Pathogenesis of Dz

Question 1

What NT imbalance is associated with Asthma and HTN? And why?

Answer 1

Too much NE, not enough EPI.
DEC in cortisol (d/t too much DHEA).
Issues with Tyrosine/Dopamine and/or Tryptophan/Serotonin
Def. of B vitamins (B6, B12, folate, Vit. C, Cal/Mag)

Question 2

Difference in ventilation and perfusion for pink puffer vs. blue bloater? Who benefits more from low dose oxygen?

Answer 2

Pink Puffer: Ventilation > Perfusion
Alveolar well ventilated, poor perfusion d/t damaged alveoli from fibrosis (atherosclerotic endothelium)

Blue Bloater: Perfusion > Ventilation
Alveolar ventilation DEC d/t secretions/spasm leading to reflex vasoconstriction & DEC blood to area of poor perfusion

Blue bloater benefits from low dose oxygen

Question 3

Explain the Frank Starling Mechanism

Answer 3

Ability of heart to change force of contraction (via INC tension by INC resting mm length) & stroke volume in response to changes in venous return.

Question 4

CO (cardiac output) and what is Nml?

Answer 4

Amount of blood pumped by each ventricle per minute
CO = SV * HR
Nml = 5000 mL/min; 2.5-3.6 dL/min/m2 of body surface

Question 5

Stroke Volume (SV)

Answer 5

Related to afterload, preload, inotropy, relative synchronous contraction of all parts of ventricle

Question 6

Afterload

Answer 6

Ventricular systolic stress: tension/stress/pressure that ventricle must develop to open aortic/pulmonic valve

Question 7

Why might afterload INC?

Answer 7

aortic stenosis, emphysema, HTN, HOCM, ventricular systolic stress/tension, INC ventricle size

Question 8

Preload = EDV

Answer 8

End diastolic volume: return volume of blood to the heart

Question 9

Why might preload INC?

Answer 9

INC venous BP, INC atrial contractility d/t sympathetic stim, DEC HR (INC ventricular fill time), ventricular systolic failure (back up of blood into ventricle), INC ventricular afterload (DEC forward flow), outflow valve & inflow valve regurg.

Question 10

Inotropy

Answer 10

Velocity with which heart mm contracts, tension developed by mm

Question 11

Law of LaPlace

Answer 11

Tension in cylinder wall (ventricle) directly proportional to pressure supported by wall (L ventricular systolic pressure) & radius of cylinder (ventricular radius). Tension = (pressure * radius) / wall thickness

Question 12

Hypertrophy

Answer 12

INC in both size of individual mm cells & overall mm mass

Question 13

Dilatation

Answer 13

Chamber enlargement, ABN INC in size of cavities of heart, in response to volume overload (i.e. aortic/mitral regurg), compensatory INC in CO via Frank-Starling

Question 14

What might dilatation w/o volume overload be from?

Answer 14

ventricular failure

Question 15

Contractility

Answer 15

Intrinsic ability of heart mm fibers to shorten or develop mm tension indepdent of preload

Question 16

Ejection Fraction

Answer 16

Heart empties btwn 56-78% of volume in systole, stroke volume = 56-78% of EDV, ratio of stroke volume to EDV