Pressure & flow in arteries & veins

Question 1

what is systolic pressure

Answer 1

it is the blood pressure when the heart is contracting

Question 2

what is systolic pressure specifically

Answer 2

the maximum arterial pressure during contraction of the left ventricle of the heart

Question 3

what is systole

Answer 3

the time at which ventricular contraction occurs

Question 4

what is diastolic pressure

Answer 4

it is specifically the minimum arterial pressure during the relaxation and dilation of the ventricles of the heart when the ventricle fill with blood

Question 5

what is pulse pressure

Answer 5

the difference between the systolic pressure and diastolic pressure

Question 6

what is pulse pressure measured in

Answer 6

mmHg

millimetres of mercury

Question 7

what does the pulse pressure represent

Answer 7

the force that the heart generates each time it contracts

Question 8

what is resting normal blood pressure

Answer 8

120/80mmHg, then the pulse pressure is 40mmHg

Question 9

what are Korotkoff sounds

Answer 9

arterial sounds heard though a stethoscope applied to the brachial artery distal to the cuff of a sphygmomanometer that change with varying cuff pressure

Question 10

what are Korotkoff sounds used for

Answer 10

determination of systolic and diastolic blood pressure

Question 11

what is hearing kormokoff sounds used as a common method for

Answer 11

noninvasive measurement of blood pressure in adults

Question 12

when is systolic blood pressure taken in relation to listening to korotkoff sounds

Answer 12

it is taken to be the pressure at which the first korotkoff sound is heard

Question 13

what makes up the vascular tree

Answer 13

arteries, arterioles, capillaries, venules and veins

Question 14

during the ejection phase what are the ventricles doing

Answer 14

contracting and pushing the blood out of the aortic valve

Question 15

describe the maintenance of pressure in arteries during the ejection phase

Answer 15

• push of blood out the aortic valve
• elastic walls of the aorta swell
• the swelling absorbs energy

Question 16

describe pressure in relation to the aorta

Answer 16

the aorta is an elastic artery
it damps down pressure
it controls pressure varyingly
this artery stops pressure getting too high or too low during diastole

Question 17

describe the maintenance of pressure in arteries during the relaxation phase

Answer 17

ventricles fill
the aortic valve is shut
the elastic energy is released from the walls of the aorta
maintaining the pressure

Question 18

in systemic circulation, what is the pressure wave affected by

Answer 18

stroke volume
velocity of ejection
elasticity of arteries
total peripheral resistance

Question 19

what is normal arterial pressure equal to

Answer 19

120/80mmHg

Question 20

interns of systemic circulation, what is the relationship of pressure and the vascular tree

Answer 20

pressure falls throughout the vascular tree

Question 21

what is pressure like through arteries

Answer 21

small pressure, low pressure

Question 22

what is pressure like through the arterioles

Answer 22

pressure is greater as arterioles are resistance vessels

Question 23

what is pressure like through capillaries

Answer 23

pressure is already low when blood gets to the capillaries - this is good as capillaries are thin-walled

Question 24

what is the systemic filling pressure

Answer 24

the very small pressure gradient that is left to push blood back through the veins

Question 25

what must total flow through your arteries, arterioles, capillaries, venules and veins be

Answer 25

it must all be the same

Question 26

what must the velocity of blood flow be through arteries, arterioles, capillaries, venules and veins

Answer 26

it is not all the same | velocity changes in each of the vessels

Question 27

what does the velocity in blood vessels relate to

Answer 27

the total cross sectional area of the particular blood vessel

Question 28

what does the velocity of blood flow depend on

Answer 28

the total cross sectional area of vessels

Question 29

describe total cross sectional area of the aorta

Answer 29

the aorta has a big diameter however there is only one aorta therefore the total cross sectional area is very small

Question 30

describe the total cross sectional area of capillary vessels

Answer 30

capillaries have small diameters, tiny in fact however there are thousands of capillaries which makes the total cross sectional area large 5000cm squared in fact

