2/21 Flashcards
Primitive pulmonary vein
smooth part of left atrium
Left horn of sinus venosus
coronary sinus
Right horn of sinus venosus
smooth part of right atrium
What is the first functional organ in vertebrate embryos?
-what week does it start functioning?
- heart
- week 4
When does cardiac looping happen?
-what can go wrong here?
- week 4
- Kartagener syndrome & dextrocardia
What fuses to make the membranous IV septum
- muscular interventricular septum
- aorticopulmonary septum
- little by the endocardial cushions
Where is a VSD most commonly seen?
-membranous IV septum
What are all the heart valves derived from?
-endocardial cushions
4 places that fetal erythropoiesis happens.
- Yolk sac (3–8 weeks)
- Liver (6 weeks–birth)
- Spleen (10–28 weeks)
- Bone marrow (18 weeks to adult)
*Young Liver Synthesizes Blood.
ductus venosus
-what does this bypass?
-Bypasses hepatic circulation. Blood shunted to IVC instead.
What is the formane ovale called after it closes?
-fossa ovalis
Where was most of the PGE1 & PGE2 coming from that kept the ductus artiosus open?
-placenta
# of umbilical arts? # of umbilical veins?
- 2 umb. arts
- 1 umb vein.
Umbilical vein
Ligamentum teres hepatis
-Contained in falciform ligament.
UmbiLical arteries
MediaL umbilical ligaments
Ductus arteriosus
Ligamentum arteriosum
Ductus venosus
Ligamentum venosum
AllaNtois
Urachus-mediaN umbilical ligament
- The urachus is the part of the allantoic duct between the bladder and the umbilicus.
- Urachal cyst or sinus is a remnant.
Notochord
Nucleus pulposus of intervertebral disc
which coronary art supplies the SA & AV nodes?
RCA
Right/Left dominant heart depends on whether or not its the RCA or LCX gives off which art?
Posterior descending art.
-85% of time its RCA = right dominant.
LAD occlusion: which leads STEMI?
V1-V3
Ficke principle
CO = rate of O2 use/(arterial O2 - venous O2)
Extracellular sodium conc.
-relationship to inotropy of heart?
- Na/Ca exchanger. Pumps Ca out in exchange for bringing a Na into cell down its conc. gradient.
- The less extracellular sodium = less this pump works b/c of the dec. Na gradient = more Ca stays in the cell = more contractility of cardiac myocyte.
- pretty much same thing as digitalis/digoxin except thats inc. the intracellular Na to dec. the conc. gradient to slow down the Na/Ca pump to inc. intracellular Ca.
- blocks the Na/K ATPase
Effect of acidosis on heart inotropy?
-acidosis decreases heart contractility.
Afterload equation:
Wall tension =
wall tension = (pressure * radius)/(2*wall thickness)
Ejection fraction
- in systolic failure
- in diastolic failure
- systolic failure = dec.
- diastolic failure = same
Spherocytosis
-does it inc. or dec. viscosity of blood?
-inc.
Whats the period of highest O2 consumption by the heart?
-isovolumentric contraction of left ventricle.
a wave
-positive wave
atrial contraction
c wave
-positive wave
beninning of RV contraction
-blood rushes against the close tricuspid valve, which pushes in a little and causes inc. pressure in LA.
x descent
- negative wave
- atrial relaxation. last half of RV contraction.
- downward displacement of closed tricuspid valve during RV contraction. Blood rushes past it and little vacuum forms and pulls the tricuspid down a little.
- this is absent in tricuspid regurg.
which wave is absent in tricuspid regurg?
x descent