pulmonary circulation, pulmonary edema and pleural fluid

Question 1

What is the compliance of pulmonary vessels and what does a large compliance of pulmonary vessels alow

Answer 1

its 7ml/mm HG and its compensates for the stroke volume output

Question 2

what gives pulmonary arteries large compliance

Answer 2

they have more diameter, they are distensible which gives them a larger compliance

Question 3

bronchial vessels supplies to?

Answer 3

the supporting tissues of lungs, septa, connective tissues and bronchi

Question 4

the flow into the left atrium and the left ventricular output are about 1 to 2 percent greater than that
of the right ventricular output. why?

Answer 4

because the bronchial vessels and arterial blood enters into the left atrium after it supplies the supporting tissue

Question 5

lymphatics in the lungs drain into?

Answer 5

right thoracic lymph duct

Question 6

The systolic

pressure in the right ventricle of the normal human averages about

Answer 6

25 mm of hg

Question 7

the diastolic pressure averages

about in right ventricle

Answer 7

0-1 mm of hg

Question 8

the systolic pulmonary arterial pressure normally averages about

Answer 8

25 mm of hg

Question 9

the diastolic pulmonary arterial pressure normally averages about

Answer 9

8 mm of hg

Question 10

The mean pulmonary

capillary pressure,

Answer 10

7 mm of hg

Question 11

The blood volume of the lungs is about

Answer 11

450 mililiters

Question 12

how lungs compensate as a blood reservoir such as in hemorrhage

Answer 12

it shifts blood from the pulmonary circulation into the systemic circulation in case of blood loss

Question 13

what causes the blood to damn up in pulmonary circulation

Answer 13

Failure of
the left side of the heart or increased resistance to blood
flow through the mitral valve as a result of mitral stenosis
or mitral regurgitation causes blood to dam up in the
pulmonary circulation

Question 14

When the concentration of O2 in the air of

the alveoli decreases below normal, which is how much below normal and what happes?

Answer 14

<73mm hg

vasoconstriction AND increase vascular resistance

Question 15

low O2 concentration may

stimulate

Answer 15

• release of vasoconstrictors like endothelin and reactive o2 species
• inhibition of vasodilators such as nitric oxide

Question 16

hypoxia may directly induce

vasoconstriction by

Answer 16

yinhibition of oxygen-sensitive potassium ion channels in pulmonary vascular smooth muscle
cell membranes. With low partial pressures of oxygen,
these channels are blocked, leading to depolarization of
the cell membrane and activation of calcium channels,
causing influx of calcium ions. The rise of calcium concentration then causes constriction of small arteries and
arterioles

Question 17

how high pulmonary vascular resistance has good effect on distributing blood

Answer 17

That is, if some alveoli are poorly ventilated and have a low O2
concentration, the local vessels constrict. This constriction causes the blood to flow through other areas of the lungs that are better aerated, thus providing an automatic
control system for distributing blood flow to the pulmonary areas in proportion to their alveolar O2 pressures

Question 18

when the capillary in the alveolar wall close

Answer 18

when the alveolar pressure is high on the outside of the capillaries than inside

Question 19

what are zone 2 and zone 3 of pulmonary blood flow

Answer 19

zone2: intermittent
when the pulmonary arterial pressure is more than the alveolar air pressure (systolic pressure> alveolar air pressure)
zone3: continuous blood flow
when pulmonary cappilary pressure is more than alveolar air pressure.

Question 20

when would one expect zone 1 blood flow

Answer 20

when a person is breathing against positive air pressure the intra alveolar air pressure is greater than normal and systolic pressure is normal which expect zone 1 of blood flow
or after blood loss when pulmonary systolic pressure is very low

Question 21

During heavy exercise, blood flow through the lungs
may increase fourfold to sevenfold. This extra flow is
accommodated in the lungs in three ways:

Answer 21

(1) by increasing the number of open capillaries, sometimes as much
as threefold; (2) by distending all the capillaries and
increasing the rate of flow through each capillary more
than twofold; and (3) by increasing the pulmonary arterial
pressure

Question 22

what ability of lungs prevent pulmonary edema

Answer 22

its ability to compensate for blood flow without increasing the pulmonary pressure and conserves the energy at right side of the heart

Question 23

what happens when left atrial pressure rises above ….? (FILL THE BLANK TOO)

Answer 23

• above 7 mm hg
  it increases the workload on the right side of the heart, increases capillary pressure and when its above 30 mm hg it causes edema

Question 24

mean pulmonary atrerial pressure is

Answer 24

15mm of hg

Question 25

meant left atrial pressure

Answer 25

2 mm hg

Question 26

mean pulmonary cappilary pressure

Answer 26

7 mm hg

Question 27

The dynamics of fluid exchange across the lung capillary
membranes are qualitatively the same as for peripheral
tissues. However, quantitatively, there are important differences, as follows:

Answer 27

1. The pulmonary capillary pressure is low, about 7 mm Hg, in comparison with a considerably higher functional capillary pressure in the peripheral tissues of about 17 mm Hg.
2. The interstitial fluid pressure in the lung is slightly more negative than that in peripheral subcutaneous tissue.
3. The colloid osmotic pressure of the pulmonary interstitial fluid is about 14 mm Hg, in comparison with less than half this value in the peripheral tissues.
4. The alveolar walls are extremely thin, and the alveolar epithelium covering the alveolar surfaces is so weak that it can be ruptured by any positive pressure in the interstitial spaces greater than alveolar

Question 28

what causes the flow of fluid from pulmonary cappilaries into the interstitial spaces

Answer 28

the outwards forces are slightly higher than the inward forces +1 mm hg

Question 29

the Mechanism for Keeping the Alveoli “Dry.” What keeps the alveoli from filling with fluid under normal
conditions?

Answer 29

negative pressure in the interstitial
spaces, it is clear that whenever extra fluid appears in the alveoli, it will simply be sucked mechanically into the lung interstitium through the small openings between the alveolar epithelial cells.

Question 30

what causes pulmonary edema

Answer 30

• any thing that prevents the lymphatic function of the pulmonary system
• high rate of filtration through the pulmonary capillaries
• increasing the interstitial fluid pressure from negative to positive

Question 31

The most common causes of pulmonary edema are as

follows in lungs:

Answer 31

1. Left-sided heart failure or mitral valve disease, with consequent great increases in pulmonary venous pressure and pulmonary capillary pressure and flooding of the interstitial spaces and alveoli.
2. Damage to the pulmonary blood capillary membranes caused by infections such as pneumonia or by
   breathing noxious substances such as chlorine gas or sulfur dioxide gas. Each of these mechanisms causes
   rapid leakage of both plasma proteins and fluid out of the capillaries and into both the lung interstitial spaces and the alveoli.

Question 32

what should happen before significant pulmonary edema occurs

Answer 32

the pulmonary capillary pressure must rise to equal or colloid osmotic pressure of plasma in the capillaries before edema occurs

Question 33

n acute safety factor against

pulmonary edema explain

Answer 33

if someone’s colloid osmotic pressure of plasma in the capillaries is 28mm of hg so the pulmonary capillary pressure must rise from 7 mm hg to 28 to cause edema so the acute safety factor against pulmonary edema is 21 mm hg