Week 3

Question 1

The term meaning the study of blood flow characteristics is ______________

Answer 1

Hemodynamics

Question 2

How do veins prevent bidirectional flow? (7 ways)

Answer 2

1. Skeletal muscle contraction
2. Venous valves
3. Compliance
4. Respiratory function
5. pressure gradients
6. motor tone
7. cardiac function

Question 3

Define Venous Capacitance

Answer 3

Capacitance allows venous system to conform to varying blood volumes.
Veins are storage tanks of the body’s blood

Question 4

How much of our blood does the venous system store?

Answer 4

2/3

Question 5

What 2 factors contribute to the storing ability of veins?

Answer 5

1. Flexibility of vein walls

2. Vein pairing

Question 6

Define Venous Compliance

Answer 6

The ability of veins to expand, contract, and collapse

Question 7

T/F. Arteries are more elastic than veins.

Answer 7

TRUE. But veins are MORE COMPLIANT, therefore, they can expand and contract easier

Question 8

What is meant by veins being compliant?

Answer 8

they can expand and contract easier

Question 9

What is significant about Venous Resistance?

Answer 9

The ability of veins to change shape allows them to accommodate an increase of blood flow with resulting in increased pressure.

Question 10

A more circular shaped vein = _____________

Answer 10

less resistance to blood flow

Question 11

A more elliptical shaped vein = ______________

Answer 11

more resistance to blood flow

Question 12

Relation. Venous flow and pressure

Answer 12

inversely

Question 13

Relation. Venous flow and volume

Answer 13

inversely

Question 14

Define Transmural pressure

Answer 14

the difference between the pressure inside the vein and the pressure of the tissue outside the vein

Question 15

the force outside the vein walls is _____________

Answer 15

tissue pressure

Question 16

the force from inside the vein walls is ___________

Answer 16

intraluminal pressure

Question 17

What will a vein look like with a high transmural pressure?

Answer 17

circular. Increased intraluminal pressure and volume

Question 18

A vein that has a more dumbbell / elliptical shape has what?

Answer 18

a low transmural pressure

Question 19

When standing, the transmural pressure is ________; when supine, the transmural pressure is ________.

Answer 19

increases, low

Question 20

Define hydrostatic pressure

Answer 20

the pressure from gravity on a column of blood

Question 21

A major force that affects our venous system is ______________.

Answer 21

hydrostatic pressure

Question 22

Where does the hydrostatic pressure = 0?

Answer 22

the Right Atrium (reference point)

Question 23

Name 4 factors that affect hydrostatic pressure?

Answer 23

1. Body position (standing vs supine)
2. Height
3. The Heart
4. Resistance across arterioles

Question 24

The __________ the distance from the _________, the greater the force of gravity, and the greater the force of _________________.

Answer 24

further, heart, hydrostatic pressure

Question 25

Describe what happens during INSPIRATION and how it affects venous flow.

Answer 25

1. Diaphragm descends 2. Abdominal cavity pressure Increases / Chest pressure decreases 3. Abdominal blood volume decreases 4. IVC collapses due to increased abdominal pressure 5. Venous Flow from extremities is reduced

Question 26

Describe what happens during EXPIRATION and how it affects venous flow.

Answer 26

1. Diaphragm ascends 2. Chest pressure increases / Abdominal pressure decreases 3. Abdominal blood volume increases 4. Venous flow from the extremities is increased

Question 27

There is an increase in pressure in the leg causing the valves to shut during ____________.

Answer 27

Inspiration

Question 28

During expiration, there is a _____________ in pressure in the leg veins, causing the valves to _________.

Answer 28

decrease, open

Question 29

What is known as the peripheral heart? Why?

Answer 29

The calf muscle pump, because it helps venous blood return from the legs against hydrostatic pressure.

Question 30

What muscles are the power source of the calf muscle pump?

Answer 30

the gastrocnemius and the soleal

Question 31

The calf muscle pump generates _______ mmHg of pressure per contraction.

Answer 31

200

Question 32

Name three functions of the calf muscle pump.

Answer 32

1. lowers venous pressure 2. reduces venous volume in the legs 3. promotes venous return to the heart

Question 33

The number of valves __________ the closer you get to the heart.

Answer 33

decrease

Question 34

What is the pressure as the blood moves in to venules? a. 0 mmHg b. 15 mmHg c. 30 mmHg d. 90 mmHg

Answer 34

B. 15 mmHg

Question 35

How is lower extremity venous flow effected during inspiration?

Answer 35

Venous flow decreases

Question 36

How much of the venous volume should be ejected from the calf during a normal muscle contraction?

Answer 36

40 - 60%

Question 37

Repiratory variation in the lower extremities suggests:

Answer 37

Normal venous flow

Question 38

The pressure exerted from outside the vein on the vessel is know as __________.

Answer 38

Tissue pressure

Question 39

Ambulatory venous pressure is defined as ____________.

Answer 39

High venous pressure when standing

Question 40

Define flow.

Answer 40

the amount of liquid moving past a certain point at a given time

Question 41

Arm veins have ______ valves than leg veins.

Answer 41

less

Question 42

All fluids need a pressure _______ to flow.

Answer 42

gradient

Question 43

The diaphragm moves _________ during inspiration.

Answer 43

down

Question 44

Venous flow in the leg occurs with contraction of the ________ and _________ muscles of the calf.

Answer 44

Gastrocnemius, Soleus

Question 45

Vein walls _______ when standing.

Answer 45

expand

Question 46

When you take a deep breath in, the pressure in the intrathoracic cavity is __________ than the pressure in the abdominal cavity.

Answer 46

less

Question 47

Define Hemodynamics

Answer 47

the study of blood flow characteristics

Question 48

This allows venous system to conform to varying blood volumes.

Answer 48

Venous Capacitance

Question 49

The ability of veins to expand, contract, and collapse

Answer 49

Venous Compliance

Question 50

Define tissue pressure

Answer 50

the force outside the vein walls

Question 51

Define intraluminal pressure

Answer 51

the force from inside the vein walls

Question 52

the difference between the pressure inside the vein and the pressure of the tissue outside the vein

Answer 52

Transmural pressure