[L3 Anatomy and Physiology] Section 1: The heart and circulatory system Flashcards
What is the myocardium?
The Cardiac muscle, which is the predominant tissue of the heart.
How does the heart prevent unwanted backflow of blood into the chambers of the heart?
Using a number of valves
The valves open and close in response to what?
Changes in pressure as the heart contracts and relaxes
What are the main valves of the heart?
Atrioventricular (AV) valves and the Semilunar (SL) valves
Where is the Atrioventricular (AV) valve located
The AV valves are located between the atria and the ventricles and prevent the back-flow of blood from the ventricles into the atria.
Where is the Semilunar (SL) valve located
The SL valves are located at the base of the arteries leaving the heart (aorta and pulmonary artery).
What is Coronary Circulation?
The circulation of blood to the heart
The heart, like any other tissue, requires a
constant supply of what?
Oygen and Nutrients
The right coronary artery supplies blood to which area of the heart?
Myocardium of the right ventricle
The left coronary artery supplies blood to which area of the heart?
Myocardium of the left ventricle and posterior of heart.
Blood supply to the tissues can be maintained despite vessels becoming damaged (due to heart desease), because of what?
Most regions of the heart are served by more than one branch of coronary arteries.
What is ischaemia?
Reduction in blood flow
What is Myocardial ischaemia and what can it cause?
Reduction in blood flow to the heart through coronary circulation and can result in a myocardial infarction (or a heart attack)
Most heart problems can be attributed to poor coronary circulation as a result of?
Blood clots, fatty plaques building up in the coronary arteries or spasms in the smooth muscle of their walls
Vascular disease is?
The narrowing of the blood vessels
Vascular disease is one of the main causes of death in the developed world and it is caused by?
Inflammation in blood vessels, accumulation of mineral, protein and fat deposits, which create a build-up of plaques on vessel walls.
What is atherosclerosis?
Hardening of the arteries
Describe what happends when an atery becomes inflamed or damaged.
Plaque forms on the artery walls (as the body attempts to repair the artery using cholesterol, protein and mineral deposits).
(As the plaque build ups) The artery becomes thicker, harder and less elastic.
The artery is then narrower and less able to stretch in response to blood flowing through it (so blood flow/oxygen to tissues is reduced).
Coronary atherosclerosis can be associated with what type of pain?
Chest pain on exertion that settles with rest
Blood pressure is an expression of arterial blood flow and what?
The peripheral resistance the blood encounters as
it flows round the body
What is total peripheral resistance and what happens to blood pressure when it increases?
The resistance the blood vessels offer to blood flow; the greater the resistance, the higher the blood pressure
Express Blood Pressure as a formula.
BLOOD PRESSURE = CARDIAC OUTPUT X TOTAL PERIPHERAL RESISTANCE
140-159/90-99 mmHg is classified as?
Stage 1 Hypertension
130-139/85-89 mmHg is classified as?
High normal - Pre-hypertension