Lecture 2 Resp Flashcards
bronchiole arteries come from what place of the heart
left ventricle
what part of the aorta do bronchiole arteries arise
descending thoracic aorta
what lung circulation system is high flow low pressure
pumonary (pumonary arteries proper)
what circulation system is low flow high pressure
systemic (bronchiole arteries)
bronchiole arteries deliver what type of blood to where in the lungs
to thicker lung tissue with non gas exchange areas
pumonary artery has what two physical features to reduce resistance and increase compliance and distensibility
thinner wall, larger lumen
main pulmonary artery and its branches have a larger diameter than systemic….true or false
true
what is the normal blood volume in the lungs
450ml……10% of total body fluid
right ventricle and pulmonary arteries are typically what pressure together
25mmhg
pulmonary vein and left atrium average at what pressure
2mmhg
pulmonary capillaries average at what pressure normally
7mmhg
what two pathologies of the heart can increase normal blood volume as high as 900ml?
- left sided heart failure
2. mitral valve stenosis or regurgitation
what phenomenon occurs in blood vessels of poorly oxygenated lung areas?
vasoconstriction (shunting towards more useful areas of ventilation)
What zone has no blood flow, where the alveolar pressure is higher than pulmonary pressure?
zone 1
a zone 1 situation can be induced by what 3 pathologies?
- severe blood loss
- breathing against positive pressure
- Right sided heart failure
(also a PE)
What type of blood flow is zone 2?
intermittent flow during quiet respiration
What type of blood flow is zone 3?
continuous flow (typically lower down toward the bases of the lungs)
Blood flow to lungs can increase 4-7 fold during exercise, and is achieved by what 3 mechanisms?
- capillary distensibility
- increased capillary numbers (local autoregulation opens up)
- increase in pulmonary artery pressure
below 8mmhg in the left atria, backup does not occur in what part of the lungs?
pulmonary artery pressure
if the pressure of the left atria exceeds 8mmhg, what is the relationship between LAP and pulmonary artery pressure as well as pumonary capillary pressure?
is increases 1:1 (in step with each other)
Above what Left atrial pressure (mmhg) does pulmonary edema begin to develop?
30mmhg
In a person with Left sided heart failure, what could the pressure potentially rise between?
40-50mmHg
Pulmonary capillaries are a low pressure system, (7mmHg), but quickly move through pulmonary capillaries…by what autoregulatoin can make that speed even faster
local pre-capillary sphincters opening up in the pulmonary arteries dropping resistance and increasing flow
what is the only place we see a significant interstitial osmotic pressure in the body (14mmHg)
Pulmonary capillaries (due to leaky capillaries that let proteins out)
That pulmonary interstitium maintains a net -5 to -8 mmHg at all times, what would happen if this number became positive?
Then fluid would accumulate in the alveoli and could rupture
what is the main player in keeping the alveoli “dry”
lymphatics (net filtration +1)
what 2 cardiac pathologies increase hydrostatic pressure that contribute to pulmonary edema?
- Left sided heart failure
2. Mitral valve disease
what 3 pathologies concerned with the filtration coefficient (capillary level), cause damage to the pulmonary capillaries?
- Inflammation
- Infection
- Noxious Gasses
Diseases of what 2 organs can decrease reabsorption in pulmonary capillaries, and result in a decrease in production of plasma colloids (plasma colloid osmotic pressure)
- Liver Disease (underproduction of proteins)
2. Kidney Disease (dumping of proteins)
is acute or chronic pulmonary edema more damaging?
acute (less accomodation)
how much wiggle room “safety factor” in mmHg exists between normal pressure increases, and the pressure at which edema begins to occur acutely?
21mmHG (contributed by colloid differences)
What mechanism allows chronic pulmonary edema to be subclinical?
lymphatics (can allow upto 40mmHg in pulmonary capillaries w/o edema)
