Anatomy of cardiovascular system Flashcards
Apex
Lowest part of the heart from by left ventricle. Projects at 5th intercostal space
Base
Upper border of the heart involving LA, part of RA. Lies below second rib.
Endocardium
inner lining of the hearts chambers and its valves
Epicardium
visceral layer of serous pericardium. contains epicardial coronary arteries and veins, autonomic nerves, and lymphatics
Myocardium
muscular, middle layer of the heart
Pericardium
Double-layered membrane surrounding the heart.
What areas do the right coronary artery supply?
RA, RV, sinus node artery, right marginal artery, post. descending artery, inferior wall of both ventricles
What areas do the left coronary artery supply?
LA, post.lat walls of LV, ant.inf walls of LV, circumflex artery
What is the normal pacemaker of the heart?
sinoatrial (SA) node
What forms the common bundle of His?
AV node
What does the common bundle of His branch into?
Purkinjie fibers
baroreceptor reflex
The primary reflex pathway for homeostatic control of blood pressure
Bainbridge reflex
An increase in venous return stretches receptors in the wall of the right atrium which sends vagal afferent signals to the cardiovascular center within the medulla. The signals inhibit parasympathetic activity, resulting in an increased heart rate
Chemoreceptor reflex
Chemosensitive cells located in the carotid bodies and the aortic body respond to changes in pH status and blood oxygen tension.
Valsalva maneuver
forcible exhalation against a closed glottis, resulting in increased intrathoracic pressure, increased central venous pressure, and decreased venous return. The resultant decrease in CO and BP is sensed by baroreceptors which then increase HR.
What is the cardiac cycle?
sequence of events that occur when the heart beats
Atrial systole
contraction of atria pumps blood into the ventricles
ventricular systole
contraction of ventricles pumps blood into aorta and pulmonary arteries
atrial dystole
the period between atrial contractions when the atria are repolarizing
preload
Tension in the ventricular wall at the end of diastole. Reflects the venous filling pressure that fills the left ventricle during diastole
Stroke Volume (SV) and normal ranges
The volume of blood ejected with each left ventricular contraction. Normal ranges between 60-80ml
Cardiac Output (CO)
Amount of blood pumped from the left or right ventricle per minute. Equal to the product of SV and HR.
Normal values: at rest: 4.5 to 5.0 L/min. During exercise: 25 L/min
Venous return
the amount of blood that returns to the right atrium each minute
Afterload
the amount of resistance to ejection of blood from the ventricle
