CVS: concept & process of septation

Question 1

What does right atrium develop from ?

Answer 1

most of the primitive atrium and sinus venosus

Question 2

Right atrium receives venous drainage (deoxygenated blood) from where ?

Answer 2

the body via venae cavae

Question 3

left atrium develops from what ?

Answer 3

a small portion of the primitive atrium

Question 4

left atrium absorbs ..1…. and receives ..2… from the lungs

Answer 4

1. proximal parts of pulmonary veins
2. oxygenated blood

Question 5

slide 7-8

Question 6

Septation occurs between what weeks ?

Answer 6

4 and 7

Question 7

Changes in heart before and after septation

Answer 7

before = single-channel peristaltic pump
after = dual-channel, synchronously contracting device with one-way valves

Question 8

Septation of heart involves what ?

Answer 8

• interatrial septum formation
• interventricular septum formation
• septation of ventricular outflow tract into pulmonary trunk & aorta by aorticopulmonary septum (spiral)

Question 9

2 basic processes that play key roles in generating septa ?

Answer 9

1. Differential growth and remodelling are mainly responsible for generating the muscular
   ventricular and atrial septa (these do not completely separate the heart chambers)
2. Cushion tissue derived from the endocardium (mesoderm) and neural crest cells (ectoderm)

Question 10

formation of atrioventricular canal

Question 11

formation of interatrial septum

Question 12

repositioning of the sinus venosus and the venous inflow into the right atrium…

Question 13

slide 17-18 ‘septation of the ventricles’

Question 14

formation of the aorticopulmonary septum …

Question 15

foetal circulation ..