Cardiovascular System Flashcards
Arteries
Vessels that carry blood away from the heart.
Blood vessels
A closed system of blood vessels, these vessels include arteries, capillaries, and veins.
Capillaries
Tiny vessels that branch off from arteries to deliver blood to all body tissues.
Deoxygenated
Deoxygenated blood (pulmonary): body → right chambers of the heart → lung
Heart
A muscular pump that forces blood around the body.
Oxygen
Tasteless gas essential to living organisms, being taken up by animals, which convert it to carbon dioxide
Oxygenated
Oxygenated blood (systemic): lung → left chambers of the heart → body
Pulmonary circulation
The pulmonary circulation, between the heart and lungs, transports deoxygenated blood to the lungs to get oxygen, and then back to the heart.
Systemic circulation
The systemic circulation carries oxygenated blood away from the heart to the tissues and cells, and then back to the heart.
Veins
Vessels that bring blood back to the heart.
Size of heart
About the size of a fist and shaped like an upside-down pear, the heart lies directly behind the sternum.
How many chambers does the heart have?
It has four chambers.
Location of heart
The heart is located in the mediastinum in the center of the chest cavity; however, it is not exactly centered; more of the heart is on the left side of the mediastinum than the right.
Apex
The tip of the heart at the lower edge is called the apex.
Endocardium
The endocardium is the inner layer of the heart lining the heart chambers. It is a very smooth, thin layer that serves to reduce friction as the blood passes through the heart chambers.
Myocardium
The myocardium is the thick, muscular middle layer of the heart. Contraction of this muscle layer develops the pressure required to pump blood through the blood vessels.
Pericardium
The heart is enclosed within a double-layered pleural sac, called the pericardium.
Atria
The atria are the receiving chambers of the heart. Blood returning to the heart via veins first collects in the atria.
Ventricles
The ventricles are the pumping chambers. They have a much thicker myocardium and their contraction ejects blood out of the heart and into the great arteries.
Tricuspid valve
An atrioventricular valve (AV), meaning that it controls the opening between the right atrium and the right ventricle. Once the blood enters the right ventricle, it cannot go back up into the atrium again. This valve has three (tri) leaflets or cusps.
Pulmonary valve
A semilunar valve, with the prefix semi- meaning half and the term lunar meaning moon, indicates that this valve looks like a half-moon. Located between the right ventricle and the pulmonary artery, this valve prevents blood that has been ejected into the pulmonary artery from returning to the right ventricle as it relaxes.
Mitral valve
Also called the bicuspid valve, indicating that it has two cusps. Blood flows through this atrioventricular valve to the left ventricle and cannot go back up into the left atrium.
Aortic valve
A semilunar valve, located between the left ventricle and the aorta. Blood leaves the left ventricle through this valve and cannot return to the left ventricle.
Blood Pressure
Blood pressure (BP) is a measurement of the force exerted by blood against the wall of a blood vessel.
Pulse
The pulse (P) felt at the wrist or throat is the surge of blood caused by the heart contraction. This is why pulse rate is normally equal to heart rate. Therefore, to see the full range of what is occurring with blood pressure, both numbers are required.
