Cardiovascular System Flashcards
What does Cardio refer to?
The Heart
What does Vascular refer to?
Blood vessels
What makes up the cardiovascular system?
heart
vessels
arteries
capillaries
veins
What role does the cardiovascular system play in the body?
It supplies oxygen and nutrients to tissues and it removes wastes from them.
Describe the heart
Hollow, cone-shaped, muscular pump within the thoracic cavity
The average adult heart is 14cm long and 9cm wide
The heart consists of 3 layers, what are they?
Epicardium - Outer protective layer
Myocardium - Muscular layer
Endocardium - A thin inner later
What is the epicardium made of?
it is made up of connective tissue and epithelium
It houses blood and lymph capillaries along with coronary arteries.
What is the Myocardium made of?
Consists of cardiac muscle and is the thickest layer of the heart wall.
What is the endocardium made up of?
It is a thin, smooth layer made up of connective tissue and epithelium.
What are do arteries do?
carry blood away from the heart
What do veins do?
They carry blood back to the heart.
The heart has 4 chambers and 4 valves. What are the 4 chambers called?
The heart has 2 atria on top which receives blood returning to the heart. They have thin walls.
It has 2 ventricles below which pump blood to the body. They have thick-muscled walls
What separates the left and right sides of the heart?
The septum divides the atrium and ventricle on each side.
Atrial septum and Ventricular septum
What are the valves that separate the atrium from the ventricles called?
atrioventricular (A-V) valves
They ensure one-way flow of blood.
What are cusps?
flaps
What are chordae tendinae?
“cords” that connect the heart valves to the papillary muscle in the inner heart which contract to prevent (backflow) the flow of blood from the ventricle to the atrium
Describe the Right A-V valve
is it a tricuspid (3) valve between the Right Atrium and the Right Ventricle. It is a one-way valve from the atrium to the ventricle.
Describe the Left A-V valve.
It is a bicuspid (2) or mitral valve between the left atrium and the left ventricle. It is a one-way valve that allows blood to flow from the atrium to the ventricle.
Describe the Right Ventricle
it has a thinner wall than the left ventricle because it must pump blood only as far as the lungs.
What is the pulmonary valve?
it is the valve at the trunk of the pulmonary artery. It prevents the backflow of blood into the right ventricle.
Describe the left ventricle
It has a thicker wall than the right ventricle because it pumps blood to the entire body.
What is the aortic valve?
It is the valve at the trunk of the aorta. It prevents the backflow of blood into the left ventricle.
Describe the path of blood through the right side of the heart
Blood low in O2 returns to the right atrium via the vena cavae and coronary sinus
the right atrium contracts, forcing blood through the tricuspid valve into the right ventricle.
The right ventricle contracts, closing the tricuspid valve, and forcing blood through the pulmonary valve into the pulmonary trunk and arteries
The pulmonary arteries carry blood to the lungs where it can rid of excess CO2 and pick up a new supply of O2
Describe the path of blood through the left side of the heart
Freshly oxygenated blood is returned to the left atrium of the heart through the pulmonary vein
The left atrium contracts, forcing blood through the bicuspid valve into the left ventricle
The left ventricle contracts, closing the bicuspid valve and forcing open the aortic valve as blood enters the aorta for distribution to the body
The aorta is the largest blood vessel in mammals
How does the heart get its blood supply?
The first branches off the aorta, which carry freshly oxygenated blood are the right and left coronary arteries that feed the heart muscle itself.
The heart muscle requires a continuous supply of freshly oxygenated blood so smaller branches of arteries often have alternate pathways for blood in case one pathway becomes blocked.
What do cardiac veins do?
They drain blood away from the heart muscle and carry it to the coronary sinus which empties into the right atrium.
Describe the heart sounds
The first sound (lubb) occurs as ventricles contract. A-V valves are closing
The second sound (dubb) occurs as ventricles relax and aortic and pulmonary valves are closing
The sounds are due to vibrations in heart tissues as the blood rapidly changes velocity within the heart.
