Class 14: LEV Anatomy Flashcards
where are paired veins located in the lower extremity?
below the knee
deep venous system runs with the ___
arteries
where are superficial veins?
just under the skin
what are the veins that transport blood from the superficial to deep venous system called?
perforators
where in the lower extremities are more valves located?
closer to the feet
where do the common iliac veins join to form the IVC?
at the 5th lumbar vertebrae
the CFV comes from the IIV. T/F?
false
3 layers of venous wall?
tunica externa/adventitia
tunica media
tunica intima
which venous wall contains the vasa vasorum?
tunica adventitia
the tunica media of the venous wall is thinner than the arterial venous wall. T/F?
true
which are larger: veins or arteries?
veins
where do veins transport blood to?
back to the heart
veins are not compliant or distensible. T/F?
false – veins are highly compliant and distensible
veins have ___ pressure and ___ flow
low pressure, steady flow
what is the pressure in the veins compared to arteries?
there is a 20 mmHg difference in venous pressure compared to arterial pressure
4 shapes veins can be
- collapsed
- elliptical
- round
- dumbell
veins will be circular with ____ intraluminal pressure & ____ transmural pressure
increased
what is transmural pressure?
the difference between intraluminal & interstitial pressures
6 factors influencing venous return
- pressure gradient
- calf muscle pump
- valves
- respiration
- gravity
- vasoconstriction
2 other names for calf muscle pump?
little heart or venous heart
how does the calf muscle pump work?
it’s the contraction of the soleal and gastrocnemius muscles –> the pressure squeezes the blood forward
what is the shape of venous valves?
bicuspid
what layer of the veins are the valves a part of?
tunica intima
function of venous valves?
to prevent the backflow of blood
chronic ___ ____ may cause increased venous pressure
venous insufficiency/incompetent valves
how does respiration influence venous return in the LE
inspiration decreases venous flow in LE by increasing intra-abdominal pressure and decreasing intrathoracic pressure.
expiration increases venous flow in the LE by decreasing intra-abdominal pressure and increasing intrathoracic pressure