Pressure and Flow in Arteries and Veins

Question 1

How is arterial pressure measured

Answer 1

Auscultation of Korotkoff sounds using sphygmomanometer and stethoscope

Question 2

Systolic pressure sound

Answer 2

Tapping

Question 3

Diastolic pressure sound

Answer 3

Silence

Question 4

Order of pressure sounds from high cuff pressure to lower

Answer 4

Silence, tapping, thumping, muffled, silence

Question 5

Disadvantages of measuring by Korotkoff sounds

Answer 5

Low accuracy
Discontinuous
Needs care

Question 6

Advantages of measuring by Korotkoff sounds

Answer 6

Non-invasive

Cheap

Question 7

Energy changes in aorta during systole and diastole

Answer 7

Absorb energy during systole and release energy during diastole

Question 8

Elastic arteries act as

Answer 8

Pressure reservoir

Question 9

Pressure wave of arteries is affected by

Answer 9

Stroke volume and velocity of ejection - rising phase
Elasticity of arteries - both
Total peripheral resistance - falling phase

Question 10

Normal arterial pressure

Answer 10

120/80mmHg

Question 11

Effect of age on arterial pressure

Answer 11

Increases

Question 12

Pressure from arteries to veins

Answer 12

Decreases

Question 13

Pressure drop in arteries

Answer 13

Small = 95 to 90 mmHg

Question 14

Pressure drop in arterioles

Answer 14

Large = 90 to 40 mmHg

Question 15

Pressure drop in veins

Answer 15

Small = 20 to 5 mmHg

Question 16

Velocity is related to

Answer 16

Total cross section

Question 17

Velocity is greatest in

Answer 17

Aorta and vena cava

Question 18

Velocity is lowest in

Answer 18

Capillaries

Question 19

Veins are

Answer 19

Distensible and collapsible

Question 20

External influences that affect flow in veins

Answer 20

Gravity
Skeletal muscle pump
Respiratory pump
Venomotor tone
Systemic filling pressure (main)

Question 21

Pressure in body due to gravity

Answer 21

Low pressure at head and high pressure at feet

Question 22

Gravity does not affect

Answer 22

Pressure from arteries to veins

Question 23

Gravity causes

Answer 23

Venous distension in legs and neck

Question 24

Effects of venous distension in legs

Answer 24

Decrease EDV, preload, stroke volume, cardiac output and main arterial pressure
Orthostatic (postural) hypotension

Question 25

Venous collapse in neck can be used to

Answer 25

Estimate central venous pressure

Question 26

What causes jugular vein to collapse

Answer 26

Pressure outside vein being greater than pressure inside vein

Question 27

Skeletal muscle pump

Answer 27

Contracts around vein squashing the blood inside upwards towards heart as blood can’t flow backwards - increases venous return

Question 28

Things of significance to skeletal muscle pump

Answer 28

Rhythmic (good) vs static (bad) exercise
Heat
Deep vein thrombosis
Varicose veins (swollen)

Question 29

Respiratory pump

Answer 29

With each inhalation pressure in the thorax decreases which increases the pressure gradient resulting in more venous return

Question 30

Venomotor tone

Answer 30

State of contraction of the smooth muscle surrounding the venules and veins - mobilises capacitance

Question 31

Systemic filling pressure

Answer 31

Pressure created by ventricle and transmitted through vascular tree to the veins (usually 5mmHg)

Question 32

Clotting involves

Answer 32

Formation of platelet plug and fibrin clot

Question 33

How is fibrin made

Answer 33

Made from fibrinogen by the action of thrombin

Question 34

Blood flow is so slow in capillaries that it is in danger of

Answer 34

Clotting

Question 35

Effect of stopping blood from contacting collagen

Answer 35

No platelet aggregation

Question 36

Prostacyclin and NO

Answer 36

Inhibit platelet aggregation

Question 37

Tissue factor pathway inhibitor (TFPI)

Answer 37

Stops thrombin production

Question 38

Thrombomodulin

Answer 38

Binds to thrombin and inactivates it

Question 39

Heparin

Answer 39

Inactivates thrombin

Question 40

Plasminogen activator

Answer 40

Digests clot

Question 41

What exhibits anti-clotting mechanisms

Answer 41

Endothelium