Pressure & Flow In Arteries & Veins 2

Question 1

Describe the pressure difference between veins/venules the right atrium.

Answer 1

The pressure difference is about 15 to 20 mmHg, with low pressures in the veins/venules pushing blood back to the heart.

Question 2

Define distensibility in the context of veins and venules.

Answer 2

Distensibility refers to the ability of veins and venules to expand and collapse due to their thin walls.

Question 3

How does gravity influence blood pressure in the body when standing up?

Answer 3

Gravity increases pressure in the venule in the foot by about 80 mmHg, while decreasing pressure in the venule in the head by about 40 mmHg.

Question 4

Do changes in body position affect the driving pressures in the circulatory system?

Answer 4

No, changes in body position do not affect the pressure gradients pushing blood from arteries to veins/venules and back to the heart.

Question 5

Describe the impact of gravity on blood pressure in the venule in the head and foot when standing up.

Answer 5

The venule in the head experiences a decrease in pressure (about -30 mmHg), while the venule in the foot experiences an increase in pressure (about +90 mmHg).

Question 6

How does the distensibility of veins and venules make them susceptible to external influences?

Answer 6

The thin walls of veins and venules allow them to expand and collapse, making them sensitive to external factors like gravity that can affect blood flow.

Question 7

Describe the effect of gravity on blood flow whenaker stands up.

Answer 7

Gravity affects both the venous and arterial sides of blood flow, causing blood to pool in the legs and reducing blood return to the heart.

Question 8

Define postural hypotension.

Answer 8

Postural hypotension, also known as orthostatic hypotension, refers to a decrease in blood pressure that occurs when a person stands up.

Question 9

How does increased pressure in the veins and venules of the legs affect blood flow back to the heart?

Answer 9

The increased pressure causes veins and venules to distend, leading to blood pooling in the legs and reduced blood return to the heart.

Question 10

Do arteries or veins and venules experience more pressure-related changes when a person stands up?

Answer 10

Veins and venules experience more pressure-related changes due to their thin walls, leading to distension and blood pooling.

Question 11

Describe the impact of postural hypotension on cardiac output.

Answer 11

Postural hypotension can lead to a decrease in stroke volume, which in turn reduces cardiac output and mean arterial pressure.

Question 12

How does postural hypotension affect tissue perfusion?

Answer 12

Excessive postural hypotension can lead to inadequate perfusion of tissues and organs, potentially causing symptoms like light-headedness and fainting.

Question 13

Describe the concept of orthostatic collapse in veins and venules.

Answer 13

Orthostatic collapse occurs when negative pressure causes veins and venules in the head to collapse, often not visible but can move up the neck with increased central venous pressure.

Question 14

What can a raised internal jugular vein indicate in a person like Ronaldo?

Answer 14

A raised internal jugular vein can indicate a raised central venous pressure, often due to physiological reasons like stress or increased thoracic pressure.

Question 15

Define central venous pressure and its significance in clinical settings.

Answer 15

Central venous pressure is the pressure in the vena cava near the right atrium of the heart, used as an estimate of blood volume and heart function in clinical assessments.

Question 16

How does the skeletal muscle pump affect pressure and flow in veins?

Answer 16

The skeletal muscle pump aids in venous return by contracting muscles around veins, helping to push blood back towards the heart.

Question 17

Describe the relationship between central venous pressure and the visibility of jugular venous distention.

Answer 17

As central venous pressure rises, the point of collapse in the veins moves higher up the neck, making jugular venous distention more visible.

Question 18

What can a raised jugular venous pressure indicate in clinical practice?

Answer 18

A raised jugular venous pressure can be a sign of various diseases, including right-sided heart failure, and is commonly assessed by clinicians as part of diagnostic evaluations.

Question 19

Describe the role of skeletal muscle in aiding blood circulation in the legs.

Answer 19

Skeletal muscle contractions squeeze on veins and venules, pushing blood in both directions and increasing venous return.

Question 20

How do valves within veins and venules prevent backflow of blood?

Answer 20

Valves within veins and venules close to prevent backflow, ensuring blood moves towards the heart.

Question 21

Define deep vein thrombosis (DVT) and its risk factors.

Answer 21

DVT is the formation of blood clots in deep veins, often caused by prolonged immobility such as hospital stays or long flights.

Question 22

What is the purpose of wearing flight socks or DVT stockings in preventing DVT?

Answer 22

They compress leg vessels, aiding in pushing blood back to the heart more efficiently and reducing the risk of clot formation.

Question 23

Describe the respiratory pump and its impact on venous return.

Answer 23

The respiratory pump involves diaphragm movement creating pressure changes, pushing blood back to the heart and increasing venous return.

Question 24

How does faster and deeper breathing affect blood circulation during exercise?

Answer 24

Increased breathing rate and depth enhance blood flow back to the heart, crucial during high heart rates to counter decreased filling time.