Difference between Veins and Arteries

In structure, veins and arteries are similar, having similar layer composition, but in function, they play different roles; there is a Difference between Veins and Arteries.

Veins

What are Veins

Veins are blood vessels that return deoxygenated blood from your organs and tissues back to your heart. The contracting skeletal muscles compress the Veins; as a result, directing the blood towards the heart. The walls of the Vein are thinner than Arteries, where arteries deliver oxygenated blood from your heart to the rest of your body.

Structure of a vein

Veins is similar to that of arteries, consisting of three layers:

Tunica Adventitia

This is the strong outer covering of arteries and veins, which consists of connective tissue, collagen, and elastic fiber.  Veins also contain valves that prevent the backflow of blood and aid venous return.

Vein types

Deep veins

These are located within muscle tissues.

Superficial Veins

These are closer to the skin surface.

Pulmonary Veins

 These veins are responsible for transport blood filled with oxygen by the lungs to the heart.

Major Veins

• Superior Vena cava
• Great Saphenous vein
• Femoral vein
• Basilic Vein
• Cephalic vein
• Axillary Vein
• Subclavian Vein

Arteries

Arteries are blood vessels responsible for carrying oxygen-rich blood away from the heart to the body via capillaries. Each artery walls are thicker because blood within the arteries is under high pressure; these muscular tubes are lined by smooth tissue and have three-layer-the Intima, which is the inner layer lined by a smooth tissue called the endothelium.

Function of arteries

The primary function of the Arteries is to carry oxygen-rich blood away from the heart. Pulmonary arteries are responsible for transporting blood with low oxygen content from the heart’s right ventricle to the lungs. In comparison, Systemic arteries are responsible for transporting oxygenated blood from the heart’s left ventricle to the body tissue.

Types of Arteries

• Elastic arteries: Aorta and Pulmonary
• Muscular arteries: Brachial Arteries and Radial artery
• Arterioles  

 Largest  Artery: Aorta

• The movement towards the heart
• The function involves the collection of blood from body organ
• Possess relatively less elastic/muscular tissue.
• Thin, collapsible outer layer.
• Veins have a larger lumen
• The blood flow speed is low (slow)
• Dark red 
• Blood pressure less “0” mm/Hg.
• Transport blood under lower pressure
• Contains blood after death
• Valves are present
• Amount of blood 64 percent at a given time
• Lymphatic capillary are present in the vein wall
• Tunicaexterna is more developed and very strong
• Transport deoxygenated blood
• Located near the body surface
• pH is comparatively lower

• The movement of the oxygenated blood away from the heart.
• The function is to supply blood to the body organs.
• Arteries possess relatively more elastic/muscular tissue.
• It has a thick muscular, noncollapsible outer layer
• It has a smaller lumen
• The blood flow speed is fast.
• Pink in color
• The pressure of blood 120/80 mm/Hg
• Transport blood under high pressure 
• Arteries become empty after death.
• Valves are absent in arteries(except,semi-lunar valves)
• The amount of blood is 15 percent at any given time
• Lymphatic capillary are absent in artery wall
• Tunicaexterna is less developed and not very strong
• Transport oxygenated blood
• Located deep to the body surface
• Blood pH is 7.40