Lymphathics Flashcards
what is the function of the lymphatic system
- Drain excess interstitial fluid
- Transport dietary lipids from GI tract into blood
- Protects against invasion through immune responses
- Plays an unwanted role in providing at least one pathway for the spread of malignancy
why do you have an extra 3 litres of lymphatic fluid a day
- Low hydrostatic pressure, high osmotic pressure - causes fluid do move out into the capillary
- High hydrostatic pressure low osmotic pressure - causes fluid to move in out of the capillary
- 17 litres moving into the interstitial during the day
- 20 litres move out
- Therefore, every day you have an excess 3 litres a day – lymphatic system is draining this fluid
what are the properties of lymphatic system
- has one way endothelium tubes
- these take the fluid away from the capillary bed
- ## have a discontinuous basement membrane or the don’t have a membrane at all
how large is the largest lymphatic duct
- Lymphatic duct is 2mm wide and these are the largest lymph vessels present in the body
where do the lymphatic vessels drain towards
- Lymphatic vessels drain towards the lymph nodes – these act as of filters lymph
what is elephantitis caused by
- it is caused by a round worm infection of lymph nodes that block the lymphathetic drainage so this can cause interstitial fluid build up in the tissues
what are the two parts of a lymph node
outer cortex
inner medulla
- this is surrounded by an outside capsule
where are the lymphocytes present in a lymph node
- they are present in the outer cortex
describe drainage of the lymph nodes
- There are afferent vessels drain into the cortex where the lymphocytes are
- Lymph travels from the cortex into the medulla
- then in the medulla there are lymphatic vessels that drain from the medulla into another lymph node or into a duct
what are lymph nodes
Lymph nodes are small masses of lymphoid tissue located along the length of the lymphatic vessels through which lymph is filtered.
where does the thoracic duct run
- runs in the posterior mediastinum
- between the aorta and azygous vein
where does the thoracic duct start
starts in the abdomen in the cisterna chyli
- lymph from the abdomen drains into it
where does the thoracic duct drain into
drains into the left venous angle (internal jugular vein meets the subclavian vein)
what is the left sternal angle
- where the left internal jugular vein meets the left subclavian vein
what is the right sternal angle
- where the right internal jugular vein meets the right subclavian vein
what is the major lymphatic duct
- the thoracic duct
what is the drainage that drains in the supraclavicular lymph nodes
- drainage goes into the thoracic duct from this region
- the supraclavicular lymphs drain into the thoracic node
what cancer is commonly associated with swollen supraclavicular lymph nodes
stomach cancer
- could be from any 3/4 of the body as a 3/4 of the body drains into the thoracic duct
what happens in lymph leaks into the pleura cavity
if there is laceration of the thoracic duct it leaks lymph into the pleura cavity this is called a chylothorax
what are the two types of lymphatic vessels
superficial
deep - these follow venous drainage
what are the two types of lymph nodes
superficial and deep
what are the superficial lymph nodes
- cervical
- axillary
- inguinal
where are the superficial cervical lymph nodes
- around the external jugular vein
-
what vein is on top of the SCM
external jugular vein
what vein is below the SCM
intneral jugular vein
where are the deep cervical lymph nodes
under the internal jugular vein
- vertical chain along the IJV,
- efferent vessels form the right jugular trunk