LYMPHATIC SYSTEM Flashcards
What is the lymphatic system responsible for carrying back to blood?
Capillary ultrafiltrate fluid volume & escaped plasma proteins.
What type of diuresis is the lymphatic system based on?
Osmotic diuresis.
What are the four functions of the lymphatic system?
- Absorb macromolecules (proteins & FAs)
- Maintain fluid balance in tissue
- Fight infection
- Remove cell debris & waste products from extracellular spaces.
What happens if normal lymphatic transport mechanisms are disrupted?
Lymphedema (latent, acute, or chronic).
What are the other organs & tissues in the lymphatic system besides superficial & deep lymph vessels & nodes?
- Thymus
- Bone marrow
- Spleen
- Tonsils
- Peyer patches of small intestine.
True or False: Both superficial & deep lymph drainage is symmetric.
False (deep is asymmetric).
Where do right upper extremity & thoracic lymphotome drain into?
Right lymphatic duct.
Where do left upper extremity, left thoracic lymphotome, both lower extremities, external genital areas, & abdominal lymphotomes drain into?
Left subclavian.
True or False: 3/4 of total flow drains to the left subclavian vein.
True.
What enhances flow in trunks & ducts?
Respiratory efforts.
Which lymph vessels rely on interaction of oncotic & hydrostatic pressures, muscle contraction, arterial pulsation, & gentle movement of skin to absorb & transport lymph fluid?
Superficial lymph vessels.
Deeper lymph vessels are generally parallel to which system?
Venous system.
What are the smallest lymph vessels called?
Initial lymphatics or lymphatic capillaries.
What powers initial lymphs?
Variations in total tissue pressure caused by movement & muscular contraction.
What external pressures affect initial lymphs?
Stretch, gravity, & change in position.
What happens without changes in total tissue pressure?
Fluid will accumulate in interstitium, leading to edema.
What is the term for each segment of collecting lymphatic vessels between valves?
Lymphangion.
What do lymph valves prevent?
Backflow.
What increases the pumping actions of lymph valves?
- Extrinsic muscle contraction
- Autonomic stimulation
- Manual lymph drainage.
True or False: Collecting lymphs form a plexus with several connections between them.
False (does not form plexus, some connections).
Lymph trunks have a gradual increase in what?
Diameter size of collecting lymphatics.
True or False: Muscle in collecting lymph walls contract arrhythmically.
False.
What do smooth muscle cells around the endothelial cell layer of the lymph vessel network face?
Lumen of vessel.
How many times per minute does the lymph vessel network contract at rest on average?
5-10 times per minute.
What does the pressure inside the vessel reach if many lymphangions contract at once and outflow is obstructed?
100 mm Hg or more.
What does sustained high intravascular pressure lead to?
- Ineffective smooth muscle contraction
- Vessel failure.
What do lymph vessel network walls dilate to prevent closure to?
Valve flaps.
What does backflow of lymph distal to the site of obstruction cause?
Lymphedema.
Deep lymph vessels are embedded in what type of tissue?
Fatty tissue.
What are the four functions of lymph nodes?
- Filter to clean lymph of waste products & cell debris
- Adjust fluid concentration
- Produce lymphocytes & macrophages
- Destroy foreign bacteria, viruses, & cancer cells.
Why are lymph nodes often at the sites of obstruction in lymph dysfunction?
Nodes offer 100x normal resistance to flow of lymph within vessels themselves.
What is the term for separate territories of lymph?
Watersheds.
What are the smaller divisions in territories that designate areas specific to certain regional nodes called?
Lymphotomes.
What are the four trunk quadrants?
Left & right:
- Axillary territories
- Inguinal territories.
What are some characteristics of suspicious nodes?
- Changes in size (> 2 cm)
- Immobile
- Firm or hard
- Painless & enlarged.
What is lymphangitis?
Inflammation of lymph vessel.
What is lymphadenitis?
Inflammation of 1 or more lymph nodes.
What is lymphedema?
Increased amount of lymph fluid in soft tissues leading to swelling.
What is lymphadenopathy?
Enlargement of lymph nodes.
Lymphedema is accompanied by tissue ____________ secondary to chronic inflammation with prolonged swelling.
Fibrosis.
What are the stages of lymphedema?
0 (latent) - III (lymphostatic elephantiasis).
What do the following causes increase the risk for lymphedema?
- Individuals who undergo lumpectomy with ALND or SLND & radiation therapy
- Inguinal lymph node dissection to treat melanoma
- Prostate cancer after pelvic node dissection
- Gyne cancers
Lymphedema.
Which type of lymphedema are these etiologic factors associated with?
Primary lymphedema.
What is the most common cause of secondary lymphedema worldwide (not in the US)?
- Filariasis
- Parasitic worm introduced by mosquito bite in endemic region.
What is the most common cause of secondary lymphedema in the US?
Invasive procedures used in diagnosis & treatment of cancer.
What are some clinical manifestations of lymphedema?
- Full, heavy, tight sensation in affected body part
- Numbness, burning, aching, pain
- Decreased flexibility in hand, wrist, or ankle
- Loss of skin integrity.
Which type of lymphadenitis is characterized by enlarged, tender, warm, & reddened lymph nodes?
Acute lymphadenitis.
Which type of lymphadenitis is characterized by scarred lymph nodes with fibrous connective tissue replacement?
Chronic lymphadenitis.
What is the term for acute inflammation of subcutaneous lymphatic channels that occurs as a result of strep or staph entering a wound?
Cellulitis.
