Chapter 16 Vascular Physiology Flashcards
(140 cards)
What surround veins and drain interstitial fluid?
lymphatic ducts
What drain into thoracic duct?
lower extremities and left thorax
What drain into right lymphatic duct?
head, neck, right thorax
What is the presentation of SVC Superior Venous Cava Syndrome?
swollen head and neck
unilateral ankle swelling?
DVT until ruled otherwise
bilateral ankle swelling?
right-sided heart failure
What lab value goes up with clots in body?
D-dimer
What radiographic test done for DVT?
Doppler ultrasound
What is Virchow’s triad?
cause of clotting: hypercoagulability, stasis, endothelial injury
Tx for DVT?
heparin
1 Cause venous clots?
stasis
1 cause arterial clots?
endothelial injury
Tx arterial clots
aspirin
Homan’s sign
calf pain upon dorsiflexion
How do veins constrict before arteries?
vessel constriction via norepinephrine (main neurotransmitter of ANS); NE has more affinity for alpha 1 receptors; veins have more alpha 1 receptors
When body loses volume, which is first to constrict, veins or arteries?
veins! always first before arteries
Poor perfusion of skin signs
- poor capillary refill
- cool extremities
- mottled appearance (lentigo reticularis)
Which vessels have greatest surface area and greatest diffusion?
capillaries
Explain Fick’s equation
In capillaries there is hydrostatic pressure pushing out of vessel and oncotic pressure pulling water and proteins into the capillary while the interstitium surrounding the capillary has hydrostatic pressure pushing fluids into capillaries and oncotic pressure pulling fluids out of the capillaries. There is usually a balance, but if the balance is interrupted (i.e. low albumin in the blood), the oncotic pressure inside will be less than the oncotic pressure in intersitium and proteins and fluid will be pulled more into the interstitium ; that is edema.
Which second messengers work in the veins?
veins, alpha 1 receptors, 2nd messenger IP3/DAG, causing constriction
Which second messengers work in the arteries?
beta 2, cAMP, causing dilation
plasma proteins usually don’t leak out of vessels, why not?
heparan sulfate provides a negative charge in the BM that repel negatively charged plasma proteins
What is transudate?
transudate is effusion that is mostly water; due to CHF, renal failure or hypothyroidism
What is exudate?
exudate is effusion that is mostly protein ( greater than 0.5 protein or LDH greater than 0.6 ) caused by purulent, granulomatous, caseous infections; always pathological