AEMCA Practice Exam

What is the first structure that blood passes through when it enters the kidneys from the aorta?

1. Renal vein

2. Renal artery

3. Afferent arteriole

4. Glomerulus

The correct answer is: Renal artery

The first structure that blood encounters when it enters the kidneys from the aorta is the renal artery. The renal artery branches off from the abdominal aorta and carries oxygenated blood directly to the kidneys. Once the blood enters through the renal artery, it eventually travels through smaller branches and arterioles, leading to the afferent arteriole, which then directs the blood into the glomeruli for filtration. Understanding the sequence reinforces the pathway of blood through the renal system. The renal vein operates in the opposite direction, carrying deoxygenated blood away from the kidneys back towards the heart. The afferent arteriole serves as a subsequent structure in the blood flow after the renal artery has fulfilled its role of supplying blood to the kidneys. Meanwhile, the glomerulus is a network of capillaries where filtration occurs, but it is not the initial entry point for blood from the aorta.