San Bernardino County Sheriff's Department Infographic Thursday, November 16, 2017 The San Bernardino County Sheriffâs Department is the law enforcement agency for the largest geographical county in the nation. The department serves over 2.1 million residents with 15 patrol stations and 3800 employees to ensure the quality and safety of those we serve...
Veins branch at their beginnings into tiny venules which join capillaries.  Veins have valves which stop the blood from flowing backward. Compared to the arteries, pressure in the veins is very low. The blood is being pushed through the arteries as the heart squeezes the blood out. This is not true for the veins. Blood is pushed through the veins when body muscles contract and squeeze the veins.
The walls of veins have the same three layers as the arteries. Although all the layers are present, there is less smooth muscle and connective tissue. This makes the walls of veins thinner than those of arteries, which is related to the fact that blood in the veins has less pressure than in the arteries.Because the walls of the veins are thinner and less rigid than arteries, veins can hold more blood.apillaries. Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins).