Understanding the Circulatory System: Arteries, Veins, and Blood Flow

Systemic: Series of Arteries and Veins

A systemic circulation consists of a series of arteries that deliver oxygenated blood to capillary beds within body tissues, and a set of veins that return deoxygenated blood back to the heart.

Coronary: Supplying the Heart

The coronary circulation is similar to the systemic circulation, but its arteries, capillary beds, and veins supply and drain only the heart.

Pulmonary: Blood Flow to the Lungs

The pulmonary circulation features a set of arteries that deliver deoxygenated blood to the capillary beds of the lungs, and a set of veins that return oxygenated blood to the heart.

Blood Flow into the Heart

Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium.

Differences Between Arteries and Veins

Arteries and veins experience differences in the pressure of blood flow, which is reflected in the structure of the vessels. Veins have thinner walls and less tunica media compared to arteries.

Pulse Palpation: Feeling the Arterial Pulsations

Pulse palpation is the process of using the fingertips to feel pulse points, such as the radial, ulnar, brachial, carotid, temporal, femoral, popliteal, posterior tibial, and dorsalis arteries.

The Dangers of Improper Tourniquet Use

Improper use of a tourniquet can worsen bleeding by blocking venous blood flow while arterial blood continues to pass by. Releasing the tourniquet too soon can cause severe bleeding to resume and damage compressed blood vessels.

Screening for Carotid Artery Disease

If an abnormal sound, called a bruit, is heard over an artery, it may indicate turbulent blood flow and potential carotid artery disease. Listening for a bruit in the neck is a simple, safe, and inexpensive way to screen for carotid artery stenosis, although it may not detect all blockages.