Lab 2 Flashcards
What is the mediastinum?
Space occupied by the heart that sits in between lungs.
What is the pericardium?
Pericardium – fibrous sac surrounding heart.
What is the epicardium?
Epicardium – fibrous outer layer of heart.
What is the pericardial space?
Pericardial space – thin, water filled area between epicardium and pericardium that lubricates the heart as it contracts and relaxes.
What is the myocardium?
Myocardium – muscular layer of heart; mainly cardiac muscle cells.
What is the endocardium?
Endocardium – inner layer of heart.
What are the receiving and discharging chambers of the heart?
Atria is plural / atrium is singular.
Atria – receiving chambers.
Right atrium.
Left atrium.
Ventricles – discharging chambers.
Right ventricle.
Left ventricle.
What are the atrioventricular valves?
Atrioventricular valves
Tricuspid valve: between right ventricle and right atrium.
Bicuspid valve: between left ventricle and left atrium.
Helping to control atrioventricular valves are papillary muscles and chordae tendineae (strings).
What are the semilunar valves?
Semilunar valves
Pulmonary valve: discharge out of right ventricle.
Aortic valve: discharge out of left ventricle.
No papillary muscles or chordae tendineae to control semilunar valves.
Cusp – pocket-like structure of valves.
What is the SA node?
SA or sinoatrial node – “pacemaker” – generates action potentials (APs).
What are the internodal pathways?
Internodal pathway – pathway for some APs from SA node to AV node.
What is the AV node?
AV or atrioventricular node – entry point for APs from atria to ventricles.
What is the AV bundle?
AV bundle – APs coming out of AV node.
What are the bundle branches?
Bundle branches – AV bundle divides into right bundle branch for APs to right ventricle and left bundle branch for APs to left ventricle.
What are the purkinje fibers?
Purkinje fibers – coming off bundle branches for APs to ventricular cardiac muscle cells.
