Lympathics Flashcards
What are the three components of the lymphatic system?
Lymph fluid, vessels and organized lymphatic tissues/organs (spleen, liver, thymus, tonsils, appendix, visceral lymphoid tissue, LNs)
What is the physiologic function of the lymphatic system?
Major role in numerous homeostatic mechanisms of the body
Immune, digestive, fluid balance, waste
Describe lymphatic development
Begins during 5th week of gestation
Significant presence by 20 weeks
Describe lymphoid tissue during development
Immature at birth
Increases until 6-9 years
At puberty immune system matures but lymphoid tissues slowly degrees until 15-16 years
What is the function of the lymphatic system?
Maintain fluid balance, tissue cleansing/purification defense and nutrition
Describe fluid balance
30 L of fluid move from capillaries to interstitial space each day
90% to venules; 10% to lymphatic system
1/2 of diffused plasma proteins re-enter system via lymph
When fluid overload occurs the lymphatic system helps prevent tissue damage by doing what?
Clearing the excess
Second/third spacing
Describe purification and cleansing
Lymph fluid bathes organs
Cleanses extracellular spaces of particulate matter, toxins, bacteria, cellular waste products and post injury biochemical by products
Fluid then travels via lymphatic vessels -> LN (acts as purifying filter)
Describe the defense function
Lymph fluid brings toxins, bacteria and viruses into contact with the organized lymph tissue (LNs)
Contain high concentrations of immune cells, Ag processing and presentation, maturation of the immune cells -> immunity
Free flow of lymph necessary for appropriate immune function
Describe the nutrition function of lymph
Fat absorption via chylomicrons
Too big to cross capillary intercellular junctions
Travel via lacteals -> larger lymph vessels -> thoracic duct -> venous system
Returns proteins to vasculature
Proteins then bind nutrients
What is lymph fluid?
Substances that leak out of the arterial capillaries into the interstitium get taken up by the lymphatic capillaries (fluids, proteins, electrolytes, and cells)
Immune cells, foreign Ags, bacteria and viruses, clotting factors, chylomicrons post prandial
Which tissues do not have lymphatic vessels?
Epidermis (including hair and nails), endomysium of muscle, cartilage and bone marrow
What is the pathway of lymphatic vessels?
Terminal lymphatics -> collecting vessels -> afferent lymph vessels -> LNs -> efferent lymph vessels -> lymphatic trunks -> thoracic or right lymphatic duct -> venous system
What are terminal lymphatics?
Lymph formation begins in the interstitial space of tissues with initial lymphatics/terminal lymphatic/lymph capillaries
Lined by leaky endothelium anchored to ECM by small filaments
-endothelial cells overlap creating one way valves; lack smooth muscle walls
Terminal lymphatic coalesce into collecting vessels
What are collecting vessels?
Consists primarily of chains of muscular units called lymphangions which posses two leaflet bicuspid valves (lymphatic hearts)
Contract regularly throughout the lymphatic system and moving lymph in peristaltic waves
Contain smooth muscle
Describe LNs
Dispersed along the course of lymph vessels
Two types - superficial (within subcutaneous tissue) or deep (beneath fascia, muscles, organs)
Function: filtration of lymph fluid, maturation of lymphocytes and phagocytosis of bacteria/cellular debris
What is the path of lymph flow through a LN?
Afferent lymphatic -> subscapular space -> outer cortex (B cells)-> deep cortex (T cells) -> medullary sinus -> efferent lymphatics
What are the 5 lymphatic trunks?
Lumbar, intestinal, bronchomediastinal, subclavian and jugular
What do lumbar trunks drain?
Lymph from lower limbs and pelvic organs
What do intestinal trunks drain?
Abdominal viscera
What do bronchomediastinal trunks drain?
Portions of thorax
What does the subclavian trunk drain?
Upper limbs
What does the jugular trunk drain?
Portions of neck and head
What are cisterna chyli?
