do veins have valves?

-Yes, some veins have one-way valves to help keep blood flowing in the right direction.

what are the 2 types of veins?

-Pulmonary veins. The pulmonary circuit carries deoxygenated blood from your heart to your lungs. Once your lungs oxygenate the blood, the pulmonary circuit brings it back to your heart. There are four pulmonary veins. They’re unique because they carry oxygenated blood. All other veins carry only deoxygenated b…[Read more]

Veins and venules have much thinner, less muscular walls than arteries and arterioles, largely because the pressure in veins and venules is much lower. Veins may dilate to accommodate increased blood volume. If a blood vessel breaks, tears, or is cut, blood leaks out, causing bleeding.

The nervous system is the major controlling, regulatory, and communicating system in the body. It is the center of all mental activity including thought, learning, and memory. Together with the endocrine system, the nervous system is responsible for regulating and maintaining homeostasis. Through its receptors, the nervous system keeps us in touch…[Read more]

Accuracy measures how close results are to the true or known value. Precision, on the other hand, measures how close results are to one another.