Difference between Veins and Arteries

 

Key Difference: Veins are blood vessels that are responsible for carrying deoxygenated blood from various parts of the body to the heart. Arteries are blood vessels that are responsible for carry fresh oxygenated blood from the heart to the rest of the body.

 

Veins and arteries are two major parts of the human anatomy and they play a very important part in how blood flows throughout the body. These are both a part of the pulmonary and systemic circulation, which is important for surviving as they provided the needed nutrients and blood required by the body. Though they are similar in texture and definition, they differ in structure and function. Due to the slight differences, the terms can be confusing.

 

 Veins, part of the circulatory system, are blood vessels that are responsible for carrying deoxygenated blood to the heart. The purpose of most veins is to take deoxygenated blood from tissues in various parts of the body and bring it back to the heart. Exceptions to this are pulmonary veins and the umbilical veins. The pulmonary veins carry the oxygenated blood from the lungs to the heart.

 

The veins are composed of three layers; the outer layer, tunica adventitia or tunica externa, is made up of connective tissue, thin muscle layer in the middle, called tunica media and an inner layer of epithelial cells known as tunica intima. The layers are thin and weak and collapsible, if no blood passes through them. The placement of the veins in a body varies depending on the person and is generally closer to the skin, which is why they can be sometimes seen on the hands and wrists. They are actually deep red in color, but due to the light reflection on the skin, they look blue. They veins are generally weaker compared to arteries because they carry blood at a lower pressure.

 

Veins receive blood from the capillaries after they have exchanged the deoxygenated blood with oxygenated blood. The veins then carry the waste-rich blood back to the heart, which goes through the process of being oxygenated again for transfer. The veins also have valves inside the last layer that keeps the blood flowing in one direction and eliminates backward flow. Veins play an important part in the body as it also has to work against the flow of gravity. The body that is below the heart requires an extra foothold in order for the blood to flow back upwards, against the gravitational force.

 

Arteries are similar to veins but they perform the opposite of veins, which is to take oxygenated  blood from the heart to the body, with the exceptions being pulmonary and umbilical arteries. The arteries are responsible for carrying oxygen-rich blood from the heart to the various different parts of the bodies, where it then replaces deoxygenated blood with fresh oxygen-rich blood. However, the pulmonary artery takes deoxygenated blood from the heart to the lungs, where oxygen is added to the blood to make it into oxygenated blood. Arteries also aid the heart in pumping blood.

 

The arterial system is a high-pressure system, whose pressure varies between the peak pressure during heart contraction and the minimum pressure between contractions. This pressure is identifiable in any artery, which produces a pulse when it contracts and expands. This pressure variation is used by doctors and medical professionals in order to determine your heartbeat. Arteries are also composed of three layers similar to those of veins: the tunica externa, the tunica media and the tunica intima. The tunica externa is made up of connective tissue, the tunica media is made up of thick, smooth muscle cells and elastic tissue, while the tunica intima is made up endothelial cells. Arteries are thicker compared to veins as they have to also sustain the pressure with which the heart pumps the blood.

 

The main process is something like this; the heart pumps the blood through the dorsal aorta, a main artery, which is then divided into smaller arteries that runs all around the body in order to deliver blood and nutrients to the body. The blood is then passed on from the dorsal aorta to the other smaller arteries. Arteries are tough on the outside and smooth on the inside in order to keep a continuous blood flow to all the parts of the body. When the heart pumps blood into the artery, it expands and when the heart relaxes, the artery contracts helping push the blood to the other arteries. Another purpose of this is to send blood flowing against the gravitational pull. This is mostly required in order to send blood to the parts above the heart, such as the brain. If the brain does not receive blood, it results in a person fainting, in order to bring the brain down to the same level as the heart, making it easier for the brain to receive blood.

 

Both the arteries and veins work together in order to create the pulmonary and systemic circulation which is crucial for survival and for the body staying fit and healthy.

 

 

Veins

Arteries

Definition

Veins are blood vessels that are responsible for carrying deoxygenated blood from various parts of the body to the heart, except the pulmonary and umbilical veins.

Arteries are blood vessels that are responsible for carry fresh oxygenated blood from the heart to the rest of the body, except for the pulmonary and umbilical arteries.

Purpose

Veins carry deoxygenated blood to the heart (with the exception of pulmonary veins and umbilical vein).

Arteries carry oxygenated blood from the heart to the body (with the exception of pulmonary arteries and umbilical arteries).

Types

Superficial veins, deep veins, pulmonary veins and systemic veins.

Pulmonary, systemic arteries, Aorta and arterioles.

Direction of Blood Flow

From the different parts of the body to the heart.

From the heart to the rest of the body.

Anatomy

Veins have three layers:

Outer layer of tissue, thin muscle layer in the middle and an inner layer of epithelial cells. The layers are thin and weak and collapsible, if no blood passes through them.

Arteries have three layers: Outer layer of tissue, muscular middle later and an inner layer of epithelial cells. The middle muscle layer is thick and strong in order to sustain the pressure of the blood flow. The arteries are smooth on the inside.

Walls

Collapsible

Rigid

Thickest Layer

Tunica Adventitia

Tunica Media

Color

Dark red, seems almost blue

Red

 

 

Image Courtesy: wikipedia.org
Image Courtesy: wikipedia.org

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Comments

would like to know why an artery in leg would burst and does it repair again .

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