Chapter 6 Key Terms Flashcards
Circulatory System
System that consists of the cardiovascular system (heart, blood, and blood vessels) and the lymphatic system (lymph, lymph vessels, and nodes) and is the means by which oxygen and nutrients are carried to the cells and carbon dioxide and other wastes are carried away from them
Septa (Septum)
Partitions consisting mostly of myocardium that separate the right and left chambers of the heart
Pericardium
A thin fluid filled sac that surrounds the heart
Epicardium
The thin outer layer of the heart
Myocardium
The middle muscle layer of the heart
Endocardium
The thin inner layer of the heart
Atria (atrium)
The upper receiving chambers on each side of the heart
Ventricles
The lower pumping or delivering chambers on each side of the heart
Atrioventricular (AV) Valves
The valves at the entrance to the ventricles
Chordae tendineae
Thin threads of tissue that attach the atrioventicular valves to the walls of a the ventricles to help keep them from flipping back into the atria
Semilunar valves
Valves at the exits of the ventricles that are crescent shaped like the moon
Interatrial septum
The partition that separates the right and left atria
Interventricular Septum
The partition that separates the right and left ventricles
Coronary arteries
Arteries that branch off of the aorta just beyond the aortic semilunar valves that delivers blood to the heart muscle
Myocardial ischemia
Condition resulting from an insufficient supply of blood to meet the oxygen needs of the heart muscle
Myocardial infarction (MI)
Heart attack or necrosis (death) of heart muscle from lack of oxygen
Cardiac Cycle
One complete contraction and subsequent relaxation of the heart
Systole
Contracting phase of the cardiac cycle
Diastole
Relaxing phase of the cardiac cycle
Sinoatrial (SA)node or Pacemaker
Structure that generates the electrical impulse that initiates heart contraction
Electrocardiogram (ECG or EKG)
An actual record of the electrical currents that correspond to each event in heart muscle contraction
Murmurs
Abnormal heart sounds due to faulty valve action
Heart rate
Number of beats per minute, which is normally around 72 beats per minute in adults
Cardiac output
Volume of blood pumped by the heart in 1 minute and averages 5 liters per minute