Question 31

describe blood flow through different total cross sectional areas

Answer 31

blood flow is fastest through the aorta due to the aorta having a small total cross sectional area blood flow is the slowest through the capillaries as the capillary vessels have the greatest total cross sectional area

Question 32

when does blood flow speed up again following it flowing through the capillaries

Answer 32

blood flow speeds up again going through the vena cava

Question 33

describe the pressure in veins

Answer 33

the pressure is low there is a small pressure gradient pushing the blood from the venules to the veins to the heart 20mmHg

Question 34

describe why the pressure in the veins may be so small

Answer 34

because these vessels are thin walled, there is not much smooth muscle, therefore these vessels collapse and are distensible very easily, these vessels are very susceptible to external influences

Question 35

state 5 things that affect venous pressure and venous return

Answer 35

``` gravity the skeletal muscle pump the respiratory pump venomotor tone systemic filling pressure ```

Question 36

does gravity affect the driving pressure from arteries to the veins

Answer 36

no

Question 37

does gravity make it more difficult for the blood to get back to the heart

Answer 37

no

Question 38

what can gravity cause

Answer 38

venous distention in the legs and venous collapse in the neck

Question 39

describe the result of gravity causing venous retention in the legs

Answer 39

``` reduced end diastolic volume decreased preload weaker contraction reduced stroke volume reduced cardiac output reduced mean arterial pressure result in orthostatic hypotension ```

Question 40

what is the result in gravity causing venous collapse in the neck

Answer 40

your central venous pressure can resultantly be estimated

Question 41

what is the skeletal muscle pump

Answer 41

it is a collection of skeletal muscles that aid the heart in circulation of the blood

Question 42

what is the importance of the skeletal muscle pump

Answer 42

it is important in increasing venous return to the heart | it plays an important role in arterial blood flow

Question 43

what is the role of peripheral vein valves

Answer 43

they stop the blood going backwards, pushing the blood towards the heart

Question 44

describe the effect on veins from the constriction of skeletal muscles

Answer 44

the squeeze capacitance of blood that is in the veins in the skeletal muscle back towards the heart, increasing venous return

Question 45

what does the skeletal muscle pump's effect on the veins have significance for

Answer 45

rhythmic exercise static exercise hot guardsmen - not using pump deep vein thrombosis varicose veins

Question 46

how is sustained contraction of skeletal muscle not good

Answer 46

it stops blood getting through the veins back to the heart

Question 47

describe how the respiratory pump effects the blood flow through veins

Answer 47

``` the faster you breathe in the deeper you breathe in the more you encourage venous return the more blood back to the heart increase in your end diastolic volume think about exercise ``` the respiratory pump is one of the things that maintains end diastolic volume

Question 48

describe how inhalation effects venous return

Answer 48

inspirations tends to draw blood back to the heart | inhalation increases venous return

Question 49

describe how venomotor tone effects the blood flow through veins

Answer 49

activation of smooth muscle around the veins squeezes the blood towards the heart venomotor tone mobiles the capacitance of veins the squeeze of the smooth muscle pushes the blood back to the heart, increasing end diastolic volume

Question 50

what is venomotor tone

Answer 50

is is a state of contraction of the smooth muscle surrounding the venules and veins

Question 51

describe venomotor tone

Answer 51

it is the degree of tension in the muscle coat of a vein that determines the shape of the vein

Question 52

what is result of changes in venomotor tone

Answer 52

the capacity of veins is altered

Question 53

state 3 things that help maintain/increase end diastolic volume

Answer 53

the skeletal muscle pump the respiratory pump venomotor tone

Question 54

what is the major thing that is driving blood through your venules and veins to the heart?

Answer 54

your systemic filling pressure

Question 55

what is arterial pressure measured by

Answer 55

Korotkoff sounds

Question 56

what can estimated by jugular collapse

Answer 56

your central venous pressure

Question 57

what does gravity cause

Answer 57

collapse of the jugular vein