Structure of the heart Flashcards
(47 cards)
What are the three layers of the heart (from outermost to innermost)
- Pericardium
- Myocardium
- Endocardium
What is the function of the pericardium
To prevent the heart from over stretching and protect it from structural damage
What is the inner layer of the pericardium composed of
Two serous membranes
What do the serous membranes in the inner layer of the pericardium produce and what is the function of this
Serous fluid between the two layers to provide lubrication
What are the two layers of the pericardium
The parietal pericardium (outer)
The visceral pericardium (Inner)
What does the serous fluid between the two layers of the pericardium do
permits the membranes to move against each other without friction
What is the myocardium made of
thin filaments of actin and thick filaments of myosin (muscular layer)
What is the endocardium made of
single layer of epithelial cells continuous with the innermost layer of the blood vessels
What are the trabeculae cardneae
Rough muscle bundles that line the anterior and inferior walls of the right ventricle, lower two thirds of the septum and inferior walls of the right ventricle. Involved in contraction of the heart.
What helps the cardiac muscle to be fatigue resistant
The cells in the cardiac muscle contain a large number of mitochondria
what is cardiac muscle innervated through
The autonomic nervous system
What are the 4 chambers of the heart
The left and right atrium and the left and right ventricle
What is the pathway of blood flow through the heart
Superior and inferior vena cava sends deoxygenated blood from the body to the right atrium.
Blood flows through the tricuspid valve into the right ventricle.
Blood is pumped through the pulmonary valve into the pulmonary trunk which divides into right and left pulmonary arteries.
Deoxygenated blood is taken into the lung for gaseous exchange.
Capillaries bring oxygenated blood into pulmonary venules and pulmonary veins.
Veins empty into the left atrium of the heart where the blood is pumped through the bicuspid valve to the left ventricle.
From the left ventricle, blood is pumped through the aortic valve into the aorta and then out to the body through the arteries, arterioles and capillaries.
What divides the left and right sides of the heart.
The septum
What is the role of the valves of the heart
Ensure blood flows in one direction, from the atria to the ventricles, while preventing back flow from the ventricles into the atria
What are the valves between the atria and ventricles
atrioventricular valves
What are the two atrioventricular valves
tricuspid (right side of heart) bicuspid (left side of heart)
What are the valves at the entrances to the major arteries from the heart
semilunar valves (pulmonary valve and aortic valve)
What is the function of the valves during blood flow through the heart
When the ventricles relax, the semilunar valves close and the atrioventricular valves open, allowing blood to move from the atria into the ventricles.
Once the ventricles contract, the atrioventricular valves close and the semilunar valves open, ensuring that blood moves from ventricles to pulmonary trunk and aorta and not back into atria.
What circulatory system supplies blood to the heart itself
coronary circulation
What is the blood supply to the lungs
the pulmonary circulation
what is the blood supply to the rest of the body
the systemic circulation
What happens in the pulmonary circulation
pulmonary arteries carry deoxygenated blood from the heart to the lungs to be oxygenated, which is carried back to the heart by the pulmonary veins
What happens in systemic circulation
Arteries carry oxygenated blood from the heart to the rest of the body to be used by the cells, and the deoxygenated blood is carried back to the heart by the veins.
