Lymphatics Flashcards
Who first described the lymphatics system and when?
Olaf Rudbeck (Sweden) in 1653
When did AT Still emphasize that diagnosis of the fascia and treatment of the lymphatic system was vital for maintaining health and treating disease?
1874
Who and when was Applied Anatomy of the Lymphatics published?
1922: Frederic Millard DO
When does lymphatic development begin? Significant?
5th week of gestation; 20 weeks
From which structures do lymphatic structures arise?
Mesoderm - lymph vessels, lymph nodes, spleen, myeloid tissue
Endoderm - thymus and parts of tonsils
When does lymphoid tissue increase until?
puberty
What happens to the immune system in geriatrics?
declines, may not mount a fever
What are the anatomic components of the lymph system?
tissues/organs: spleen, liver, thymus, tonsils, appendix, visceral lymphoid tissue, lymph nodes
lymph fluid
lymphatic vessels
What are the physiological functions of the lymphatic system?
immune
digestive - nutrition
fluid imbalance
waste
Spleen: location, characteristics, function
location: beneath ribs 9-11 on left, next to diaphragm
normally not palpable
characteristics: largest single mass of lymphoid tissue, fluid movement driven by diaphragm movement
functions: destroy damaged/deformed RBCs, synthesize Igs, clear bacteria
Liver: location, characteristics, function
location: RUQ; palpable at R costal margin
characteristics: movement of diaphragm important for movement of fluids
function: half body’s lymph formed here, clears bacteria, “gate keeper” of shared hepato-billary pancreatic venous and lymphatic drainage
Thymus: location, characteristics, function
location: anterior mediastinum
characteristics: large in infancy and peaks at 2 yo, involutes after puberty and replaced by fatty tissue
function: maturation of t cells, little or no function in adults
Tonsils: location, characteristics, function
location: 3 types in posterior oropharynx: palantine (lateral pharynx), lingual (posterior 1/3 tongue), and pharyngeal (adenoids at nasopharyngeal border)
characteristics: not visible until 6-9 mo, remain enlarged through childhood
function: provide cells to influence and build immunity early in life, nonessential to adult immune function
Appendix: location, characteristics, function
location: proximal end of the cecum (large intestine)
characteristics: contains lymphoid pulp, atrophies with age
function: part of GALT
What are examples of GALT?
Peyer’s patches (ileum), lacteals (lymphatic capillaries of small bowel), appendix (cecum)
What is lymph fluid and what is is made of?
Substances that leak out of the arterial capillaries into the interstitium get taken up by lymphatic capillaries;
immune cells, foreign antigens, bacteria and viruses, clotting factors, chylomicrons post-prandial
How much fluid moves from capillaries to interstitial space each day? to where?
30 L; 90% to capillaries, 10% to lymphatic system
What does the lymphatic system help prevent?
third spacing
How much drainage through the thoracic duct is associated with respiration?
35-60%
What tissues do not have lymphatic vessels?
epidermis, endomysium, cartilage, bone marrow
What do the lymph channels begin as? What are they composed of?
The lymph channels begin as blind endothelial tubes or capillaries composed of a single layer of leaky squamous epithelium that is supported by anchoring filaments.
What are the path of the lymphatic vessels?
lymphatic capillaries, collecting lymphatics, afferent, efferent, thoracic duct or R lymphatic duct, venous system
What are lymphagions?
chains of muscular units that possess two-leaflet bicuspid valves that contract regularly throughout the system and move lymph along in peristaltic waves
What is the afferent lymphatics?
channel that delivers lymph to the node from the peripheral tissues on the side opposite the hilum
