Ch. 15 Flashcards
Blood vessels called ___ carry blood toward the heart, and ___ carry blood away from the heart
veins ; arteries
Why is the cardiovascular system vital to survival?
bring O and nutrients to all cells
What is a function of the pulmonary circuit?
sends O poor blood to lungs
What is a function of the systemic circuit?
carries O poor blood to the heart
During ventricular contraction, what is the status of the atrioventricular valves?
closed
Name the tough outermost layer of the sac that surrounds the heart?
fibrous pericardium
What forms the skeleton of the heart?
white fibrous connective tissue
What layer lines the chambers of the ehart?
endocardium
Name the layers of the wall of the heart and surrounding structures from deep to superficial?
endo, myo, epi, pericardial cavity, parietal pericardium, fibrous pericardium
Blood entering the right atrium comes from what structure?
vena cavae and coronary sinus
What is the function of atrial natriuretic peptide (ANP)?
increases exretion of NA and water , decreases blood volume
What happens in the condition called mitral valve prolapse?
cusps stretch into L atrium during ventricular contraction
The pain of angina pectoris results from a blockage in an artery that supplies what structure/area?
heart
What chambers of the heart will contain O poor blood?
R atrium, R ventricle
Which valve is located between the L atrium and L ventricle?
mitral valve
What is the correct sequence of components of the cardiac conduction system?
SA node, AV node, AV bundle, R&L bundle branches, veroingee fibers
What is the normal pacemaker of the heart?
SA node
What causes the P wave on ECG?
depolarazation of R atrial myocardium
What causes the T wave on ECG?
ventricular myocardiumO
n an ECG, the PQ interval indicates the time for a cardiac impulse to travel from the ___
SA node through the AV node
What term refers to an abnormally slow heart rate?
bradycardia
The ventricular walls and the atrial walls each form a functional syncytium. What does this mean?
mass of cells functioning as 1 unit
How does potassium affect heart rate?
electrical potential of cell membranes
What is released by the endothelium?
nitric oxide
What is the effect of nitric oxide in blood vessels?
vasodilation
P wave on ECG
atrial depolarization
QRS wave complex
ventricular depolarization
T wave
ventricular repolarization
In capillary beds, the net inward pressure at the venular ends of the capillaries is less than the net outward pressure at the arteriolar ends of the capillaries. What is the result of this difference in pressure?
more fluid leaves capillaries, than returns
What blood vessels hold the greatest volume of blood?
arteries
Why does fluid leave capillaries at their arteriolar end and enter at the venular end?
higher hydrostatic pressure at arieolar end
What does the Frank Starling law of the heart indicate
quantity of blood that enters the heart equals the amount that is pumped out
What is increased when sympathetic stimulation to the heart increases?
heart rate and stroke volume
What is preload?
amount of stretch of myocardial cells before contracting
What is the effect of vasoconstriction?
increased blood pressure
Plasma proteins contribute to the ___ pressure of the blood
osmotic
When is blood pressure in the large systemic arteries the greatest?
during ventricular systily
What helps to return blood to the heart
svc, ivc, skeletal muscle
How do you calculate stroke volume (SV)?
end diastolic volume - end systolic volume
How does angiotensin ll increase bp?
increased peipheral resistance
What structures contain chemoreceptors that monitor blood levels of O and carbon dioxide?
aortic bodiesTh
The pulmonary trunk divides into what 2 vessels?
R and L pulmonary arteries
changes due to aging of the cardiovascular system?
increased BP, Increased pulse due to tunica interna thicken and openings are smaller
Purpose of valves in veins and the heart
return blood to the heart and ensure 1 way blood flow
Function of the papillary muscles of the heart?
prevent prolapse of valvesD
ruing the cardiac cycle at the time of hightest ventricular pressure, what is the status of the heart valves?
AV closed, semilunar are open
What causes the first heart sound? When does this occur?
closure of atrioventricular valves at the beginning of ventricular cystily
What occurs in arteries that results in the disease called atherosclerosis?
buildup of plaque in artery
The ___ of the medulla oblongata send sympathetic signals to arteriolar smooth muscle, helping maintain peripheral resistance.
vaso motor center
Location of O poor blood?
systemic veins and pulmonary arteries
What happens that allows the SA nose spontaneously depolarize?
progressive increase in membrane permeability to Ca and NA. decrease in K
How is the hepatic portal system different from other circulatory vessels?
blood flows from capillary to veins to a 2nd set of capillaries to veins before coming back to the heart
