Cardiovascular System Flashcards
The cardiovascular system is responsible for what?
It is responsible for transporting metabolites to and from tissues; regulates blood flow mainly by altering the capacity of the vasculature and volume of blood it holds.
What is Afterload?
It is the load against which an activated muscle must try to shorten; greater afterloads result in lower velocities.
What are Baroreceptors?
They are pressure-sensitive nerve endings in the walls of the atria of the heart, the vena cava, the aortic arch, and the carotid sinus.
What is Cardiac Output?
The volume of blood pumped per minute by the heart.
What is Cardiac Tamponade?
Compression of the heart caused by the collection of blood, fluid, or gas under pressure in the pericardium.
What are Chemoreceptors?
Sensory nerve cells activated by changes in the chemical environment surrounding it; the chemoreceptors in the carotid artery are sensitive to PCO2 in the blood, signaling the respiratory center in the brain to increase or decrease ventilation.
What is congestive heart failure?
An abnormal condition that reflects impaired cardiac output, caused by MI, ischemic heart disease, or cardiomyopathy.
What is Contractility?
Property of muscle tissue to shorten in response to a stimulus, usually electrical.
What is End-diastolic volume (EDV)?
The volume of blood remaining in the ventricles just prior to contraction.
What is End-systolic volume (ESV)?
The volume of blood in the ventricles at the end of contraction (systole).
What is negative inotropism?
A decrease in contractility of the heart.
What is the pericardium?
The fibrous, serous sac that surrounds the heart and roots of the great vessels.
What is positive inotropism?
An increase in the contractility of the muscle tissue.
What is Preload?
The pressure stretching the ventricular walls at the onset of ventricular contraction.
What is Stenosis?
The narrowing of a valve or vessel.
What is Stroke Volume?
The volume of blood ejected by the left ventricle during each contraction.
What is vasoconstriction?
The narrowing of the blood vessels.
What is vasodilation?
The widening or distension of blood vessels, particularly arterioles, usually caused by nerve impulses or certain drugs that relax smooth muscle in the walls of the blood vessels.
What are the two major subdivisions of the vascular system?
The systemic vasculature and pulmonary vasculature.
What are the three major components of the systemic vasculature?
Arterial system, capillary system, and venous system.
What are the four mechanisms that aid in venous return to the heart?
(1) Sympathetic venous tone
(2) Skeletal muscle pumping
(3) Cardiac suction,
(4) Thoracic pressure differences caused by respiratory efforts.
What is an anatomic shunt?
Whenever venous blood mixes with arterial blood the overall oxygen count decreases.
The atrioventricular valves close during what?
It closes during systole (contraction of the ventricles), preventing backflow of blood into the atria. Closure of these valves provides a critical period of isovolumic contraction, during which chamber pressures quickly increase just before ejection of the blood.
What is the capillary system?
Microcirculation maintains a constant exchange of nutrients and waste products for the cells and tissues of the body.
What are some common valve problems?
Regurgitation and stenosis.
What is conductivity?
The ability of myocardial tissue to spread, or radiate electrical impulses.
What is contractility?
In response to an electrical impulse is the primary function of the myocardium.
What is the coronary sinus?
Passes left to right across the posterior surface of the heart. The coronary sinus empties into the right atrium between the opening of the inferior vena cava and the tricuspid valve.
