Heart And Circulatory System Flashcards
What are the 3 distinct layers of the heart wall?
Epicardium (outer)
Myocardium (middle)
Endocardium (inner)
What separates the right and left ventricle?
Thick interventricular septum
What separates the right and left atria?
Thin interatrial septum
The right atrium receives what type of blood and from where?
Deoxygenated/venous blood from the superior and inferior vena cava
When blood travel from the right atrium to right ventricle, which valve does it pass through?
Tricuspid valve
From the right atrium, which valve does the blood travel through and where does it end up?
Blood travels through tricuspid valve into right ventricle. Then travels through the pulmonary valve and enters the right and left pulmonary arteries. The deoxygenated blood then travels to the lungs for gas exchange.
Where does oxygenated blood enter the heart?
From the lungs, through the left and right pulmonary veins and into the left atrium
Which valve connects the left atrium and the left ventricle?
Mitral (bicuspid) valve - oxygenated blood travels through this
From the left ventricle, how does the oxygenated exit the heart?
Through the aortic semilunar valve, the aorta, and to the rest of the body
What is the cardiac cycle of deoxygenated blood through the heart?
- Enters through superior and inferior vena cava to the right atrium
- Deoxygenated blood leaves the right atrium through the tricuspid valve into the right ventricle
- Blood exists the right ventricle through the pulmonary valve and exists the heart through the left and right pulmonary arteries
- The deoxygenated blood then travels to the lungs for gas exchange.
What is the cardiac cycle of oxygenated blood through the heart?
- Enters the left atrium through the left and right pulmonary veins
- Oxygenated blood travels through the mitral (bicuspid) valve into the left ventricle
- Exists the left ventricle through the aortic semilunar valve into aorta.
- The oxygenated blood then travels to the rest of the body.
What is the period of diastole in the cardiac cycle
A period of relaxation in the cardiac cycle when the heart fills with blood.
80% of blood flows directly through the atria into the ventricles before contraction.
What is the systole period in the cardiac cycle?
The phase of contraction of the hearts ventricles, forcing blood out of the heart.
Which valve will close during systole of the left ventricle?
Mitral valve will close to prevent back flow into left atrium
Which valve will close during systole of the right ventricle?
Tricuspid valve will close to prevent back flow into right atrium
Which ventricle has thicker walls and why?
Left ventricle due to the increased pressure required to pump blood to rest of body.
Which valve prevents back flow from the aorta into the left ventricle?
Aortic semilunar valve
What is pericarditis?
Inflammation of the pericardial sac
How many pints of blood does the heart pump 24/7?
8 pints
What encloses and protects the heart and forms the wall of the pericardial cavity which contains the pericardial fluid?
Pericardial sac / Parietal pericardium
What is the parietal pericardium composed of?
Outer fibrous and inner serous layer
Which layer of the parietal pericardium secretes the pericardial fluid and what is its function
Inner serous layer
Pericardial fluid acts to reduce friction as the heart beats
Which layer of the heart wall is responsible for contraction?
Myocardium; thick middle layer, composed of thick cardiac muscle
What is endocarditis?
Inflammation of the endocardium (smooth inner layer of the wall, lining of heart and internal structures.
What can endocarditis be triggered by?
Very rare; but bacteria can enter the blood stream through the mouth and then end up in the heart