Circulus Arteriosus

Question 1

Circulus arteriosus

Answer 1

Circle of Willis

Question 2

Site

Answer 2

1. Lies in Interpeduncular cistern at brain base in Interpeduncular fossa neighborhood
2. Around hypothalamus region

Question 3

Formation

Answer 3

1. 6 large arteries
2. 3 communicating arteries

Question 4

6 large arteries

Answer 4

1. Right and left cerebral arteries
2. Right and left internal carotid arteries
3. Right and left posterior cerebral arteries

Question 5

Size of arteries

Answer 5

It is common for them to be very small or even completely absent without any clinical disturbances under normal conditions

Question 6

Anastomoses

Answer 6

Cortical branches anastomose with one another before entering brain while central branches are end arteries

Question 7

Clinical importance

Answer 7

Under normal conditions, little mingling of blood of both sides occurs but if one big artery becomes closed before it enters in circle formation, the connections may open up