Principles of Lymphatics

Question 1

what are the main ducts that drain lymphatic fluid?

Answer 1

• right lymphatic duct.

- thoracic duct.

Question 2

what does the right lymphatic duct drain?

Answer 2

-drains right upper limb, right side of head/neck and right side of chest wall/abdomen

Question 3

what does thoracic duct drain?

Answer 3

drains everything else.

Question 4

histology of lymphatic vessels?

Answer 4

• have valves
• very little connective tissue
• no smooth muscle
• blind-ending vessels are lymphatic since blood vessels are circulatory.

Question 5

what is the function of the lymphatic system?

Answer 5

1. physical role.

2. immunological role.

Question 6

what lies under physical role of lymphatic system?

Answer 6

• drainage and filtering of extracellular fluid.
• every subcutaneous injection is injecting into the lymphatic system.
• avascular tissue does not require lymphatics (e.g. cartilage, hair, nails, cornea)
• some vascular tissue share unique blood-tissue barriers hence do not contain lymphatics.

Question 7

what lies under immunological role of lymphatic system?

Answer 7

• lymph can provide early and efficient warnings of infections
• recognition of foreign antigens through immunological cells that are located in lymph nodes.
• production of antigen specific cells (B and T cells)

Question 8

what is hydrostatic pressure at arterial end of blood vessels?

Answer 8

high hydrostatic pressure - causes proteins and water to leak out.

Question 9

what is hydrostatic pressure at venous end of blood vessels?

Answer 9

low hydrostatic pressure - causes proteins and waters to drain in.

Question 10

how efficient is the physical drainage role of lymph?

Answer 10

90% efficient/ the rest of the fluid is drained by lymph.

Question 11

where is the fluid from lymph go?

Answer 11

recycled into the systemic vascular circulation - goes into a big vein and into the heart.

Question 12

structure of lymphatic channels?

Answer 12

most lymphatic channels have valves but no smooth muscle

Question 13

direction of low in lymphatic channels?

Answer 13

unidirectional.

Question 14

what helps with lymph flow?

Answer 14

• muscle movements

- traveling with arteries and veins to get benefit of pulsing motion.

Question 15

fluid in lymphatic vessels and filtration?

Answer 15

all fluid in lymphatic vessels is filtered through at least 1 lymph node.

Question 16

how does lymphatic system contribute towards forming adaptive immune system?

Answer 16

process of filtering and immune cell function in the lymph nodes is the basis for forming an immunological memory in the adaptive immune system.

Question 17

what does the process of filtering refer to?

Answer 17

-cels in lymph nodes help remove debris and filter for foreign particles via phagocytosis.

Question 18

what is immune cell function of lymphocytes?

Answer 18

lymphocytes may recognise foreign proteins and trigger and immunological response.

Question 19

How does filtering of tissue fluid via lymph nodes occur?

Answer 19

1. fluid enters through afferent vessels.
2. comes in contact with the cortex where T cells are located.
3. fluid passes through germinal centres where B cells mature, differentiate and proliferate.
4. fluid arrives at medullary sinus, where macrophages help phagocytose debris.
5. filtered fluid leaves through efferent vessels

Question 20

what are sentinel nodes?

Answer 20

first few lymph nodes into which a tumour drains.