Session 4- The Lymphatic System Flashcards
What are the functions of the lymphatic system?
- Keeps blood volume levels where they should be
- Keeps blood pressure high enough
- Fight off infection
What are the 5 major components of the lymphatic system?
- Vessels
- Nodes
- Tonsils
- Spleen
- Thymus
Lymph is rich in _____________ and _________ compared to water
Protein
Cells
Lymph does not contain ______________ as they __________________________________________________.
Red blood cells
Are too large to pass though capillary membranes
The lymphatic system functions to ____________ fluid and ____________/___________ lymph as it flows through it.
Reabsorb
Monitor/Cleanse
Transfer of waste and nutrients occurs at the _______________ due to the high pressure at the ____________ end which causes plasma to be forced out into ____________.
Capillary bed
Arteriole
Interstitial fluid
At the capillary bed, plasma is drawn back into the circulatory system at the __________ end due to high _________ pressure.
Venule
Osmotic
How much plasma is forced through the arteriole end of the capillary bed each day? How much of this is taken up at the venular end?
20L is forced through
17L is taken up
What happens to the other 3L of plasma that is not taken up at the venular end of the capillary bed?
It enters the lymphatic system as lymph and is later returned to the blood to maintain BP.
Lymphatic capillaries are all over the body, but at notably absent from which locations?
Bones
Bone marrow
Teeth
CNS
If the CNS does not have lymphatic capillaries, where does the excess fluid drain into?
The cerebrospinal fluid (CSF)
Lymphatic capillaries are made up of what kind of cells?
How are they arranged and why?
Endothelial cells
Loosely overlap with each other
To form flap-like mini valves
What features (of the vessels themselves and in the body in general) enables lymphatic vessels to operate at low pressures? Which of these is most important?
Valves Smooth Muscle in the vessel walls SKELETAL MUSCLE MOVEMENT*** Pressure changes in the thorax due to breathing (Negative pressure when breathing in) Pulsation of adjacent arteries
Capillaries—–> Larger lymphatic vessels——> Larger trunks——> ?? & ??
Right lymphatic duct
Left lymphatic duct
From the RIGHT lymphatic duct, lymph drains from where to which component of the circulatory system?
From the UPPER right torso, right arm and right side of head and throat
Into the INTERNAL JUGULAR VEIN
Lymph entering the LEFT lymphatic duct drains from where and into which component of the circulatory system?
From the rest of the body that the right lymphatic duct does not take into account
Into the SUBCLAVIAN VEIN
A blockage of the lymphatics can be caused by what?
A tumour (lymphoma) A worm
A blockage of the lymphatic system will lead to what?
Oedema
As a result of occlusion of the lymphatic system, oedema can occur which can lead to what as a result?
Occlusion–>Oedema–> _________–>__________–>___________
–>___________/__________
Reduced blood flow
Static Fluid
Infection
Cellulitis/Ulceration
Bacteria is able to enter the body by infiltrating some of the ___________, __________ connective tissue under the skin
Loose
Areolar
Once it has entered the tissue, bacteria is able to drain into the lymphatics as tissue is full of ___________ _________.
Interstitial fluid
True of false:
Infections are mostly localised to particular tissues and don’t usually enter the circulation
TRUE
There are approximately how many lymph nodes in the body?
700
How do lymph nodes prevent bacteria from entering the circulation?
By closely and regularly inspecting it using its resident lymphocytes and eliciting an appropriate immune response based on this
Lymph nodes contain which cells?
T cells B cells Macrophages Neutrophils Follicular dendritic cells Reticular cells
What is the function on the reticular cells of the lymph nodes?
They make up the scaffolding network to provide support to all other cells in the lymphatic tissue.
Where do lymphocytes mature?
In the loose reticular connective tissue of the lymph nodes and other lymphoid organs
If a lymph node is overwhelmed by the invader, it may become ___________. This is often an indicator of what?
Inflamed
Infection/Disease
The medulla of the lymph node contains which lymphocyte type?
Both T cells and B cells
The outer cortex of the lymph nodes contains which lymphocytes?
Dividing B cells