Circulatory - Pt 3 Big Picture

Question 1

What structure prevents the blood from pooling to the periphery during expiraton?

Answer 1

Venous Valves

Question 2

What happens to the alveolus and pulmonary capillaries during pulmonary edema?

Why is this detrimental?

Answer 2

• Pulmonary edema involves the swelling of the interstitial fluid of the pulmonary system. This causes the alveolus and pulmonary capillaries to spread further apart thatn normally.
• This is bad because these tissues normally exchange gases through diffusion, which only works across short distances.

Question 3

1. What does TPR stand for? What is another name for it?
2. T/F - the arteries are the major source of resistance in this system?
3. Depends on the arrangement of blood vessels: [] and []

Answer 3

1. Total Peripheral Resistance; Systemic Vascular Resistance (SVR)
2. False - the arterioles would be correct.
3. series and paralle.

Question 4

What are the 2 types of Hypertension?

What is the difference between the 2?

Which one predominates in the population?

Answer 4

1. Primary Hypertension, Secondary Hypertension
2. Primary = the cause is unknown; Secondary = we know what causes the hypertension
3. Primary = 90-95% of patients.

Question 5

T/F

Hyperoxia is a serious consequence of pulmonary edema, and it is often a cause of death in critically ill patients?

Answer 5

FALSE

Hypoxia is a serious consequence of pulmonary edem.

Question 6

What are 2 indicators of High Pulmonary Wedge Pressure?

Answer 6

1. Abnormallly high filtration pressure at pulmonary capillaries
2. Left Heart Failure

Question 7

Right heart failure would be a symptom of [] [] [] []

Left heat failure would be a symptom of [] [] [] []

Answer 7

High Central Venous Pressure

High Pulmonary Wedge Pressure

Question 8

T/F

In a parallel arrangement of capillaries, the overal resistance of the capillary system will be closest in value to the smallest individual resistance in the system?

Answer 8

True

Question 9

A [] [] [] [] can occur due to an increase in the circulating blood volume or right hear failure…

Answer 9

High central venous pressure

Question 10

What is the “Respiratory Pump?”

Answer 10

The action of inspiration increases venous return to the heart.

Inspiration –> Decreased thoracic pressure –> Decrease CVP –> increase venous return

Question 11

What could be telling characteristics of high CVP?

Answer 11

Excessive BV

Right Heart failure

Question 12

Consistent Hypertension - >[]/[] mmHg

Answer 12

140/90 mmHg

Question 13

[] [] prevent the backward flow of blood through the veins of the body

Answer 13

Venous Valves

Question 14

What 3 factors effect cardiac output?

Answer 14

Preload

Contractility

Afterload

Question 15

How does Acute Respiratory Distress Syndrome lead to pulmonary edema?

Answer 15

• Any damage to the lungs can lead to pulmonary edema
• The lung capillaries would become leaky, spilling proteins into the interstitial. This proteins would increase the interstitial fluid colloid osmotic pressure…pulling more fluids into the interstial.

Question 16

Filling:

1. how much blood is able to pass back into the [] side of the heart
2. This is referred to as [] return

Answer 16

1. right
2. venous

Question 17

What are 3 major causes of pulmonary Edema?

Answer 17

High CVP

High Pulmonary Wedge Pressure

Lung Inflammation or Injury

Question 18

What are the 3 causes of Hypertension we covered? Why do these cause hypertension?

Answer 18

1. Excess of Fluid
   
   1. Increase in BV increases pressure
2. Alteration in the Renin-Angiotensin-Aldosterone Hormone Pathway
   
   1. controls the amount of sodium exreted in the urine
3. Stress
   
   1. ​resets the baroreceptors allowing a higher tolerance to BP values.

Question 19

What is the main factor attributing to Systemic Vascular Resistance (SVR)?

Answer 19

Arteriole Resistance

*Remember SVR = TPR

Question 20

What would happen to capillary pressure and upstream arterial pressure if you were to put a hypothetical “kink” in the arterioles?

Answer 20

• A kink would be like vasoconstriction of the arterioles
• Capillary pressure would decrease, because less BV
• Upstream arterial pressure would increase due to the back up of BV

Question 21

One of the main factors affecting the afterload of the heart is the [] of the elastic arteries and their ability to [] druing ventricular ejection….

Answer 21

compliance

“stretch”

Question 22

Run-through:

1. how much blood is able to pass through the [] and enter the [] capillaries
2. Largely controlled by [] [] []
   
   1. This opposes the [] of blood through the blood vessels

Answer 22

1. circulation; sytemic
2. Total Peripheral Resistance (TPR)
   
   1. flow

Question 23

What are the 2 “ways” for Ca2+ to affect contractility, in the heart?

Answer 23

1. Binds to troponin C and allows actin/myosin to bind
2. Binds to Calmodulin –> activate MLCK –> Phosphorylates MLC —> increased contractility

Question 24

We know the standard CO equation (SV x HR)…what other CO equation did we learn?

Answer 24

CO = MAP/TPR

Question 25

Cardiac Emptying:

1. how much blood is leaving the [] over a period of time
2. Measured as []

Answer 25

1. heart
2. Cardiac Output

Question 26

What 3 mechanisms assist Venous Return?

Answer 26

Venous Valves

Skeletal Muscle Pumps

Respiratory Pump

Question 27

T/F

In Series arranged capillary beds, the blood vessel with the smalles resistance will have the larges effect on the overall resistance of the system?

Answer 27

FALSE

It would be the the blood vessel with the largest resistance that would effect the entire system, because the blood would eventually have to flow through that highly resistant vessel since everything is in a series.

Question 28

1. How do you calculate the total resistance of a “series” and “parallel” capillary bed (equations)?
2. What type of capillary bed is found around most organs?

Answer 28

• Series = R_total = R₁ + R₂ + R₃…
• Parallel = 1/R_total = 1/R₁ + 1/R₂ + 1/R₃….

Parallel capillaries are found around most organs

Question 29

What are the 3 main organs with the smallest individual resistance?

Answer 29

Kidneys

Splanchinic beds (Intestine, GI etc)

Skeletal Muscle

Question 30

T/F

Cardiac Output directly influences the filling stage of the circulatory system?

Answer 30

FALSE

CVP and HR directly effect the “filling stage”

Question 31

What is normally the 1st treatment for pulmonary edema?

Answer 31

Diuretics, to decrease BV

Question 32

What are the normal values in a patient for the following:

CO

MAP

TPR

Answer 32

CO = 5 L/min

MAP = 100 mmHg

TPR = .02 PRU ((mmHg/(mL/min))

Question 33

[] [] determines the preload of the heart

Answer 33

Venous Return.

Question 34

In regards to the big picture circulatory system what are 3 main areas of concern?

1. Emptying
2. Closing
3. Run-through
4. Filling

Answer 34

Emptying

Run-through

Filling

Question 35

T/F

The TPR of the kidney, splanchnic beds, and skeletal muscles is one of the main factors affecting the “filling” of the blood through the systemic circulation?

Answer 35

FALSE

These TPR’s would affect the “Run-Through” of the blood through the sytemic circuit.

Question 36

1. CVP - [] pressure for the right side of the heart.
2. Usually around [] - [] mmHg
3. [] [] determines filling time

Answer 36

1. CVP - Filling pressure for the right side of the heart
2. 3-8 mmHg
3. Heart Rate determines filling time.

Question 37

T/F

An increase in CVP and an Increase in pulmonary capillary pressure could be indicative of pulmonary edema

Answer 37

TRUE

Both would be characteristic of pulmonary edema.