Chapter 10 - Lymphatic pathophysiology

Question 1

Lymphatic system organis

Answer 1

1) lymph nodes 2) spleen 3) Peyer patches 4) thymus 5) nasopharyngeal tonsils 6) cellular elements: lymphocytes, macrophages

Question 2

Anatomic areas without lymphatic tissue

Answer 2

CNS Cortical bony skeleton

Question 3

Lymphatic drainage of the upper extremity and head and neck

Answer 3

1) independently 2) common supraclavicular cistern

Question 4

Flow of lymph from liver

Answer 4

Retrograde/countercurrent to portal blood joins lymph collectors before the origin of thoracic duct

Question 5

Lymphatic like apparatuses in eye and brain

Answer 5

Eye: aqueous humor canal of Schlemm (anterior champer) Brain: CSF/subarachnoid villus (pacchionian bodies)

Question 6

Virchow-Robin space

Answer 6

Glial element and non-endothelial-lined intracerebral perivascular space serve to transport interstitial fluid to nearby intracranial venous sinuses

Question 7

Embryologic development theories of lymphatics

Answer 7

1) Sabin: centrifugal theory - primary lymphatic plexus from central vein - growth progress centrifugally by sprouting towards periphery 2) Kampmeier: centripetal theory - lymphatic system arise independently from tissue mesenchyme in periphery - later joins central venous system

Question 8

Lymphatic walls vs blood vessel walls

Answer 8

1) thin walled 2) tortuous 3) wider lumen 4) irregular lumen 5) devoid of RBC

Question 9

Lymph capillary structural key points

Answer 9

1) lack basement membrane 2) anchoring filaments tether outer endothelium to interstitial fibrous fel matrix

Question 10

Terminal lymphatics

Answer 10

1) devoid of SMC 2) rich contractile protein actin in endothelial lining 3) intraluminal bicuspid valves

Question 11

Lymphagions

Answer 11

Distinct partition of lymph vessels of discrete contractile segments

Question 12

Lymph flow rate

Answer 12

1.5-2.5 L/24 hr

Question 13

Type of edematous fluid depending on cause

Answer 13

Transcapillary hydrostatic and osmotic gradient (Starling forces) –> edema = protein content < 1g/dl Lymph stasis –> lymph edema = high protein > 1.5 g/dl

Question 14

Haphazard forces of lymph propulsion

Answer 14

Breathing, sighing, yawning, muscular squeezing (alimentary peristalsis), transmitted arterial pulsations

Question 15

Circulatory dynamics of lymph, vein, artery

Answer 15

TABLE 10.1

Question 16

Regulation of lymphatic vasomotion

Answer 16

1) sympathomimetic agents 2) byproducts of arachidonic acid metabolism (thromboxane, prostaglandins) 3) neurogenic 4) temperature 5) paracrine, autocrine

Question 17

Lymphatic pump able to generate this pressure

Answer 17

30-50 mmHg

Question 18

Lymphatic pump during lymphatic obstruction

Answer 18

Fluid column becomes continuous and loses the pump effects skeletal muscles and external compression becomes the new pumping mechanism

Question 19

Pathogenesis of peripheral lymphedema

Answer 19

FIGURE 10.9

Question 20

Weibel-Palade bodies

Answer 20

storage depots for vWf

Question 21

Mechanisms that govern lymphangiogenesis

Answer 21

Stimulatory: VEGF-C, VEGF-D Inhibitory: angiopoietin-1-angiopoietin-2 yin-yang interaction

Question 22

Hemangiodysplasia/lymphangiodysplasia clinical examples

Answer 22

1) vascular birthmarks 2) capillary, cavernous hemangioma/lymphangioma/mixed angioma 3) angiomatosis (including benign-metastasizing lymphagioma) 4) histiocytoid hemangioma 5) malignant endovascular papillary angioendothelioma 6) epithelioid hemangioendotheliomatosis 7) kaposi sarcoma 8) kaposiform eruptions 9) lymphangiosarcoma

Question 23

Chylous vs nonchylous reflux

Answer 23

Chylous = lymph from intestine non-chylous = lymph from limbs and other non-intestinal sources

Question 24

Stewart-Treves syndrome

Answer 24

Aggressive vascular malignancy after mastectomy and irradiation for breast cancer