The Systemic Circuitby Linda Langevoort

Anatomy & Physiology Class / South University Online

(Buzzle.com, 2011)

Introduction

• The Systemic Circuit, which lies in the Cardiovascular System,functions to transport blood to and from the rest of the body.(Martini, Nath, Bartholomew, 2012, pg. 670)

• The circuit begins and ends at the heart. (Martini, Nath, Bartholomew, 2012, pg. 670)

• Blood travels in a sequence and has to make a complete cyclethroughout the body and then it can return to the heart.(Martini, Nath, Bartholomew, 2012, pg. 670)

• I will discuss this circuit and the arteries and veins supporting it.

• I will show areas of the body that this system supplies.

Blood Distribution

• The Systemic Circuit contains 84% of the blood volume in the body. (Martini, Nath, Bartholomew, 2012, pg.737)

•

(Martini, Nath, Bartholomew, 2012, pg.717)

The Systemic Circuit is comprised of the vessels between the aortic valve and the entrance to the right atrium.

In this photo: Blood flowing along the systemic circuit picks up oxygen and deoxygenated blood. This accounts for the change of color in this diagram from red to blue.

(Marieb, Mitchell, 2009, pg. 447)

Blood Flow

Systemic circulation carries oxygenated blood from the left ventricle through the arteries, to the capillaries. (Darling)

From there it carries it to the lower tissues of the body, providing oxygen and nutrients. (Darling)

The tissue capillaries return the deoxygenated blood by way of veins to the right atrium of the heart. (Darling)

(Darling)

Route of Blood Flow

Arteries carry blood away from the heart . (Martini, Nath, Bartholomew, 2012, pg. 738)

Veins carry blood towards the heart. (Martini, Nath, Bartholomew, 2012, pg. 738)

(Martini, Nath, Bartholomew, 2012, pg. 737)

Diagram:The red areas [bottom half of the photo] are showing the flow of blood to the lower limbs, tissues and organs.

The blue areas (bottom half of the photo] are showing the veins returning the blood to the heart.

The Circuit

Systemic Main Arteries

• From the Aorta (3 portions):

1. Ascending Aorta

2. Aortic Arch

3. Descending Aorta

• From the Descending Aorta (2 portions)

1. Thoracic aorta

2. Abdominal Aorta

(Martini, Nath, Bartholomew, 2012, pg. 739)

[Darling]

The Ascending Aorta begins at the aortic valve of the left ventricle. Connecting to the ascending Aorta, the Aortic Arch curves and meets up with the Descending Aorta. (Martini, Nath, Bartholomew, 2012, pg. 740)

Arteries (Aorta)

(Educational Communications Board, 2011)

Arteries (Descending Aorta)

The Descending Aorta continues into the Thoracic Aorta and the Abdominal Aorta.

The Abdominal aorta delivers all the blood to the abdominopelvic organs and structures.

(Martini, Nath, Bartholomew, 2012, pp. 740-741)

Systemic Main Veins

• From the Superior Vena Cava

1. Inferior Vena Cava

2. Right Atrium

Once the arterial blood delivers oxygen to the tissues and picks up carbon dioxide, it then can return the blood to the heart through its system of veins.

(Martini, Nath, Bartholomew, 2012, pg. 749)

[Darling]

Veins and Blood Return

The veins of the lower limbs and organs flow towards the Hepatic Portal Vein. Then the blood flows to the Inferior Vena Cava and Superior Vena Cava entering into the Right Ventricle. The Right Ventricle returns the oxygenated blood to the lungs and Right Atrium to begin the cycle again.

(Hussainz, 2012)

(Martini, Nath, Bartholomew, 2012, pp. 749-753)

Pump that Blood

• Blood pressure keeps the blood flowing from the areas of higher pressure to the areas of lower pressure.

• Higher arterial pressures overcome peripheral resistance and keep the blood flow regular through the peripheral tissues.

• Valves and muscle compressions and the respiratory pump help to move the blood back toward the heart.

(Martini, Nath, Bartholomew, 2012, pg. 760)

(Sinatra, MD, 2008)

The End