic organs?
- Lymph nodes
- Lymphatic tissue
Interstitial fluid is a _________ of blood plasma.
What is the benefit of having fewer efferent than afferent lymphatics in lymph nodes?
Having fewer efferents causes lymph to accumulate in lymph nodes, allowing more time for its cleaning.
Describe the structure of lymphatic vessels?
Thin-walled valved structures that carry lymph.
The lymph vessels consists of which layers?
- Endothelial cells(inner)
- Thin layer of smooth muscle(middle)
How is lymph flow maintained in the body?
Lymph flow is maintained by lymphokinetic actions of breathing and skeletal muscle movement.
Note: The lymphatic system is not a closed system like the circulatory system.
What is the importance of valves in lymphatic vessels?
They ensure the one-way movement of lymph that is they prevent back flow of lymph.
How is the movement of lymph inside a lymphangion?
When the pressure inside a lymphangion becomes high enough, lymph fluid will push through the semi-lunar valve into the next lymphangion, while the valve then closes.
Describe the lymph capillaries?
Single layer of overlapping endothelial cells.
Permeable to all interstitial fluid constituents including proteins and cell debris.
Lymph capillaries are absent in:
Brain, Spinal cord, Splenic pulp and bone marrow.
Where are lymph capillaries located?
They are located in tissue spaces next to blood capillaries.
The human circulatory system processes how much litres of blood per day?
An average of 20 L of blood per day through capillary filtration, which removes plasma from the blood.
How much of the filtered plasma is reabsorbed directly into the blood vessels?
Roughly 17 litres.
After capillary filtration of blood, how much of the filtered plasma remains in the interstitial fluid?
One of the main function of the lymphatic system is to provide an _______________ to the blood for the surplus ____ of excess interstitial fluid.
accessory return; 3 litres
Lymph before it passes through lymph nodes constitutes of what?
- Waste products
- Cellular debris
What are lacteals and its function?
They are specialized lymph capillaries in the villi of the small intestine.
They absorb the fat-soluble end products of digestion such as fatty acids and vitamins A, D, E and K.
How does Edema(swelling) occurs?
Due to the build up of fluids in tissue.
What are the factors that can increase lymph flow?
- Physical activity
- Postural changes
- Arterial pulsations