Question

In which of the following ways do the veins differ from the arteries in mammals?
A. Thicker walls
B. Deeply present
C. Carry blood away from the heart
D. Internal valves

Answer 1

Hint: They are a one-way valve that allows the blood to flow only in one direction throughout the heart and prevent the backflow of blood.

Complete answer:
Arteries and veins are the blood vessels that carry blood in the heart. Veins carry deoxygenated blood towards the heart and have thin walls as compared to arteries. They carry blood in unidirectional flow and prevent them from going backward.

Additional information
- Arteries carry oxygenated blood away from the heart while veins carry deoxygenated blood towards the heart.
- Arteries have thicker walls than veins because they must be able to withstand the large pressure from a beating heart.
- Veins have thinner walls as it requires a large space to hold blood.
- Veins have less smooth muscles than arteries as arteries accumulate the pulses of blood generated by each contraction of the heart.
- The arteries consist of three layers: tunica intima, tunica media, and tunica adventitia.
- The veins also consist of three which stores extra blood from the heart.
- Arteries are elastic and thick because their blood is transported in a high pressure while in veins it flows in low pressure.

So, the correct answer is Internal valves.

Note: Heart valves are flap-like structures that allow blood to flow in one direction and prevents the backflow of blood. There are four valves of the heart: Aortic valve (pumps blood from the left ventricle to aorta), Mitral valve (pumps blood from left atrium to the left ventricle), Pulmonary valve (pumps blood from right ventricle to pulmonary artery), and Tricuspid valve (pumps blood from atrium to the right ventricle).