The Heart Flashcards
What are the three distinct layers of the walls of the heart?
the epicardium, the myocardium, and the endocardium
What is the epicardium?
the outermost layer of the wall of the heart that interacts with the pericardium and reduces friction
What is the myocardium?
the thickest layer of the heart wall that is most commonly thought of when you imagine the walls of the heart
What does the myocardium consist mostly of?
cardiac muscle that helps us pump blood out of the heart chambers
What is the endocardium?
the innermost layer of the walls of the heart
What is the endocardium made up of?
elastic tissue, blood vessels, and specialized cardiac muscle fibers
What does the pericardium do?
encloses the heart but leaves the large blood vessels uncovered
What is the right atrium?
the top right chamber of the heart that receives unoxygenated blood from the rest of the body
What does the tricuspid valve possess?
three large projections called cusps
Where does the tricuspid valve lie?
between the right atrium and right ventricle
What does the tricuspid valve do?
allows blood to flow between the right atrium and right ventricle, and prevents backflow when the right ventricle contracts
What is the right ventricle?
the empty chamber of the heart on the lower right that receives unoxygenated blood from the right atrium
What does the right ventricle do?
contracts and sends the blood out of the heart and into pulmonary arteries so it may be oxygenated by the lungs
Where does the pulmonary valve lie?
between the right ventricle and the pulmonary artery
What does the pulmonary valve do?
it allows the blood to flow from the right ventricle to the pulmonary artery and it prevents backflow
What does the pulmonary artery do?
it transports unoxygenated blood from the right ventricle to the lungs so it can become oxygenated
What do the pulmonary veins do?
carry newly oxygenated blood from the lungs to the left atrium
What does the bicuspid/mitral valve do?
allows oxygenated blood to flow from the left atrium to the left ventricle, prevents backflow
What does the left atrium do?
receives oxygenated blood from the pulmonary veins and passes it on to the left ventricle
What does the left ventricle do?
receives oxygenated blood from the left atrium via the bicuspid valve
What is the left ventricle responsible for?
pumping blood out of the heart and to the rest of the body via the aorta
What cavity of the heart has the most muscle mass?
the left ventricle
What does the aortic valve do?
opens up to allow oxygenated blood to leave the heart and enter the aorta, prevents backflow
What is one of the biggest blood vessels in the body?
the aorta
What is the aorta responsible for?
distributing blood from the heart to the rest of the body
What does the aorta break down into?
smaller major arteries and goes to the rest of the body
What do the first two branches of the aorta do?
supply blood to the tissues of the heart
What happens when atria contract?
ventricles relax
What is a heart contraction called?
systole
What is a heart relaxation called?
diastole
What does the heart contract in?
patterns
What causes heart sounds?
vibrations that occur when valves are closed
In lubb-dupp (your heartbeat), what is lubb?
the sound that occurs during ventricular contraction when the tricuspid and mitral valves close
In lubb-dupp (your heartbeat), what is dupp?
the sound that occurs when the ventricles relax and the pulmonary and aortic valves close
What are arteries?
strong elastic vessels that are used to carry blood away from the heart
What does the smooth muscle in the walls of arteries allow the arteries to do?
vasoconstrict and vasodilate
What happens during vasoconstriction?
the smooth muscle contracts and decreases the diameter of the artery
What happens during vasodilation?
the smooth muscle relaxes and increases the diameter of the artery
What are arterioles?
subdivisions if arteries that are finer/thinner and more branch-like
What do veins do?
carry blood from the body back to the heart
Is blood in veins oxygenated or deoxygenated?
deoxygenated, which is why it has a purple tone to it
What do veins possess?
flaps that block backflow from occurring
In comparison to arteries, do veins have more or less muscle?
less, and they also have thinner walls
What can the walls of veins do?
dialate and contract
What are venules?
smaller portions of veins that connect them to capillaries
What are capillaries?
the smallest diameter blood vessels
What do capillaries do?
connect arterioles and venules
What do the thin walls of capillaries do?
form semi permeable membranes so particles in the blood can be exchanged for those in the surrounding tissue
What kind of tissue has many capillaries in it?
tissue that has a high metabolism and needs a lot of nutrients, such as muscle and nerve tissue
