Circulation Flashcards
What are the two parts of the circulatory system?
Systemic and pulmonary
What does the pulmonary system do?
moves blood between the heart and the lungs.
What does the systemic system do?
moves blood between the heart and the body tissues other than the lungs.
Describe the make up of the heart
The heart is enclosed in a membrane to protect it against friction. It consists of four chambers, two atria and two ventricles.
What is the membrane which surrounds the heart called?
Pericardium
The wall of the heart consists of three layers. The outer layer is the epicardium
This is the thin transparent outer layer of the wall
What is the middle layer of the hearts wall?
The middle layer is the myocardium. It is composed of cardiac muscle tissue and makes up the bulk of the heart. It is responsible for the heart’s pumping action
What is the inner layer of the wall of the heart called?
The inner layer is the endocardium. This is a thin layer of flat cells that provides a smooth lining for the chambers of the heart and covers the heart valves.
What do the left and right sides of the heart do?
The right side of the heart takes oxygen-depleted blood from the body and passes it to the lungs.
The left side takes in oxygen-rich blood from the lungs, and passes it back to the body
Describe the oxygenation process in the heart
The oxygen depleted blood travels from the body to the lungs, through the right ventricle through the pulmonary artery to the lungs, where carbon dioxide is exchanged for oxygen. The oxygenated blood is returned to the left atrium of the heart, through the pulmonary veins
How many valves does the heart have?
4
What are the two stages of a heartbeat?
Contraction (systole) and relaxation (diastole)
What happens during the ‘diastole’ relaxation phase of a heartbeat?
All four valves are closed, blood is drawn into the left atrium from the lungs and to the right atrium from the body. The pressure of the blood in the heart then opens the respective valves, the atriums contract and ensure all the blood is squeezed out.
What happens during the ‘systole’ contraction phase of a heart beat?
The heart muscle contracts and the blood in the right ventricle travels down the pulmonary valve to the lungs, the blood in the left ventricle travels down the aortic valve and out to the body.
Q: What are enzymes and how do they function in chemical reactions?
A: Enzymes are organic catalysts that release and transfer energy by increasing the rate of a chemical reaction without being consumed in the process.
