Venous Hemodynamics

Question 1

how much blood is in veins

Answer 1

2/3

Question 2

two different pressures effecting the vein shape are

Answer 2

intramural (internal)
interstitial (external)

Question 3

compliance permits increase in the blood volume without a significant increase in the _____

Answer 3

venous pressure

Question 4

veins are less ___ than arteries but are more ___

Answer 4

elastic
compliant

Question 5

veins have _____ resistance to blood flow when in the supine position due to _____

Answer 5

little
reduced effect of gravity

Question 6

the pressure difference from the post capillary vein and heart is ____

Answer 6

low

Question 7

venous return to the heart is assisted by (4)

Answer 7

cardiac cycle
respiration
muscles
valves

Question 8

2 periods of heart cycle increase venous flow

Answer 8

opening of tricuspid valve (more volume as can enter RV)
ventricular systole (pulls TV annulus down created more volume in RA for blood)

Question 9

when the TV opens there is more ___ in the heart, _____ the pressure

Answer 9

volume
dropping

Question 10

ASVD

Answer 10

atria contracts
ventricular systole (increased atrial V)
decreased flow as atria is filled
opening of TV

Question 11

venous flow affected by movement of diaphragm is referred to as ______

Answer 11

respirophasicity

Question 12

Valsalva maneuver increases pressure where (compared to diaphragm)

Answer 12

above and below diaphragm

Question 13

inspiration = intra-abdominal pressures

Answer 13

increase

Question 14

expiration = intra-thoracic pressures

Answer 14

increase

Question 15

inspiration = IVC

Answer 15

collapses

Question 16

inspiration = LE venous return

Answer 16

decrease (more pressure in abdomen)

Question 17

inspiration = UE venous return

Answer 17

increases (less intra-thoracic pressure)

Question 18

when can respiration effects be diminsed

Answer 18

when in supine position/with shallow breather/standing

Question 19

contraction of voluntary muscles (ex.calf) results in _____ venous pressure by interrupting the ______ column of blood

Answer 19

decreased
hydrostatic

Question 20

at rest, with no muscle activity, the veins act as _____

Answer 20

reservoirs for blood collection

Question 21

muscle contraction = venous flow in the deep and sup veins is _____ the heart
muscle relaxation = small amount of flow occurs in the _____, from the sup to the deep veins

Answer 21

toward
perforators

Question 22

calf pump: contraction of the ____ and ___ muscles are the most efficient

Answer 22

gastrocnemius
soleus

Question 23

calf capacitance high generate a pressure of about ___ mmHg/contraction

Answer 23

200

Question 24

in a single contraction of a calf muscle, ____% of the venous volume is ejected

Answer 24

40-60

Question 25

venous valves prevent

Answer 25

retrograde flow

Question 26

venous valves are _____ (bi/tricuspid) and arise from the ____ layer

Answer 26

bicuspid intimal

Question 27

vales in perforating veins direct flow from the ______ to the ____

Answer 27

superficial deep veins

Question 28

at the valve site, the vein ___ slightly at the sinus and ____ with increased pressure

Answer 28

dilates expands

Question 29

what is a frequent site of thrombi due to stagnant flow in a vein

Answer 29

at the sinus of valves

Question 30

_____ or _______ can impede the flow of blood back to the heart from the lower extremities

Answer 30

gravity hydrostatic pressure

Question 31

for every 12 inches of vertical distance below the heart, there are _____ of pressure

Answer 31

22mmHg

Question 32

hydrostatic pressure is defined by the ...

Answer 32

weight of a column of blood at a given point

Question 33

hydrostatic pressure is relative to the _______ pressure of zero

Answer 33

right atrial

Question 34

anything above the heart has _____ hydrostatic pressure

Answer 34

negative

Question 35

when supine, the hydrostatic pressure is ______ (about _____)

Answer 35

negligible 10-15mmHg

Question 36

when standing, the ankle hydrostatic pressure rises to around ______ and the leg veins ____ to accept the blood pooling

Answer 36

110mmHg dilate

Question 37

during activity, the blood is continuously ejected by muscle contractions, _____ the hydrostatic pressure. (walking hydrostatic pressure is about ____)

Answer 37

reducing 25mmHg

Question 38

transmural pressure determines

Answer 38

the cross-sectional shape of a vein

Question 39

transmural pressure is the difference between _____ and _____ pressures

Answer 39

intraluminal interstitial

Question 40

intraluminal pressure is the pressure _____

Answer 40

within the vein wall

Question 41

______ pressure is the pressure within the vein walls

Answer 41

intraluminal

Question 42

interstitial pressure is the pressure _____

Answer 42

exerted from outside the vein by surrounding tissue and fluid

Question 43

_____ pressure is the pressure exerted from outside the vein by surrounding tissue and fluid

Answer 43

interstitial

Question 44

what happens to the vein with low transmural pressure

Answer 44

the vein wall collapses and becomes elliptical in shape

Question 45

what happens to the vein with high transmural pressure

Answer 45

the vein becomes circular and may even distend at higher venous pressures

Question 46

respirophasic antegrade flow is opposite in upper and lower extremities due to the changes in the ______ and ______ pressure

Answer 46

intrathoracic intra-abdominal

Question 47

breathing in in lower extremities = flow ___ breathing in in upper extremities = flow ____

Answer 47

decreases increases

Question 48

central veins are veins near what

Answer 48

the heart

Question 49

what happens to upper and lower extremity veins when performing the Valsalva maneuver

Answer 49

increased thoracic and abdominal pressure = increases pressure in both upper/lower extremity veins = flow stops or diminish in both

Question 50

release of breath after Valsalva maneuver will _____ or ____ flow in both the upper and lower extremities

Answer 50

increase augment

Question 51

what is an abnormal response of flow during Valsalva maneuver

Answer 51

reverse of flow

Question 52

Valsalva maneuver should not be performed in patients with ____

Answer 52

heart disease

Question 53

3 abnormal waveforms

Answer 53

continuos pulsatile reflux

Question 54

continuos flow is when there is a lack of _____ usually as a result of a more ____ _____ from a ____ or _____

Answer 54

respirophasicity proximal obstruction clot extrinsic mass

Question 55

pulsatile flow is when the _______ is reflected into vessels further from the heart because of increased ______ pressure related to a heart condition

Answer 55

heart beat central venous

Question 56

retrograde flow is a result of ______ or _____.

Answer 56

valve incompetence venous distention

Question 57

a small amount of retrograde flow is _____, but if prolonged it represents venous _____

Answer 57

normal insufficiency