WEEK 7 LYMPHATIC SYSTEM FINISHED Flashcards
What is the function of lymphatic vessels?
Assist the C/V system by removing fluid from the tissue spaces of the body, returning fluid to the blood.
What is lymphatic tissue? What is the function of lymphatic tissue?
A type of connective tissue with large numbers of lymphocytes (esp useful for the defence against bacteria and viruses)
What are the 4 functions of the lymphatic system?
Protection and maintenance of the internal fluid environment of the body by producing, filtering and converting lymph and producing various blood cells
Collects surplus tissue fluid
Absorbs and transports fat (small intestine)
Defence
Describe lymph.
Clear colourless fluid found in the lymphatics. This is the name given to tissue fluid once it has entered a lymph vessel.
Where are lymph capillaries usually found? What are they? What are they composed of
Where there are blood capillaries. Form a closed network but with a larger mesh. They are formed by simple endothelial tubes with porous junctions where interstitial fluid, proteins, microorganisms and absorbed fats can easily enter.
Where are lymph capillaries NOT found
Epithelium, epidermis of skin, cartilage, bone, bone marrow, thymus, internal ear, eyeball, placenta, cornea, teeth, CNS or other tissues devoid of blood vessels.
What are sinusoids? Where are they found
Found in the spleen and liver, irregular spaces between cells where blood passes. They act as the sole drainage structures of these 2 organs
What is the function of lymph vessels? What is the diameter of a normal lymph vessel?
Drain the lymph capillary networks. 1/2 to 1 mm diameter
What are lymphaticovenous communications?
Communications between lymphatics and veins.
What is the general rule in regards to which lymph vessels follow which blood vessels?
Superficial follow veins
Deep follow arteries
What are lymph nodes? What colour are they? What shape are they?
A structure through which lymph passes through on its way to the venous system. Found clustered along lymphatic vessels they can vary greatly in size. Packed with lymphocytes and phagocytic cells to help purify the lymph.
They are pink in real life, brown in cadavers.
Bean shaped with a fibrous connective tissue capsule
What are the 2 vessels that enter and exit lymph nodes?
Afferent vessels flow into the nodes
Efferent vessels flow out of the nodes
What is the function of lymph nodes?
Filters lymph
Factors for lymphocytes
Contain antibodies
Bacteria and cancer cells may be stopped and destroyed by phagocytes in the lymph but can sometimes acts as a pathway for cancer spread.
What is lymphoid tissue?
Collections of enormous numbers of migratory and semimigratory lymphocytes and play an important role in immune reactions in the body
Where can lymphoid tissue be found
Lymph nodes Tonsils Follicles in the intestine Appendix Thymus Spleen
What are the 3 main paired lymph trunks?
Jugular - accompanies internal jugular vein in the neck
Subclavian - accompanies subclavian vein in the upper limb
Bronchomediastinal - from the thoracic viscera
Where do the 3 paid lymph trunks end? Where do they pass into?
Either separately or together near the angle between the internal jugular veins and subclavian veins.
They pass into the right lymphatic duct or thoracic duct.
What region does the right thoracic duct drain? What is the exception from this region? What is the rate of flow from the thoracic duct?
Drains the lower extremities, abdomen, pelvis, left thoracic region, left upper extremity, left head and neck
Rate of flow from the thoracic duct in the general circulation is around 125ml her hour during normal exertion
Describe the thoracic duct? Length, location, begins with the convergence of what?
38-45 cm long, 3mm in diameter
Lies anterior to the L1/2 vertebra, between the right and left crus of the diaphragm and aorta.
Begins with the convergence of the main lymphatic ducts of the abdomen.
What is the cisterna chyli? Where does the travel?
The thoracic duct in some people looks like a mall thin walled sac, which gets calls the cistern chyli. It varies in size and shape.
It ascends though the aortic hiatus and then passes into the mediastinum. It then ascends through the thorax and enters the junction between the left internal jugular and left subclavian vein.
How long is the thoracic duct?
What part of the body does it drain?
Where does the drain into?
1.25cm long
Drains the right upper extremity, right thoracic region, right head and neck.
It drains the 3 lymphatic trunks in the upper quadrant to the junction of the right internal jugular and right subclavian veins.
