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
what do the superficial cervical lymph nodes drain
mainly drain superficial parts of head and neck eg. Occipital, parotid, buccal, submental, submandibular, retro auricular, these all drain towards superficial cervical lymph nodes – drains the tongue, tonsils, pinna, scalp, neck, thorax
what do the deep cervical lymph nodes drain
- Deep cervical nodes drain most of the tongue, tonsils, pinna, parotid, oropharynx, nose, paranasal sinuses, palate, larynx, trachea, oesophagus, middle ear
when are lymph nodes most palpable
when they fight infections
what are infected lymph nodes like
- firm
- tender
- enlarged
- warm
what do lymph nodes feel like if they are malignant
firm non tender, matted, (stuck to each other) fixed and increase in size over time
right anterior cervical adenopahty is …
right anterior cervical adenopathy is secondary to metastatic cancer
what does a radical neck dissection involve doing
- Radical neck dissection involves the removal of SCM, IJV and the spinal accessory nerve and the cervical lymph nodes.
what is metastatic neck disease a sign of
- spread of head and neck squamous cell carcinoma from primary sites
- primary sites most commonly involved in the spread of this carcinoma re the mucosal areas of the upper digestive tract
what are the two procedures today that are used to get rid of the cervical lymph nodes
modified radical (leave 1+ structure)
the selective neck dissections (leave 1+ LN group).
what drains into the axillary lymph nodes
- 75% of the lymph from the breast drains towards the lymph nodes
describe the lymphatic drainage of the breast in terms of where it goes
- 75% of the lymph from the breast drains towards the lymph nodes
- Remaining 25% drains towards the parasternal nodes
what are the three groups of axillary lymph nodes in the axilla
- Humeral
- pectoral
- sub scapular
describe the three groups of axillary lymph nodes in the axilla
- Humeral - these are close to the axillary pulse, this is where most lymph from the upper lymph drains
- pectoral - anterior border of chest wall
- sub scapular - posterior border of chest wall
describe where the three groups of axillary lymph nodes drain
- all three drain towards the central axillary lymph nodes
- these drain towards the apical lymph nodes
- these drain to the supraclavicular nodes
- these drain towards the right or left venous angle
what does a radical mastectomy involve
- radical mastectomy involves the removal of all breast tissue, along with the nipple, axillary lymph nodes and a portion of pectoralis major. This is rarely performed today.
what does a modified radical mastectomy involve
- A modified radical mastectomy involves removal of the breast, nipple and most axillary lymph nodes.
describe how you identify what lymph nodes have cancer present in them
- Selects the lymph node that you are going to take out
- First lymph node that tumour will reach,
- Inject tumour with radioactive substance or dye
- Let it drain and scan for where the radioactive dye has gone and then remove those lymph nodes that have the dye in it
what are the inguinal lymph nodes made out of
- Superficial inguinal lymph nodes
- Popliteal lymph nodes
- can be found within the femoral triangle
what do the inguinal lymph nodes drain
- lymph from lower limb and genetialia
what are the two groups of inguinal lymph nodes
vertical
horizontal
where is the vertical inguinal lymph node group and what does it drain
this lies along the termination of great saphenous vein – majority of the superficial lymphatics from the leg
where is the horizontal inguinal lymph node group and what does it drain
• Superficial lymphatics from anterior abdominal wall, the perineum, and the external genitalia (excl. testes)
- runs superficial to inguinal ligament
where are the deep inguinal lymph nodes
these are in the femoral canal
- there are 3 nodes there
- these also receive lymphatics from the deep structures of the leg
why are the ovaries and testes have there blood supply form the abdominal aorta
- The gonads develop in the abdomen and during fetal development descend in to the scortum or pelvis, dragging through the abdominal wall into the scrotum creates the scrotum
- As the testes and ovaries descend they take there blood supply with them, this is why they are form the abdominal aorta at the level of L2
- there lymph is also the same
where does lymph from the testes drain
- Lymph from the testes do no drain to inguinal lymph node, it travels back up with the testicular vein to drain with the para-aortic and lumbar lymph nodes whereas the scrotum drains into the superficial inguinal nodes
- Therefore testicular cancer and scrotum cancer will take different metastasise
deep lymph nodes are not….
palpable
where does lymph nodes from the abdomen lay
aorta, IVC, and iliac vessels
where does lymph from the internal and external iliac nodes drain
- Lymph from the internal and externa iliac nodes drains into the common iliac nodes and then the lumbar nodes
where does lymph from the GI tract drain
- Lymph from the GI tract drains into the pre-aortic lymph nodes (celiac, superior mesenteric, and inferior meseneteric nodes)
where does the lymph from the intestinal and right and left lumbar trunks drain
- Intestinal and right and left lumbar trunks drain to cisterna chyli (beginning of thoracic duct)
where does lymph from the heart drain
- parasternal nodes
- this then drains over the top of the heart into the right lymphatic duct
where does the subplerual plexus drain
- Subplerual plexus trains towards interlobular lymph vessels, then the interpulmonary nodes, then the bronchopulmonary nodes, then the inferior tracheobronchial nodes (receive lymph from the heart) then the superior tracheobronchial nodes, drain towards the Broncho mediastinal trunks, then the left and right venous drainage
what is the largest lymphoid organ
spleen
where is the spleen
located in the left hypochondrium, deep to the 9th-11th ribs.
- Just behind the mid axillary line
is the spleen intra or retro peritoneal
- Intraperitoneal
what is the spleen a site of
- lymphocyte proliferation
- RBC filtration, destruction and storage.
is the thymus a primary or secondary lymphoid organ
primary
where is the thymus located
- The thymus gland is a primary lymphoid organ, located in the superior mediastinum.
describe how the thymus develops
- After puberty the thymus gland undergoes progressive atrophy and is replaced by fat.
- Large in children and then it starts to artrophy (get smaller), only ever see fat during adult dissection
name the tonsils
- Palatine
- Lingual = posterior 1/3 of the tongue
- Pharyngeal (called adenoids if enlarged) – top of the nasopharynx
- Tubal tonsils – by the Eustachian tube
what do the tonsils do
Gather and remove some pathogens entering the pharynx in food or inhaled air
