Lymphatics Flashcards
What three things make up the lymphatic system?
Lymph nodes, lymph fluid, drainage vessels
How is tissue fluid formed
High hydrostatic pressure in the capillary (lower oncotic) pushes fluid into the interstitium. High oncotic pressure in the interstitium (lower hydrostatic) pushes fluid back into capillary venule. Remaining tissue fluid -> lymph capillary
Net filtration not equal to net reabsorption (leakage of some smaller proteins, bacteria, debris etc into interstitium)
What is lymph made of?
Tissue fluid, small proteins, lipids, damages cells, bacteria, cancer cells
How much lymph does the body produce daily?
3-4L
Define what the lymphatic system does.
Continuous removal of remaining tissue fluid from EC space back to circulation. Route for spread of infection and malignancy
What are the 3 main roles of the lymph system?
Remove excess fluid from interstitium, return leaked small proteins and fluid to capillaries, immune defect- surveillance and phagocytic barrier
How many nodes must lymph pass through?
At least one
What two features make flow one directional?
Passive constriction- as get bigger run alongside pulsating arteries.
Intrinsic constriction- intrinsic ability to contract as start to fill with fluid (SM cells in larger vessels)
What are the two main lymphatic ducts everything drains into? Where do these drain?
R lymphatic duct and thoracic duct (L). Drain into subclavian
What does the R lymphatic duct drains?
R side of face, R arm, R hemithroax
What does the throacic duct drain?
L side of face, L hemithroax, abdomen and rest of body
Why does lymph not drain into arteries?
High pressure c.f veins that are low- draining low pressure to low pressure
What is lymphoedema?
Abnormal collection of protein rich fluid -> tissue swelling due to compromised lymp system. Non-pitting oedema. Chronic condition
What are the causes of lympoedema?
- Removed/enlarged nodes
- Infections (parasitic)
- Damage e.g cancer treatments
- Lack of limb movement- muscle constriction for movement of lymph
- Congenital- Milroy’s syndrome
What are the three main lymphoid organs?
Spleen, thymus, tonsils
What is the structure of a lymph node? Size? What do they contain?
CT, tough fibrous outer capsule, reticular CT indies (candy floss). Microscopic ->2.5cm. Collection of B and T lymphocytes
What are the two causes of swollen lymph nodes and the characteristics of each?
Infection (tender, mobile) e.g HIV, TB.
Malignancy (hard, matted, non-tender)
Where do regional nodes drain?
Into terminal nodes
800 lymph nodes in the body, how many in the H and N?
300
What are sup (regional) and deep (terminal) lymph nodes separated by?
Investing layer of deep cervical fascia
Name the sup lymph nodes
Submental, submandibular, pre-auricular, post-auricular, occipital, superficial cervical
What is Walderyer’s Ring and what does it consist of?
Collection of lymph nodes surrounding sup pharynx. Pharyngeal tonsils (adenoids), 2 palatine, 2 lingual
What are the 3 deep cervical lymph nodes? Which is most commonly enlarged, why?
Jugular-digastric, jugular-omohyoid, suprclavicular. Jugular-digastric- drains palatine tonsil- tonsillitis. (Also drains oral cavity, post 1/3 tongue, pharynx and larynx
What is the importance of the L suprclavicular node?
Virchow’s node- pancoast apical lung tumour.
What does the submandibular node drain?
Most of face, upper lip and teeth, lat lower lip, ant nasal cavity, middle tongue, submandibular and sublingual glands
What does the submental node drain?
Lower lip and teeth, ant chin, tip of tongue, floor of mouth
What do sup cervical lymph nodes drains?
Skin of neck
What does the occipital node drains?
Occipital area of neck and scalp
What does the pre auricular node drain?
Scalp, ant ear, parotid gland
What does the post auricular node drain?
Scalp, post ear, ear canal
Which tonsil is enlarged in tonsillitis?
Palatine
