Science Flashcards
pulmonary semilunar valve
prevents return of blood into right ventricle
bicuspid valve
aka mitral valve
prevents blood from entering left atrium when ventricle contracts
aortic semilunar valve
stops backflow of blood into left ventricle as it leaves thru aorta
bloodflow thru heart of right side
superior/inferior vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary valve -> pulmonary artery -> lungs
Right side = RIGHT to the lungs
bloodflow thru heart of left side
pulmonary veins -> left atrium -> mitral/bicuspid valve -> left ventricle -> aortic valve -> aorta -> body
endothelium
inner lining of blood vessels and lymphatic vessels
lines entire circulatory system composed of squamous endothelial cells connected by tight and adheren junctions
selectively permeable barrier b/w blood and larger molecules
releases peptides called endothelin that cause smooth muscle in vessel walls to contract for vasoconstriction
secrete chemicals that inhibit coagulation of blood
if damaged, the release different chemicals for blood clot formation
blood pressure
force per unit area that’s exerted by blood on walls of vessels
unless indicated, refers to pressure in major arteries
systolic pressure
max pressure exerted during systole
systole
when ventricles contract, forcing blood into aorta and pulmonary trunk
diastole
ventricles relax and BP is at lowest point
verage BP
120 systolic bp/ 80 diastolic bp
high bp
can damage walls of blood vessels and increase risk of heart disease, heart failure, and stroke
low bp
only risk if it occurs suddenly or causes lightheadedness or fainting
systemic circuit
carries blood from left ventricle -> aorta -> arteries -> arterioles -> capillary beds w/in tissue
longer than pulmonary circuit so it has higher blood pressure
blood in arteries carries more oxygen than blood in veins
when oxygen levels are low, vessels dilate to promote blood flow to tissues that need it
capillary beds
oxygen and nutrients eneter tissues
CO2 and other waste enter blood