Science & Technology in Action

6th Edition

Closing The Wound


Jnr Science Cert
Modern medicine relies heavily on the use of medical devices. This lesson describes how an innovative bioabsorbable wound closure device is used in medical procedures such as an angioplasty. The cardiovascular system and some of its medical problems are described.
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Lesson excerpt

Modern medicine relies heavily on the use of medical devices. Amedical device is anything that is used for medical purposes – diagnosis, treatment or surgery. This includes x-ray machines, artificial limbs and thermometers. Many are used in combination to carry out medical procedures. For example, carrying out a procedure such as an angioplasty could use catheters, stents and wound closure devices. In this lesson we look at how a newbioabsorbable wound closure device produced by Cordis is used in carrying out medical procedures. To set the background, we describe the cardiovascular system and some of its medical problems.

Overview of Human Circulatory System
Large animals such as humans need a circulatory system in order to transport oxygen and other nutrients around the body. The human system circulates blood and is a closed system. It is described as a double circulatory system. A closed systemmeans that the blood is contained in a network of blood vessels. Blood is made up of red blood cells, white blood cells, platelets and plasma. It is a double circulatory system because there are two separate systems at work – the systemic circulatory system and the pulmonary circulatory system. Thesystemic circulatory system transports blood from the heart, around the body and back to the heart. The pulmonary circulatory system transports blood from the heart to the lungs and back again.

The heart is at the centre of the circulatory system and acts as a pump which sends blood to all parts of the body including the lungs. Arteries and the smaller arterioles transport oxygenated blood around the body from the heart. Tiny capillaries allow the oxygen and nutrients to diffuse into the cells where they are needed. Veins and the smaller venules take deoxygenated blood back to the heart.

What Can Go Wrong?
For this system to be effective, it needs to be working well. Various activities in a person's lifestyle, such as smoking, poor diet and lack of exercise can lead to fatty deposits such as cholesterol building up on the walls of the arteries. When cholesterol builds up on the artery walls, the arteries harden and become narrower, making it more difficult for blood to flow through them. This narrowing is known as stenosis. The disease causing this isatherosclerosis and can lead to heart attacks and death.

True or False?

  1. The narrowing of an artery is called angioplasty. false
  2. Blood travels from the lungs to all parts of the body. false
  3. Polyglycolic acid (PGA) breaks down to form carbon dioxide and water. true
  4. The ExoSealTM plug breaks down in the human body in 6-10 hours. false
  5. Medical devices need extensive testing before they can be used. true
  6. Veins carry oxygenated blood to all parts of the body. false
  7. Polyesters are condensation polymers. true
  8. Arteries can be unblocked using manual compression. false
  9. Stents are commonly used as wound closing devices. false
  10. The human circulatory system is a closed system. true