1. Intro and Laterality Flashcards
What is variation?
Abnormal in structure but not due to disease or trauma
Anatomical variation is a term used to describe any variant of the normal, expected anatomical presentation (Georgiev 2017).
Which paper looked at variations in surface anatomy?
Mirjalilli et al 2012
E.g. coeliac trunk at T12
What is the link between infants with minor and major abnormalities? Which paper looked at this?
Infants with >/3 minor abnormalities have 20% chance of major abnormalities
Sanudo et al 2003
What is situs solitus?
Normal position of thoracic and abdominal organs
What is situs inversus?
Major visceral organs are reversed from their normal positions
What is situs ambiguous?
Asymmetry of unpaired organs (heart, liver) - reversed association along L/R axis
Which tends to cause more symptoms - SI or SA?
SA (SI usually works, SA has more functional problems)
What is isomerism?
Asymmetry of paired organs
What is step 1 of L/R axis formation?
Break the global embryological symmetry and create centre of information (things usually pushed to left by cilia)
What is step 2 of L/R axis formation?
L/R information is propagated and spread to the lateral plate mesoderm
Asymmetric expression of genes in the left lateral plate mesoderm - depends on intact midline
What is step 3 of L/R axis formation?
Recognition by primordia and asymmetric morphogenesis
Unpaired organs - displace from midline or unilateral regression of a bilateral pair
Paired organs - direct translation of L/R signal
What paper highlighted the importance of scanning in SI patients?
Blegen 1949
45% error in diagnosis of SI patients
What did Fulcher and Turner (2002) investigate?
Patient with SI and lymphoma - mistakenly thought large node to right of aorta was IVC
IVC was actually on the left
What did Fang et al (2009) investigate?
Pacemaker insertion in patient with detrocardia and SIT
Apex on right of body
Challenging to place atrial and ventricular leads
