CVS Flashcards
What is the major component in diffusion resistance?
Path length
What 3 things affect rate of diffusion?
Area available
Concentration gradient
Diffusion resistance
What is meant by capillary density?
Capillaries per unit volume.
Tissues which are more metabolically active will have a greater capillary density.
Should be noted not all capillaries are always perfused
How is perfusion rate described?
Rate of blood flow through a tissue
What is a pericyte and what is its role on a continuous capillary?
Contractile cell wrapped around endothelium which allows endothelium to differentiate and perform angiogeneis
What is a pinocytic vesicle?
Invagination of plasma membrane which has formed a vesicle containing extracellular contents in a fluid filled vacuole.
What is the haemodynamic effects associated with atrial septal defects?
Increased pulmonary blood flow
RV volume overload
Could result in pulmonary hypertension (rare)
Eventual right heart failure
What is the haemodynamic effects associated with ventricular septal defect?
Left to right shunt
LV volume overload
Pulmonary venous congestion
Eventual pulmonary hypertension
What genetic condition is associated with atrio-ventricular defect?
Down syndrome
What problems are associated with tetrology of fallout?
Overriding aorta
Right ventricle hypertrophy
VSD
Pulmonary stenosis
Describe the pathophysiology of tricuspid atresia
No RV inlet (tricuspid valve)
Right to left shunt of entire venous return (very bad)
Blood can get to lungs via PDA or VSD.
have to surgically recreate a PDA if not one available (cannot survive without)
Explain hypo plastic left heart
Left ventricle severely underdeveloped
Ascending aorta very small
Right ventricle supports systemic circulation, utilising right to left shunt
Explain transposition of great arteries
Aorta and pulmonary artery attached to wrong sides. Aorta to right and pulm to left. Must have bidirectional shunting for survival
Describe pulmonary atresia
No blood flow from right ventricle to lungs
Must have PDA to allow blood flow to lungs (from aorta)
Right to left atrial shunt of entire venous return
If left untreated, what kind of septal defect can lead to inoperable pulmonary hypertension?
VSD
what kind of septal defect usually presents in infancy with left heart failure?
VSD
unless very small
When and how would a ASD present?
Mostly asymptomatic until adulthood when presenting as late onset arrhythmia and right heart failure
When would tetralogy of fallout present?
Normally in infancy with cyanosis
Can be later on into adulthood if mild
What is eisenmengers syndrome?
In a left to right shunt defect, sometimes pulmonary resistance can increase so much that pressure becomes higher on the right side of the heart. This can make the shunt go right to left and cause cyanosis.
