cardiovascular system Flashcards
What is coronary circulation?
Supply of oxygen rich blood to the heart tissue
Which arteries supply the heart with blood?
right coronary artery
left coronary artery
Where do the coronary arteries branch from?
aorta
What is the heart?
muscular pump that keeps blood flowing through the vessels
What do vessels do?
Deliver blood to the body and then return it back to the heart
What is the pulmonary circuit?
right side of the heart
carries O2 poor blood to the lungs for gas exchange and then returns it to the heart
What is the systemic circuit?
left side of the heart
carries O2 rich blood to the body and returns O2 poor blood back to the heart
What is coronary circulation?
Hearts blood supply - O2
What are the three layers of the heart wall?
endocardium
myocardium
epicardium
Endocardium
innermost lining
simple squamous epithelium overlying a thin layer of loose Ct
continuous with the inner lining of blood vessels
Myocardium
cardiac muscle
thickest layer
Epicardium
simple squamous epithelium overlying a thin layer of loose CT
What is systole?
contraction
What is diastole?
relaxation
What are the major branches off the aorta?
brachioceohalic artery: right subclavian artery and right common carotid artery
left common carotid artery
left subclavian artery
Embryological development of the heart
The heart forms from an embryonic tissue called mesoderm around 18 to 19 days after fertilization.
When does the heart start beating?
22 days after conception or 5 weeks and 1 day gestation
What are the three layers of blood vessels?
Tunica intima, Tunica media, and Tunica externa
Characteristics of the tunica intima
consists of an inner surface of smooth endothelium covered by a surface of elastic tissues
Characteristics of the tunica media
made up principally of smooth (involuntary) muscle cells and elastic fibres arranged in roughly spiral layers.
Characteristics of the tunica adventitia
a constitutes the outermost layer of connective tissues
provides the shape, strength, and support for arteries and veins.
What are the 4 valves of the heart?
aortic valve, mitral valve, pulmonary valve and tricuspid valve
What are the different circuits of the heart?
Pulmonary Circulation and Systemic Circulation
The walls of which ventricle is thicker?
The left ventricle is thicker than the right ventricle because the left ventricle pumps oxygenated blood around the entire body
Action potential of the heart
electrical changes in the heart’s membrane that trigger the heart’s contraction and relaxation
Conduction in the heart
the network of signals that keeps your heart beating
What are the phases of the cardiac cycle?
Atrial systole
Ventricular systole
Atrial diastole
Ventricular diastole
Atrial systole
The atria contract and push blood into the ventricles
Ventricular systole
The ventricles contract and pump blood out of the heart
Atrial diastole
The atria relax and fill with blood
Ventricular diastole
The ventricles relax and fill with blood
What is the average stroke volume at rest?
50 to 100 ml.
How is heart rate changed?
adapts to our body’s need for energy throughout the day
Isovolumetric contraction
contraction of a closed ventricular chamber without a change in volume
Ventricular ejection
the ventricles eject blood to the body (through the aorta) and to the lungs (through the pulmonary artery).
Isovolumetric relaxation
the time immediately after ventricular contraction when the aortic valve has closed, but the mitral valve has not yet opened
Ventricular filling
the high pressure from the blood vessels forces blood into the expanding ventricle.
