Cardiovascular Accidents

Myocardial Infarction

A great amount of people everyday suffer from cardiovascular accidents such as infarction of the heart. These accidents affect the vascular system as well as the heart itself and represent the most common cause of death around the world.

King Saud University
Source: http://faculty.ksu.edu.sa/73698/Pictures%20Library/Forms/AllItems.apx

Micro Circulation

Source: http://microcirculation.blogspot.com/2008/07/understanding-myocardial-infarction.html

Deposits of fat and cholesterol can take place within vessels causing narrowing of the arteries. such deposit is related to a high-fat diet. in addition, blood clots are likely to form at the site of fatty deposits leading to blockage of an artery, thus impairing blood circulation within such area.

Infarction

The heart muscle receives blood from the coronary vessels that surround the cardiac muscle. If one of the arteries that form part of the coronary circulation becomes partially clogged, the area of the heart normally supplied by this artery would be deprived from nutrients and oxygen. As a result, this area will stop contracting and eventually die. The cardiac cycle will get disturbed, anticipating the beginning of an infarction.

Four major factors that can lead to the development of an infarction include: high-fat diet, stress, lack of exercise and smoking. individuals experiencing the beginning phase of an infarction, usually complain from severe chest pain that spreads to the left arm, shoulder and epigastric region, sweating, nausea, vomiting, fatigue and intense discomfort.

What are the main causes of an infarction? How can we avoid it?

Reference:

Lebdeh, D., Dakroub, R., Seif, N., & Jarjour, Z. (2000). Life and Earth Sciences. Sin-El-Fil, Lebanon: Lebanese Educational Publishing Company.

Blood Vessels

Blood should be distributed through the body in a way that satisfies the needs of all body organs and tissues for provision of oxygen and nutrients. As a result, once the blood gets oxygenated in the pulmonary system, it enters the heart to be pumped into a network of blood vessels with different characteristics.

An artery directly supplies an organ and then divides into smaller arteries called Arterioles. These arterioles divide in turn into smaller and thinner vessels called Capillaries, which supply with blood and nutrients to cells and participate in blood exchange at the level of the organs. Capillaries the join together to give rise to big vessels called Venules. The Venules join to form veins, which direct blood in a backward fashion, from the tissues and organs back to the heart.

Source: Medical Management of vascular conditions

http://nyp.org/health/cardiac-manage.html

Dynamics of Circulation

Circulation refers to the continuous flow of liquids that make up the body system. Blood circulates in a closed system. The human body accounts of two types of circulatory systems. The Pulmonary Circulation, which is responsible of oxygenating blood and getting rid of the carbon dioxide. In this circulatory network, blood flows from the pulmonary artery into the lungs then back through the pulmonary veins into the heart. The Systemic Circulation supplies every organ with nutrients and oxygen and carries away waste products. This circulatory system consists of the aorta and the two venae cavae. Together the Pulmonary and Systemic circulation constitute the human body blood circuit.

Source: Patterns in Assistive Technology Training and Services
http://webschoolsolutions.com/patts/systems/heart.htm

Arteries of the systemic circulation contain blood rich in which component?

Reference

Lebdeh, D., Dakroub, R., Seif, N., & Jarjour, Z. (2000). Life and Earth Sciences. Sin-El-Fil, Lebanon: Lebanese Educational Publishing Company.

Cardiac Activity

The heart is a muscle that contracts regularly at around 70 beats per minute. Heart contractions allow blood pumping to all body organs and tissues. Contractions of the atriums and ventricles occur simultaneously. During each heart beat, the right ventricle sends blood through the pulmonary artery into the pulmonary system. Once in the pulmonary system, blood gets oxygenated and its send back through the pulmonary veins into the left atrium, which ultimately carries blood to the left ventricle to be pumped through the aorta thus distributing it to the rest of the body.

Source: (Blood pressure monitoring)

http://kushtripathi.wordpress.com/2009/12/01/blood-pressure-monitor/

What's the difference between the systolic and diastolic phase of the cardiac cycle?

Reference:
Lebdeh, D., Dakroub, R., Seif, N., & Jarjour, Z. (2000). Life and Earth Sciences. Sin-El-Fil, Lebanon: Lebanese Educational Publishing Company.

The Heart

The heart is an organ made up of a hollow muscle called the myocardium. The main function of the heart is to pump blood through a system of blood vessels to all body organs and tissues. The heart of an adult weight approximately 300 grams. The right and left heart do not communicate, blood circulates inside structures that prevent back flow due to presence of one way valves.

What structure of the heart permits this function? How is the cardiac activity manifested?

Source: Geriatrics: Aging changes in Cardiovascular System (Heart and Blood Vessels): http://latitudes.sulekha.com/blog/post/2008/10/geriatrics-aging-changes-in-cardiovascular-system.htm

Welcome!!

Welcome to the Cardiac System Blog. This blog is offered to Grade 9 students. We will use it to share information and post announcements.