Cardiovascular System Lecture Flashcards
What makes up the cardiovascular system?
heart, blood vessels, and blood
What is the purpose of the cardiovascular system?
delivery and removal of substances
maintain homeostatis
What is the average number of beats per minute?
75
What is the right side pump? What is the left side?
Right=pulmonary
left= systemic
What is the path of blood in the pulmonary circuit in brief?
R heart -> pulmonary trunk -> pulmonary arteries -> pulmonary arteries -> pulmonary capillaries -> pulmonary veins -> L heart
Function of the fibrous pericardium?
most superficial, protective, restricts the size of the heart
What lies between the parietal and visceral layers and what is it filled with?
pericardial cavity and pericardial fluid
What are the three layers of the heart wall?
epicardium
myocardium
endocardium
What is another name for the epicardium?
visceral serous membrane
Function/structure of the myocardium?
majority of the thickness of the heart wall. Made of muscle tissues (cardiomyocytes) and provides the ability for the heart to contract
Structure/function of the endocardium?
Lines chambers of the heart, made of simple squamous endothelium which provides a smooth surface for blood movement
What are the 4 chambers of the heart?
right atrium, right ventricle, left atrium, left ventricle
What veins supply the right atrium?
Superior and inferior vena cava and coronary sinus
what veins supply the left ventricle?
the right and left pulmonary veins (4)
What are the three types of muscle structures inside the heart and along the heart walls?
trabeculae carneae, pectinate, and papillary muscles
What structures keep the AV valves closed?
chordae tendineae which connect to papillary muscles
List the blood flow through the heart and lungs
R atrium -> tricuspid valve -> R ventricle -> pulmonary semilunar valve -> pulmonary trunk + arteries -> lungs -> pulmonary veins -> left atrium -> bicuspid valve -> left ventricle -> aortic semilunar valve -> aorta
Structure and function of valves
Thin floppy tissue that opens and closes in response to pressure changes. Stop blood from flowing back.
Why does blood flow throughout the heart and lungs?
Pressure gradients
What causes the AV valves to open?
HIgher pressure in the atrium than the ventricles
What causes the SL valves to open?
Higher pressure in the ventricles than the arteries
What causes heart sounds and which valves cause which heart sounds?
The sound is created by valves closing
lub= AV valves closing
dub= SL valves closing
what is the importance of the coronary circuit?
provides blood to the heart tissue
what is an arterial anastomoses
alternate routes to get blood to the same portion of tissue
What two major arteries supply the myocardium with blood?
R and L coronary arteries which branch off the aorta
What is the major vein that removes blood from the myocardium?
coronary sinus
Describe atherosclerosis
Fatty plaques in the coronary artery that reduce blood flow to the myocardium
Describe a myocardial infarction
complete blockage of a coronary artery stopping arterial blood flow to heart tissue. Tissue death is permanent and causes scar tissue that does not contract
What are 6 cardiomyocyte properties
amitotic, uninuclear, striation, high number of mitochondria, high volume of myoglobin, and branching
What type of cell metabolism do cardiomyocytes use?
aerobic cellular respiration
What does the endomysium contain a lot of?
capillaries
Where do cardiomyocytes get their Ca2+?
80% from the sarcoplasmic reticulum
20% from extracellular fluid
What are the two types of cell junctions between cardiomyocytes and what are their functions?
intercalated discs (gap junctions)- conduct electricity and cell-to-cell communication
desmosomes- resist tension on the cells
What percentage of cells in the heart are contractile and what percentage are conductive?
99% contractile
1% conductive
What is the function of the conductive cells? What are some of their features?
Form the conduction system of the heart . They are self-excitable, autorhythmic, and create their own action potentials.