Lymphatics Flashcards
Name 3 functions of the lymphatic system
1) Drain excess interstitial fluid
2) Transport dietary lipids from GI tract to blood
3) Protects against invasion through immune responses
How many litres of interstitial fluid circulates?
3
Where is most extracellular fluid reabsorbed
Capillaries
What are lymphatic vessels
Larger capillaries that drain into ducts in venous system
What is the function of lymph nodes
Filter the lymph along the way
Define lymphati filariasis
Failure of lymph to drain back into the venous system so vessels swell up
Main worldwide cause of lymphatic filariasis
Roundworm which is transmitted by a mosquito
Is pressure high or low in lymphatic system
Low
How is flow in the lymphatic system aided? (5)
- Milking action of skeletal muscle
- Valves to prevent backflow
- Pressure changes in thorax
- Lymph vessels close to arteries and arteries are pulsatile
- Smooth muscle in walls of trunks and ducts contracts
What lymphatic trunks drain the legs?
Right and left lumbar
What does the intestinal duct drain?
Intestines and liver into thoracic duct
Name the 9 lymphatic trunks
Intestine Right and left lumbar Right and left subclavian Right and left jugular Right and left bronchomediastinal
Where does the right lymphatic duct drain?
Junction of IVJ and subclavian vein (same as the left)
What does the right lymphatic duct drain
Right upper quadrant
RIde side of head,neck, thorax and right arm
What does the thoracic duct drain
Left side and rest of body
Where does the thoracic duct begin and end?
Begins at cisterna chyle in abdomen
Ends at left venous angle
How do lymph nodes filter lymph
Macrophages remove and destroy microorganisms and debris
How do lymph nodes activate the immune system
Lymphocytes strategically located to monitor for presence of antigens
How many lymph nodes are there in the body
600
What do superficial components drain
The skin
Where do cervical nodes drain
Above the clavicle
Where do axillary nodes drain
Between clavicle and umbilicus
Where do inguinal nodes drain
Below umbilicus
Where do vessels enter the superficial lymph nodes to drain the head and neck
Along the course of the external jugular vein (over sternocleidomastoid)
Where do you find the deep cervical nodes
Vertical chain along internal jugular vein
What do the efferent vessels of the deep cervical nodes form
Right jugular trunk
Which lymph nodes are palpabale
Superficial lymph nodes
Which of the axillary nodes are palpable
Central node
Where do humeral nodes come from
Arm
Which of the axillary nodes are most anterior
Pectoral
Where are subscapular nodes found
Under the scapula
What are sentinel lymph nodes
First nodes that tumour arrives at
In which 2 directions do the 2 groups of inguinal lymph nodes run
Horixonal- superficial to the inguinal ligament
Vertical- lie along termination of great saphenous vein
What vessels make up horizontal lymph nodes
Superficial lymphatics from anterior abdominal wall, perineum, and external genitalia exlucing testes
What vessels make up vertical lymph nodes
Majority of superficial lymphatic from legs
Where do efferents from superficial lymph nodes drain to
Deep inguinal nodes
Name the nodes responsible for deep drainage of the thorax
Interpulomonary nodes Superior trachebronchila nodes Inferior tracheobronchial nodes Interlobar lymph vessels Sub pleural plexus Paratrachael Bronchomediastinal trunks
Where do the lymphatics of the post abdominal wall lie?
Aorta, inferior vena cava, iliac vessels
Where do external and iliac ndoes drain to
Lumbar lymph nodes
What forms the lumbar trunk
Efferents from lumbar lymph nodes
Where do intestinal and right and left lumbar trunk drain to
Cisterna Chyle
What vessels come from the abdomen
Pre aortic lymph nodes
Intestinal lymph trunk
What is Trosiers’ sign?
Hardened lump in supraclavicular nodes- abdominal cancers may metastasise to left supraclavicular lymph nodes
How can lymph nodes differentiate between cancer and infection
Cancer= hard lymph ndoes Infection= tender lymph nodes
Is lymph node distribution the same or different in children and adults
Same
How does lymphoid tissue size change during childhood
Increases to twice adult mass between 6-9 years
Regresses to adult levels by puberty
Are tonsils larger and smaller in childhood?
Larger
How does lymph system change in older adults?
Number and size decreases with age
Some elements are lost (thyroid)
More fibrotic and fatty
Name all of the lymph nodes accessible to examination in head and neck (11)
Preauricular Postauricular Occipital Tonsillar Submandibular Submental Superiro anterior cervical Deep cervical Posterior cervical Supraclavicular Infraclavicular
Name all of the lymph nodes accesible to examination in the arm
Axillary nodes (anterior axillary/pectoral, lateral/ brachial, mid axillary/ central, posterior/ subscapular) Epitrochlear
Name all of the lymph nodes accessible to examination in the legs
Superficial superior inguinal
Superficial inferior inguinal
Popliteal (sometimes)
Do lymphoid organs filter lymph
No- just the lymph nodes do this
Do organs typically have afferent lymphatics, efferent lymphatic or both
Efferents
Functions of the spleen (5)
Site for lymphocyte proliferation Immune surveillance Cleanses blood Stores and releases breakdown products of RBC Erythrocyte production in foetus Stores platelets
How does the spleen drain the blood?
Extracts aged and defective blood cells and platelets
Macrophages remove debris and foreign matter
What does thymus secrete
Thymopoietin and thymosins
Descibe anatomical positioning of thymus
Inferior neck and superior thorax
Deep to the sternum
Name the 4 tonsils
Palatine
Lingual
Pharyngeal
Tubal
What are pharyngeal tonsils called if they’re enlarged
Adenoids
Functions of tonsils
Gather and remove some pathogens entering pharynx in food or inhaled air
Define payers patches
Large isolated clusters of lymphoid tissue located in wall of distal small intestine
Functions of peyers patches
- Destroy bacteria and prevent pathogens breaching intestinal wall
- Generate memory lymphocytes for long term immunity
