Lymph Anatomy & Physiology Flashcards
1
Q
3 main functions of the lymphatic system
A
- lymphatic circulation
- immune system
- fat/fatty acid digestion
2
Q
Lymph circulatory system
A
- one way drainage
- transport proteins that are too large to re-enter venous capillaries
- loose junctions btw endothelial cells encourages gapping
- tiny filaments that anchor lymph vessels to surrounding connective tissue
3
Q
Immune support lymph organs (B and T lymphocytes and macrophages)
A
- lymph vessels and nodes
- thymus gland
- bone marrow
- spleen
- tonsils
- bowel/mucous membranes
- appendix
4
Q
Major lymph node collection sites
A
- colon
- axilla
- neck
- inguinal region
- bronchial region
5
Q
Lymph node functions
A
- antigen presentation
- immune cell recognition
- phagocytosis
6
Q
Lymph node sequence of events
A
- antigen enters lymph node through lymph vessel
- triggers inflammation and causes lymphocytes & macrophages to multiply in the lymph node causing swelling
- phagocytosis begins
- inflammation & increased WBCs cause lymph fluid to thicken
7
Q
Direction of flow in lymphatic circulation
A
- lymphatic capillaries
- lymph nodes
- lymph trunks
- lymph ducts
- internal jugular/subclavian veins (right lymphatic duct enter R subclavian vein and left thoracic duct enter L subclavian vein)
8
Q
What areas does the right lymphatic duct drain in the body
A
- right UE
- right side of trunk
- right side of face
9
Q
Describe lymph vessels
A
- located superficially in the skin, subcutaneous, and deep fascia
-parallel the venous system - thinner walls, more valves, & contain lymph nodes at designated points
10
Q
3 layers of lymph vessels
A
- Intima: one layer of endothelial cells
- Media: smooth muscles
- Adventitia: collagen
11
Q
What is lymph flow controlled by
A
- tissue pressure
- circulatory system is controlled by a central pump
12
Q
What is lymph flow facilitated by
A
- intermittent skeletal muscle activity
- lymphangion vessel contractions
- an extensive system of one way valves
13
Q
Lymphangions
A
- region btw valves
- smooth muscle stretch reflexes sensing when it fills with lymph fluid
- contracts 6-12 times at rest and increases 10 fold with aerobic activity
14
Q
Other physiological pressures that influence lymph flow
A
- arterial pulsations
- postural changes
- respiratory pressure changes
- scar tissue
- body mass/skin folds
15
Q
Transport capacity
A
- amount of lymph volume that can be transported in a given period of time
16
Q
Contraction regulation
A
- sympathetic NS regulates contraction in the lymphangion
- pain and stress can decrease the activity of the lymph flow in the lymphangion
17
Q
High output failure
A
- lymphatic load is too great to transport the fluid from the interstitium
- caused by anything that causes swelling (ex. an injury)
18
Q
Low output failure
A
- lymphatic system has difficulty transporting a minimal amount of high protein fluid from the interstitium due to damage in the lymph vessels or lymph nodes
19
Q
Combined insufficiency
A
- combination of a high output failure & a low output failure
- high output failure due to infection, trauma, or surgery
- low output failure due to previous injury to lymph vessels or modes (ex. radiation therapy)
20
Q
Lymphedema
A
- low output failure
- consists of protein rich fluid & low grade inflammation with reactive fibrosis as a result of altered/damaged lymph transport capacity
21
Q
What is the only diagnostic imaging to diagnose lymphedema
A
- lymphoscintigraphy
22
Q
Congenital abnormality of development of the lymphatics
A
- hypoplasia: reduced # of lymph collectors & decreased diameter of lymph vessels
- hyperplasia: increased # of collectors
- aplasia: absence of lymph system components
- kinmoth syndrome: inguinal lymph node fibrosis
23
Q
Milroy disease, lymphedema praecox, and lymphedema tarda
A
- Milroy: observed at birth due to gene mutation
- Praecox: developed before 35
- Tarda: developed after age 35
24
Q
Prevalence for primary lymphedema
A
- females 2x more than males
- LE 3x more than UE
- Bilateral 2x more than unilateral
25
Secondary lymphedema
- damage to an otherwise normal lymphatic system
26
Risk factors for secondary lymphedema
- invasive procedures
- regional lymph node dissection
- radiation therapy
- scar tissue
- burns
- skin folds
27
Symptoms of lymphedema
- tightness/heaviness/discomfort in the area
- not usually painful
- swelling & decrease in skin mobility
- loss of strength or flexibility in a limb
- variations in skin temperature and/or color
28
Lipedema
- painful "fluid in the fat" disorder
- feet are not involved
29
Stewart-Treves syndrome
- rare angiosarcoma that develops in people with long standing lymphedema
- usually people have a history of breast cancer that was treated with radical mastectomy
30
Stage 0/Latent lymphedema
- lymph transport is impaired but there is no clinical evidence of swelling
- may last months to years
- symptoms of progression from stage 0 to stage 1: sensation of heaviness, fatigue, ache, or pain in the limb at risk
31
Stage 1 lymphedema
- chronic inflammatory response to the excessive protein in the interstitium
- pittting on pressure
- reverses with elevation
- progression from stage 1 to stage 2: subcutaneous tissues begin to fibrose due to protein buildup
32
Stage 2 lymphedema
- non-pitting
- does not reduce on elevation of the limb
- clinical fibrosis is present: skin is thick & rigid
- clear, sticky lymph fluid may ooze from pores
33
Stage 3 lymphedema/lymphostatic elephantiasis
- severe non-pitting
- large lobular folds
- fibrotic edema with atrophic skin changes such as thickened, leathery, keratitis skin, skin folds with tissue flaps, papillomas (warty like overgrowth)
34
Volume differences for functional severity
- Minimal: < 3cm difference and < 20% increase in limb volume
- Moderate: 3-5cm difference and 20-40% increase in volume
- Severe: > 5cm difference, positive Stemmers sign, and > 40% increase in volume
