A&P CH12 Flashcards
flow of blood through the heart
right atrium tricuspid valve right ventricle pulmonary valve lungs left atrium bicuspid valve left ventricle aorta body right atrium
which side of heart is larger? why?
left, it needs to generate more force
heart located where?
mediastinum
def pericardium
surrounds the heart
2 layers of pericardium, and name for first
visceral lines heart (also called epicardium), parietal lines pericardial cavity
def auricle
lumpy, wrinkled flap
3 layers of heart
epicardium (outer)
myocardium (muscle)
endocardium (inner)
which layer of heart contains vessels?
myocardium
which layer of heart is smooth epithelium?
endocardium
what do gap junctions do?
allow action potentials to move rapidly between cells
what divides 2 atria?
interatrial septum
what divides 2 ventricles?
interventricular septum
what does coronary circulation do?
circulates blood to the heart muscle
def anastomoses
alternate pathways for blood flow, assist in blockage situations
which cells form bulk of heart’s muscle tissue?
contractile
steps to contraction (3)
- rapid depolarization
- plateau
- repolarization
why separate firing mechanisms?
backup system to ensure cardiac operation if one part fails
def SA node
cardiac pacemaker, electrical signal generated here
how fast does SA fire?
70-80 bpm
how fast does AV fire?
40-60 bpm
how fast do purkinje fibers fire?
20-40 bpm
what is the p wave?
caused by depolarization of atria, sa node firing causes a contraction in atria
what does QRS complex show?
action potential traveling through ventricles
what does T wave show?
ventricular repolarization
