Intro to lymphatic systems and its diseases

Question 1

What is the lymphatic systems?

Answer 1

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.

Question 2

What is included in the dermal lymphatic vascular network?

Answer 2

-Lymphatic capillaries
-Collecting vessels

Question 3

What are properties of lymphatic capillaries?

Answer 3

• Blind ended
• No smooth muscle
• Incontinuous basement membrane

Question 4

What are properties of collecting vessels?

Answer 4

• Smooth muscle coverage
• Luminal valves
• Basement membrane

Question 5

What is lymph formed from?

Answer 5

Lymph is formed from interstitial (tissue)
fluid

Question 6

What does interstitial fluid originate as?

Answer 6

Interstitial fluid originates as a plasma
filtrate

Question 7

What does lymph contain?

Answer 7

Lymph contains salts, proteins, fat and
cells (the cells are mainly lymphocytes
but also dendritic cells and macrophages)

Question 8

STRUCTURE OF LYMPH NODES

Answer 8

CHECK SLIDE

Question 9

Why is an efficient lymphatic system needed to overcome covid-19 infection?

Answer 9

-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

Question 10

What does a tender lymph gland indicate?

Answer 10

A tender lymph gland indicates
an immune response to infection

Question 11

What are secondary lymphoid organs and what happens here?

Answer 11

The Secondary Lymphoid
Organs (SLOs) are filters where
foreign invaders e.g. microbes,
are captured, and lymphocytes
are activated

Question 12

What are examples of mucosa-associated lymphoid tissue(MALT)?

Answer 12

Mucosa-associated lymphoid tissue(MALT) include tonsils, Peyer’s patches of the small bowel

Question 13

What is included in the lymphatic system?

Answer 13

-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

Question 14

CHECK SLIDES FOR COVID 19 lymph nodes

Answer 14

CHECK SLIDES FOR COVID 19 lymph nodes

Question 15

What is pulmonary oedema in heart failure due to and what does this cause?

Answer 15

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.

Question 16

What does interstitial oedema spill out and what does this interfere with?

Answer 16

This interstitial oedema spills out into the
alveoli and interferes with O2 exchange

Question 17

How does tissue fluid homeostasis work in terms of blood vessels and lymph?

Answer 17

the blood vessels supply fluid, and the lymph drains it away

Question 18

What is tissue fluid formed from?

Answer 18

Tissue fluid is formed from plasma escaping
through the blood vessel wall

Question 19

How does tissue fluid drain?

Answer 19

Tissue (interstitial) fluid drains predominantly
as lymph and not by venous reabsorption

Question 20

What does the subglycocalyx act as?

Answer 20

The subglycocalyx acts as a regulator or
stabiliser for filtration so the default position is no reabsorption

Question 21

Despite what conditions does the lung still generate lymph?

Answer 21

The lung generates lymph even though
pulmonary capillary pressure (10mm Hg)
is much lower than plasma COP (25 mm Hg).

Question 22

Why are pulmonary capillaries in a filtration state and therefore what does this mean for gradient?

Answer 22

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.

Question 23

What does left sided heart failure increase and what occurs if lymph drainage does not increase accordingly?

Answer 23

Left sided heart failure increases pulmonary
capillary pressure, increasing filtration.
Unless lymph drainage increases accordingly,
oedema occurs in lung parenchyma.

Question 24

What is the recommended staging investigation for breast cancer?

Answer 24

Sentinel lymph node biopsy is the recommended staging investigation for breast
cancer

Question 25

Cancer in blood stream?

Answer 25

Cancer cells have a membrane with a polyunsaturated lipids
-Lipid oxidation and cell death by ferroptosis
This results in a low frequency of metastases

Question 26

Cancer in lymphatic vessels?

Answer 26

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

Question 27

What does pitting oedema indicate?

Answer 27

Indicates an excess of interstitial fluid

Question 28

What does pitting oedema a result from?

Answer 28

Results from too much fluid filtration from
blood vessels overwhelming lymph
drainage or too little lymph drainage

Question 29

What does varicose veins or venous engorgement like heart failure create?

Answer 29

Varicose veins or venous engorgement e.g.
heart failure, creates high venous pressure
and increased microvascular fluid filtration
into tissues.

Question 30

When does lymphoedema occur?

Answer 30

Lymphoedema occurs when the dominant fault is a failure of lymph drainage with no increase
in capillary filtration (normal
lymph load)

Question 31

What is a second function of the lymphatic system?

Answer 31

A second function of the Lymphatic System is tissue immunosurveillance and prevention of infection

Question 32

What is cellulitis a common complication of?

Answer 32

Cellulitis is a common complication of impaired
lymph drainage and is often recurrent.

Question 33

What is a third function of the lymphatic system?

Answer 33

A third function of the Lymphatic System is fat transport

Question 34

What does a failure in gut lymphatics result in?

Answer 34

A failure of gut lymphatics results in fat malabsorption

Question 35

What can impaired lymph drainage cause in terms of fat deposition?

Answer 35

Impaired lymph drainage causes increased peripheral tissue fat deposition

Question 36

What is primary lymphoedema due to?

Answer 36

Primary lymphoedema is due to an inborn, presumed genetic, fault in lymph drainage.