Blood flow through the heart

Blood moves into and out of the heart in a well-coordinated and precisely timed rhythm.

Aorta

Superior vena cava

Pulmonary artery

Pulmonary veins

Right atrium

Right ventricle

Inferior vena cava

Pulmonary artery

Left atrium

Left ventricle

Septum

Descending aorta

Deoxygenated blood Lungs

Oxygenated blood

Pulmonary artery

Left atrium

Left ventricle

Septum

Descending aorta

^eft atrium

Deoxygenated blood Lungs

Oxygenated blood

^eft atrium

Pulmonary veins

Aorta

Right ventricle

Left ventricle

Head and arms t

Systemic circulation

Right ventricle

Left ventricle

Pulmonary veins

Aorta

Head and arms t

Systemic circulation

Liver

Stomach and intestines

Kidneys, reproductive organs, lower limbs

Branches of the aorta

Fig 5.9 Blood flow through the heart

For descriptive purposes the blood flow can be divided into three stages:

Stage 1

Deoxygenated blood from the body enters the superior and inferior vena cava and flows into the right atrium. When the right atrium is full, it empties through the tricuspid valve into the right ventricle

Stage 2

When the right ventricle is full, it contracts and pushes blood through the pulmonary valve into the pulmonary artery. The pulmonary artery divides into the right and left branch and takes blood to both lungs where the blood becomes oxygenated. The four pulmonary veins leave the lungs carrying oxygen-rich blood back to the left atrium

Stage 3

This process takes place at the same time as the process described in stage 1. Oxygen-rich blood leaves the left atrium and passes through the left ventricle via the bicuspid or mitral valve. When the left ventricle is full it contracts, forcing blood through the aortic valve into the aorta and to all parts of the body (except the lungs). The walls of the left ventricle are thicker in order to provide the extra strength to push blood out of the heart and around the body

Student activity

Now complete Activity 5.1 in the resources for this book on Dynamic Learning Online.

From Pain To Freedom

From Pain To Freedom

From Pain To Freedom is the Latest Scientific and Natural Medicine Breakthroughs to Understand and Relieve the Symptoms of Fibromyalgia!

Get My Free Ebook


Post a comment