Located at level of L1-2
Drains lymphatic trunks of the lower body
Gives rise to thoracic duct
Describe the thoracic duct
Origin: cisterna chyli as a dilation at L1-2 level
Termination: pierces Sibson’s fascia at superior inlet, U turns to empty into L subclavian and L internal jugular veins
What is the function of the thoracic duct?
Master lymph vessel and drains L head and neck, LUE, L thorax/abdomen, everything inferior to umbilicus, receives from lumbar lymphatics
Describe the right lymphatic duct
Origin: from the junction of R jugular and subclavian trunks (and occasionally the bronchomediastinal trunk)
Termination: empties at R subclavian/R internal jugular venous junction
What does the right lymphatic duct drain?
R head/neck, RUE, R thorax, heart and lungs (except LUL)
Describe locating/evaluating LNs
Size/shape/consistency/tenderness/mobility/color/warmth
Describe Virchow’s node
L supraclavicular
Indicates intra-thoracic or abdominal cancer
What do swollen epitrochlear nodes indicate?
Secondary syphilis
Describe the spleen
Beneath ribs 9-11 on the left
Normally not palpable
Largest single mass of lymphoid tissue
Pressure-sensitive (movement of diaphragm drives splenic fluid movement)
What are the functions of the spleen?
Destroy damaged/deformed RBCs
Synthesize immunoglobulins
Clear bacteria
Describe the liver
RUQ; palpable at R costal margin Pressure sensitive (movement of the diaphragm is important for the homeostatic movement of hepatic fluids)
What is the lymphatic function of the liver?
Half of body’s lymph is formed here
Clears bacteria
Gate keeper of the shared hepato-biliary-pancreatic venous and lymphatic drainage
Describe the thymus
Located at anterior mediastinum
Development: large in infancy and size peaks at 2 y/o; after puberty involuted and replaced by fatty tissues
What is the function of the thymus?
Maturation site for T cells
Little or no function in adult
Describe the tonsils
3 types and all located in posterior oropharynx
Palatine (lateral pharynx)
Lingual (posterior 1/3 tongue)
Pharyngeal (adenoids at nasopharyngeal border)
Most are not visible until 6-9 m/o; remain enlarged through childhood
What is the function of the tonsils?
Provide cells to influence and build immunity early in life
Non essential to adult immune function
Describe the appendix
At the proximal end of the cecum (LI)
Contains lymphoid pulp (lymphoid tissue atrophies with age)
Part of the GALT
What is GALT?
GI associated lymphoid tissue
Peyer’s patches in the ileum
Lacteals in the SI
Pulmonary lymphoid tissue scattered, filters toxins from lungs
Describe interstitial fluid pressure (Pif)
Normally -6.3 mmHg (negative pressure system)
Pressure >0 mmHg = lymphatic capillaries collapse, flow ceases
Causes include increased hydrostatic pressure, decreased plasma colloid osmotic pressure, increased capillary permeability
Smooth muscle contraction within walls of large lymph vessels -> pressure gradients -> peristalsis
Describe direct diaphragmatic pressure in the thoracic diaphragm
With each breath contraction increases the negative intrathoracic pressure which pulls fluid centrally
Also exerts a direct force on the cisterna chyli pushing fluid superiorly
Describe direct diaphragmatic pressure in the pelvic diaphragm
Synchronous with thoracic diaphragm
Helps move fluids from the lower extremities and pelvic to the thoracic duct
May be dysfunctional in dysmenorrhea, endometriosis, post labor and delivery, BPH, etc
Describe the sympathetic NS effects on lymph valves
Increased sympathetic tone —> tighter valves —> decreased lymph flow into the venous system
Describe the SNS effects on lymphatic smooth muscle
Increased sympathetic tone —> decreased peristalsis —> lymphatic congestion
What are the consequences of a poorly functioning lymphatic system?
Edema
Buildup of interstitial fluid (poor lymphatic flow, imbalance of Starling forces)
Increased edema —> continued increased interstitial pressure —> lymphatic vessels collapse —> more edema
What can cause increased arterial pressure?
