lymphatic system

Question 1

what are the 2 main functions of the lymphatic system?

Answer 1

• collect tissue fluid that escapes blood capillaries and return it back to the CS
• provide defence against invading disease causing organisms

Question 2

what does the lymphatic system consist of?

Answer 2

lymph fluid
lymph vessels( with valves)
lymph organs- spleen, bone marrow, tonsils, thymus
lymph nodes or called lymph glands
lymph tissue( surrounds nodes)
lymphocytes ( WBC found in the lymph nodes)
lymphatic ducts x2 - right/left ( found above the heart)

Question 3

what is a lymph? where does it come from

Answer 3

• it is a colourless fluid found in lymph vessels that will eventually return to blood
  -lymph contains lymphocytes, pathogens, macrophages
• a lymph comes from plasma(liquid part of blood) that can leak out of the blood capillaries due to high pressure, plasma ends up between cells (tissue fluid)
  fluid needs to be collected from between the cells otherwise is will accumulate and cause swelling( oedema)
  the lymph vessels pick up the extra fluid and drain it back into the CS via left/ right ducts.

Question 4

what are lymphatic ducts?

Answer 4

• 2 points of entry for returning lymph back into CS
  -2 points are called left/right lymphatic ducts

Question 5

what are lymph nodes?

Answer 5

they are specialised cells that contain lymphocyte, macrophages and plasma that defend the body from invading micro organisms

Question 6

where are lymph nodes found?

Answer 6

along lymphatic vessels- neck, groin, armpits, others

Question 7

describe what structures, cells, tissues are found in a lymph node?

Answer 7

surrounded by a capsule of connective tissue

Question 8

describe the role of the lymphatic system in defence against disease?

Answer 8

lymph entering nodes may contain pathogens, foreign materials
- lymphocytes can detect foreign antigen/ material and multiply in an effort to defend body
- macrophages/ phagocytic cells carry out phagocytosis and ingest the foreign substance
- enzymes are released by the macrophage that break substances down
- lymph nodes swell/ feel pressure due to increase in production of lymphcytes.

Question 9

what is the difference between the CS and the LS?

Answer 9

CS
- blood is red from Hb
- veins are the only vessels with valves
- blood vessels are not blind ended
- CS is a network of vessel transporting
- blood in a circuit/ circle
- movement of blood is by heart
- movement by heart and in veins and valves
LS
- lymph fluid is colourless
- all lymphatic vessels have valves
- lymph vessel are blind ended
- flow of lymphatic system is one way ending at the ducts
-no pump
- skeletal muscles and valves move the lymph