Intro to lymphatic systems and its diseases Flashcards
What is the lymphatic systems?
Lymphatic system acts as a countercurrent
system draining from the tissues all waste materials and recycling surplus
fluid, salts, proteins, fat and immune cells back to body.
What is included in the dermal lymphatic vascular network?
-Lymphatic capillaries
-Collecting vessels
What are properties of lymphatic capillaries?
- Blind ended
- No smooth muscle
- Incontinuous basement membrane
What are properties of collecting vessels?
- Smooth muscle coverage
- Luminal valves
- Basement membrane
What is lymph formed from?
Lymph is formed from interstitial (tissue)
fluid
What does interstitial fluid originate as?
Interstitial fluid originates as a plasma
filtrate
What does lymph contain?
Lymph contains salts, proteins, fat and
cells (the cells are mainly lymphocytes
but also dendritic cells and macrophages)
STRUCTURE OF LYMPH NODES
CHECK SLIDE
Why is an efficient lymphatic system needed to overcome covid-19 infection?
-Lymph vessels absorb the microbes responsible for an infection and transport them to lymph glands for acquired immunity
-It is in lymph glands where immune cells become sufficiently developed to produce the specific
What does a tender lymph gland indicate?
A tender lymph gland indicates
an immune response to infection
What are secondary lymphoid organs and what happens here?
The Secondary Lymphoid
Organs (SLOs) are filters where
foreign invaders e.g. microbes,
are captured, and lymphocytes
are activated
What are examples of mucosa-associated lymphoid tissue(MALT)?
Mucosa-associated lymphoid tissue(MALT) include tonsils, Peyer’s patches of the small bowel
What is included in the lymphatic system?
-Waldeyer’s ring(tonsils, adenoids and lymph nodes)
-Lymph nodes
-Bronchial-associated lymphoid tissue
-Spleen
-Peyer’s patches
-Mesenteric lymph nodes
-Urogenital lymphoid tissue
-Lymph nodes
CHECK SLIDES FOR COVID 19 lymph nodes
CHECK SLIDES FOR COVID 19 lymph nodes
What is pulmonary oedema in heart failure due to and what does this cause?
Pulmonary oedema in heart failure is due
to raised pulmonary venous pressure
causing increased amounts of interstitial
fluid which is not sufficiently cleared by
lymph so congesting the lung.
What does interstitial oedema spill out and what does this interfere with?
This interstitial oedema spills out into the
alveoli and interferes with O2 exchange
How does tissue fluid homeostasis work in terms of blood vessels and lymph?
the blood vessels supply fluid, and the lymph drains it away
What is tissue fluid formed from?
Tissue fluid is formed from plasma escaping
through the blood vessel wall
How does tissue fluid drain?
Tissue (interstitial) fluid drains predominantly
as lymph and not by venous reabsorption
What does the subglycocalyx act as?
The subglycocalyx acts as a regulator or
stabiliser for filtration so the default position is no reabsorption
Despite what conditions does the lung still generate lymph?
The lung generates lymph even though
pulmonary capillary pressure (10mm Hg)
is much lower than plasma COP (25 mm Hg).
Why are pulmonary capillaries in a filtration state and therefore what does this mean for gradient?
Pulmonary capillaries are in a filtration state
because pulmonary interstitial protein
concentration is high (70% of plasma). The
COP gradient is therefore lower than the
Hydraulic pressure gradient.
What does left sided heart failure increase and what occurs if lymph drainage does not increase accordingly?
Left sided heart failure increases pulmonary
capillary pressure, increasing filtration.
Unless lymph drainage increases accordingly,
oedema occurs in lung parenchyma.
What is the recommended staging investigation for breast cancer?
Sentinel lymph node biopsy is the recommended staging investigation for breast
cancer
Cancer in blood stream?
Cancer cells have a membrane with a polyunsaturated lipids
-Lipid oxidation and cell death by ferroptosis
This results in a low frequency of metastases
Cancer in lymphatic vessels?
Cancer cells are coated by monosaturated, oleate-containing lipids
-These circulate into lymph nodes and then go into lymph nodes where there is a high frequency of metastases
What does pitting oedema indicate?
Indicates an excess of interstitial fluid
What does pitting oedema a result from?
Results from too much fluid filtration from
blood vessels overwhelming lymph
drainage or too little lymph drainage
What does varicose veins or venous engorgement like heart failure create?
Varicose veins or venous engorgement e.g.
heart failure, creates high venous pressure
and increased microvascular fluid filtration
into tissues.
When does lymphoedema occur?
Lymphoedema occurs when the dominant fault is a failure of lymph drainage with no increase
in capillary filtration (normal
lymph load)
What is a second function of the lymphatic system?
A second function of the Lymphatic System is tissue immunosurveillance and prevention of infection
What is cellulitis a common complication of?
Cellulitis is a common complication of impaired
lymph drainage and is often recurrent.
What is a third function of the lymphatic system?
A third function of the Lymphatic System is fat transport
What does a failure in gut lymphatics result in?
A failure of gut lymphatics results in fat malabsorption
What can impaired lymph drainage cause in terms of fat deposition?
Impaired lymph drainage causes increased peripheral tissue fat deposition
What is primary lymphoedema due to?
Primary lymphoedema is due to an inborn, presumed genetic, fault in lymph drainage.