HTN, drugs, increased blood volume
What can cause increased venous pressure?
CHF, valvular disease, venous obstruction, dysfunctional venous valves
What can cause decreased plasma osmotic pressure?
Cirrhosis, protein malnutrition (Kwashiorkor), DM
What can cause increased capillary permeability?
Infection, rattlesnake bite, trauma
What are the effects of edema?
Compression of local structures
-vascular (decreased delivery of O2, nutrients, meds or hormones)
-neuronal (decreased sensation, pain, or paresthesia)
-SOB if pulmonary; decreased LOC if cerebal)
Decreased tissue waste removal (i.e. lactic acid; pH of tissues chain goes and leads to pain)
Decreased pathogen clearance and immunity
Chronic states -> fibroblast recruitment and activation
What is lymphatic OMT?
A diverse group of techniques designed to remove impediments to lymphatic circulation and promote and augment flow of interstitial fluid and lymph
What is the purpose of lymphatic OMT?
To improve the functional capacity of the lymphatic system
Including the maintenance of body fluid balance purification and cleansing of tissues, enhancement of immune responses
Improve tissue nutrition
What are the goals of lymphatic OMT?
Balanced well functioning system in which no edema occurs
Remove impediments to lymphatic flow
Enhance mechanisms involved in respiratory circulatory homeostasis
Extrinsically augment the flow of the lymph and other immune system elements
Further mobilize lymphatic fluids from local tissues that need decongestant
What are the indications for lymphatic OMT?
Lymphatic congestion, manifested as edema, mild CHF, upper or lower respiratory infections, asthma, COPD, ligamentous sprains or muscular strains, acute somatic dysfunction or pregnancy
Chronic conditions should be approached with caution
What are the absolute contraindications for lymphatic OMT?
Anuria (need kidneys functioning to process the extra fluid return)
Necrotizing fasciitis (in the tx area)
Pt unable to tolerate tx
Pt refuses tx
What are the relative contraindications for lymphatic OMT?
Inability to tolerance excessive preload in CHF pt, COPD (thoracic pump with activation), acute asthma exacerbation, unstable cardiac conditions, untreated coagulopathies or pts on anticoagulants, cancer, fracture or crushed tissue, bacterial infections, chronic infections, diseased organ, pregnancy, circulatory disorders
What is the risk to benefit ratio?
Clinical judgment must be used in employing lymphatic techniques with particular attention to the pt’s diagnosis, clinical condition, and medical therapy
These factors influence choice of the appropriate technique, dose, duration and frequency of Tx
What are the principles of diagnosis from a lymphatic approach?
- Evaluate risk benefit ratio
- Evaluate fascial patterns of Zink (which describe fascial restriction patterns that causes restriction to lymphatic flow)
- Evaluate diaphragms/fascia including thoracic inlet for restrictions that may limit lymph drainage
- Evaluate for SD affecting any motion that would normally enhance lymph flow
- Evaluate tissue congestion (excess fluid in the interstitial tissues)
What is a compensatory pattern?
L/R/L/R
80% of healthy people
What is a uncommon compensatory pattern?
20% of healthy people
R/L/R/L
What are uncompensated patterns?
Usually symptomatic and a trauma is unusually involved
Ex. R/R/R/R
What are the transverse restrictors?
Tentorium cerebelli, thoracic inlet, thoracolumbar diaphragm, pelvic diaphragm
What are the transition zones of the spine?
OA, C1, C2
C7, T1
T12, L1
L5, sacrum
What is the sequence of generalized lymphatic tx?
- Open pathways to remove restrictions to flow (transverse myofascial restrictors - thoracic inlet, myofascial restrictors, broad fluid movement)
- Maximize diaphragmatic functions (abdominal and pelvic diaphragms)
- Increase pressure differentials or transmit motion (fluid pumps)
- Mobilize target tissue fluids (localized to specific somatic dysfunctions)
