CVS

Question 0

What is the major component in diffusion resistance?

Answer 0

Path length

Question 1

What 3 things affect rate of diffusion?

Answer 1

Area available
Concentration gradient
Diffusion resistance

Question 2

What is meant by capillary density?

Answer 2

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

Question 3

How is perfusion rate described?

Answer 3

Rate of blood flow through a tissue

Question 4

What is a pericyte and what is its role on a continuous capillary?

Answer 4

Contractile cell wrapped around endothelium which allows endothelium to differentiate and perform angiogeneis

Question 5

What is a pinocytic vesicle?

Answer 5

Invagination of plasma membrane which has formed a vesicle containing extracellular contents in a fluid filled vacuole.

Question 6

What is the haemodynamic effects associated with atrial septal defects?

Answer 6

Increased pulmonary blood flow
RV volume overload
Could result in pulmonary hypertension (rare)
Eventual right heart failure

Question 7

What is the haemodynamic effects associated with ventricular septal defect?

Answer 7

Left to right shunt
LV volume overload
Pulmonary venous congestion
Eventual pulmonary hypertension

Question 8

What genetic condition is associated with atrio-ventricular defect?

Answer 8

Down syndrome

Question 9

What problems are associated with tetrology of fallout?

Answer 9

Overriding aorta
Right ventricle hypertrophy
VSD
Pulmonary stenosis

Question 10

Describe the pathophysiology of tricuspid atresia

Answer 10

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)

Question 11

Explain hypo plastic left heart

Answer 11

Left ventricle severely underdeveloped
Ascending aorta very small
Right ventricle supports systemic circulation, utilising right to left shunt

Question 12

Explain transposition of great arteries

Answer 12

Aorta and pulmonary artery attached to wrong sides. Aorta to right and pulm to left. Must have bidirectional shunting for survival

Question 13

Describe pulmonary atresia

Answer 13

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

Question 14

If left untreated, what kind of septal defect can lead to inoperable pulmonary hypertension?

Answer 14

VSD

Question 15

what kind of septal defect usually presents in infancy with left heart failure?

Answer 15

VSD

unless very small

Question 16

When and how would a ASD present?

Answer 16

Mostly asymptomatic until adulthood when presenting as late onset arrhythmia and right heart failure

Question 17

When would tetralogy of fallout present?

Answer 17

Normally in infancy with cyanosis

Can be later on into adulthood if mild

Question 18

What is eisenmengers syndrome?

Answer 18

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.