Chapter 23-Venous hemodynamics

Question 1

What is the primary function of the venous system?

Answer 1

Return blood to the heart ; serves as a reservoir for blood

Question 2

What are The four main components for effective venous return to the heart?

Answer 2

1 – central pump
2- pressure gradient
3- peripheral venous pump
4- Competent venous valves

Question 3

What are the two main types of pressure in the venous system?

Answer 3

Dynamic pressure and hydrostatic pressure

Question 4

What is hydrostatic pressure?

Answer 4

The weight of the column of blood from the heart to any given spot in the body

Question 5

What drives blood through the Venous system?

Answer 5

The contraction of the heart

Question 6

What type of vessel has the Biggest pressure drop?

On Test

Answer 6

Arterioles

Resistive vessels!

Question 7

What a patient is supine, there is little to no hydrostatic pressure,

True or false

Answer 7

True

Question 8

When you are sleeping supine on your back, what is the hydrostatic pressure in the right atrium?

Answer 8

0 mm/hg

Question 9

When you are sleeping supine on your back , what is the hydrostatic pressure in the leg?

Answer 9

8 mmhg

Question 10

The hydrostatic pressure at the ankle of a normal height person standing is approximately _______ mm/hg

Answer 10

100

Question 11

If a patient is standing up and has their right arm above their head what is the hydrostatic pressure above the right atrium

Answer 11

-50 mm/hg

Question 12

Veins collapsed at what hydrostatic pressure?

Answer 12

0 mm/hg

Question 13

What is the Valsalva maneuver And what is it used for?

Answer 13

To check for insufficient valves

Patient takes a deep breath in and bears down. This increases intrathoracic and intraabdominal pressure dropping ALL venous flow

Question 14

Inspiration ____ the diaphragm and expiration ______ the diaphragm

lowers/Raises

Answer 14

Inspiration lowers the diaphragm which decreases the infra-thoracic pressure and increase abdominal pressure

Expiration raises the diaphragm, increases intra-thoracic pressure and decrease intra-abdominal pressure

Question 15

When you breath in, this _____ the venous return to lower extremity but ___ return to upper

Decrease / increase

Answer 15

When you breath in, this DECREASES the venous return to lower extremity but INCREASE return to upper

Decrease / increase

Question 16

When you breath out (expiration), this _____ the venous return to lower extremity but ___ return to upper

Decrease / increase

Answer 16

When you breath out (expiration), this INCREASES the venous return to lower extremity but DECREASES return to upper

Decrease / increase

Question 17

What is the most important Peripheral pump in the body

Answer 17

A calf muscle pump

Helps propel blood upward

Question 18

When is the calf muscle pump activated?

Answer 18

With walking

Question 19

Explain the process of the calf muscle contraction…

Answer 19

1- The muscles contract which squeezes deep veins
2-blood flows to heart in both superficial and deep system
3- valves prevent backwards flow
4-perforator valves are closed

Question 20

Explain the calf muscle pump process…

Answer 20

1- Deep veins decompress and expand back
2- blood is drawn from superficial to deep veins through the perforators
3-blood is sucked from capillaries and veins through the calf
4- upstream valves are closed, reducing local venous pressure.

Question 21

Explain the process of an ineffective calf muscle pump

Answer 21

1- blood flows from deep to superficial veins thru the incompetent perforators
2- blood flows distally to foot
3-Inefficient circular flow of blood
4- venous pooling and venous hypertension when walking.

Question 22

Venous valves are one way valves that direct flow inward and downward.

True or false

Answer 22

FALSE

Valves direct flow inward and upward

Question 23

An ineffective muscle pump results in the inability for the pump to do what it’s supposed to. This results in?

Answer 23

poor muscle contraction

The purpose of the muscle pump is to propel the blood flow up and to closer to the heart. It can’t do that if it can’t contract

Question 24

Cardiac output equals venous return

True or false

Answer 24

True

Question 25

Ambulatory venous hypertension can be caused by??

Answer 25

ineffective calf muscle

Question 26

Veins are very COMPLIANT vessels, able to accomodate large changes in volume within a small change of pressure or time

Answer 26

TRUE

Question 27

A distended vein has ____ transmural pressure whereas a flattened vein has ___ transmural pressure

Answer 27

Distended vein has high pressure

Flattened vein has lower transmural pressure

Question 28

A distended vein will offer___ resistance than a flattened vein

Lower-higher?

Answer 28

Lower resitance

Question 29

When the heart contracts, this creates _____ pressure

Answer 29

dynamic pressure

Question 30

What is the formula for calculating hydrostatic pressure?

Answer 30

P x G x H = hydostatic pressure

P = gravity of blood
G- acceleration of gravity
h- distance from heart/height

Question 31

Without activation of the muscle pumps, dynamic pressure is inadequate to return blood from the limb to the heart. What will result from this?

Answer 31

venous hypertension

Question 32

What are a few reasons why someone would have an ineffective muscle pump

Answer 32

Patient doesnt walk, fused ankle, hemiparesis.

Having an ineffective muscle pump decreases ejection of blood, which allows reflux to occur.

Question 33

What is transmural pressure?

Answer 33

the pressure difference between the outside of the vessel (tissue pressure versus within the vessel.