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
what is the valsalva maneuver?
when the patient takes a deep breath & bears down against a closed glottis
what is the result of the valsalva maneuver?
increased intra-ABD pressure –> stops or slows venous flow in LE
if venous flow increases during the valsalva maneuver, venous incompetence may be possible if the reflux continues for ____
> 1 sec
what is hydrostatic pressure?
the weight of a column of blood extending from heart to the point where it’s measured
what is the hydrostatic pressure of a supine individual?
10 mmHg
what is the hydrostatic pressure of a walking individual?
25 mmHg
what is the hydrostatic pressure of a standing individual?
80 mmHg
function of hydrostatic pressure in the arterial system?
it takes blood from the heart to the toes
what condition can occur as a result of standing in one spot for too long?
edema
what is edema?
the accumulation of excess fluid in intercellular spaces
what is venomotor tone?
the capacity for contraction of the smooth muscle in the tunica media
what part of the nervous system controls venomotor tone?
sympathetic nervous system
venomotor tone compensates for ___ problems
circulatory
how does venomotor tone compensate for circulatory problems?
it can force blood out of veins and into circulation or part of the body where blood is needed (ex: hemorrhage of organ)
what are 5 normal doppler findings for LEV?
- spontaneous flow
- phasicity
- augmentation
- competency of valves
- nonpulsatility
what is phasicity?
change in doppler patterns with respiration
what is augmentation?
with distal compression, there should be a rush of blood superiorly
after augmentation, the doppler waveform crosses the baseline. what may you interpret from this?
there is an incompetent valve superior to where you are augmenting
veins along the center of the body may take on some ____ due to outside. arterial forces
pulsatility
4 classifications of the venous system?
- deep veins
- superficial veins
- perforators
- venous sinuses
where are venous sinuses located?
between muscles
what are the two superficial veins of the lower extremity?
- greater saphenous vein
- lesser/smaller saphenous vein
location of the GSV
starts at the dorsum of foot –> travels anterior to medial malleolus –> continues medially –> unites with CFV @ SFJ
location of the SSV
posterior part of the calf –> ascends back of calf to join popliteal vein at SPJ
what are perforating veins?
veins that form channels of communication bw superficial and deep veins
function of perforator valves?
ensure unidirectional flow
incompetent valves in perforators may lead to __ __ __
venous stasis ulcers
what are venous sinuses and why are they important?
they are spaces that allow blood to pool in the calf muscles. they are important in the calf muscle pump in that the blood pooled here is brought back to PTvv and peroneal vv when. the calf muscle pump contracts
what are the calf muscle veins?
- gastrocnemius vein/gastrocs
- soleal veins
where does the gastrocs drain to?
popliteal vein
where do the soleal veins drain to?
PT vv & peroneal vv
how many valves are in the GSV?
10-12
how many valves are in the LSV?
6-12
how many valves are in the perforators?
1 each
how many valves are in the popliteal vein?
1-3
how many valves are in the SFV?
1-3
how many valves are in the CFV?
1
how many valves are in the CIV?
0
how many valves are in the IIV?
0
how often are valves present in the EIV?
25% of the time
how many valves are inn the IJV?
1
