Primer 12 Flashcards
How is phenylalanine converted to epinephrine?
1- phenylalanine –> Tyrosine (Phe hydroxylase)
2-Tyrosine –> DOPA (Tyrosine Hydroxylase)
3- DOPA –> Dopamine (dopa decarboxylase, requires B6)
4. DOPA –> NE
5. NE –> Epi
*Note: Carvidopa blocks dopa decarboxylase
List eight indirection cholinergic agonists and their uses
Also: What does it mean to be an “indirect” cholinergic agonist?
- Cholinergic agonists block AchE
- neostigmine; reverses NMJ block post op
- edrophonium: diagnoses MG
- pyridostigmine: treats MG
- physostigmine: reverses artropine poisioning
- rivastigmine, galantamine, donepezil- Alzheimers
Outline five steps of fetal circulation:
Important points
- know where oxygenated and deoxygenated blood mix in fetal circulation
- know three ways blood may get to the aorta from the right atrium
- know where CO2/ O2 are transferred
- maternal placenta –> fetal liver via umbilical vein (which carries oxygenated blood)
- oxygenated blood from u. vein mixes with deoxygenated blood from extremities at ductus venosus
- mixed blood enters right atrium
- Blood can take three routes to get to the aorta
a. RA –> LA (via Foramen Ovale) –> LV –> aorta
b. RA –> RV –> PA –> lungs –> LA –> LV –> aorta
c. RA –> RV –> PA –> aorta (via the DA) - aorta –> systemic circulation –> placenta via umbilical artery (*umbilical artery allows transfer of CO2/O2)
Describe the murmur of aortic stenosis
- timing
- sound
- location
- maneuver effects
- systolic
- shortly after S1 due to isovolumetric contraction
- ejection click + crescendo/decrescendo
- best heart at left 2-3rd ICS lateral to sternum
- Unchanged with hand grip maneuver, worsened by squatting, improved with exhalation
Clinical signs & symptoms assc with aortic stenosis
- weak pulses (pulsus parvus et tardus)
- radiates to carotids
- syncope
- angina
- dyspnea
Five causes of aortic stenosis + which is most common?
1: bicuspid aortic valve if pt is >40 yoa
- senile calcification
- chronic rheumatic heart disease
- tertiary syphillis
- unicuspid valve (rare)
What do ventricular septal defect, mitral regurgitation, and tricuspid regurgitation all have in common?
- All are holosystolic murmurs
- Differentiate based on location and clinical presentation
Mitral valve murmurs are best heard in what position?
left lateral decubitis
Mitral regurgitation:
where does it radiate
How is it effected by the hand grip maneuver? squatting?
- radiates to axilla
- worsened by hand grip and squatting
Most common cause of mitral regurgitation?
Rheumatic heart disease
Describe MVP murmur and one way to tell it apart from aortic stenosis?
- mid systolic click –> crescendo murmur
- murmur gets earlier with valsalva technique
- murmur improved with squatting (like HCOM)
Two causes of tricuspid regurgitation?
How can you tell it apart from VSD?
-RHD, endocarditis
VSD presents in an infant; tricuspid regurg common in adult IV drug users secondary to endocarditis
Valve most often effected by rheumatic fever?
mitral valve
