Ch. 18- The Heart Flashcards
Take blood away from the heart
Arteries
Bring blood back to the heart
Veins
The smallest blood vessel. Functions in gas exchange and distributing nutrients
Capillaries
The region between the pleural sacs; contains the heart and all of the thorax except the lungs
Mediastinum
What is the largest blood vessel?
Aorta
What layer prevents overfilling of the heart with blood?
Fibrous pericardium
What 2 layer membrane contains the pericardial fluid in between?
Serous pericardium
What is the role of the pericardial fluid?
Allows the heart to beat without friction
Inflammation of tissues around the heart
Pericarditis
What is the average heart rate in a person?
75 beats/min
What are the three layers of the heart?
Epicardium
Myocardium
Endocardium
Prevents backflow into atria during ventricular contraction
Atrioventricular valves
Prevents backflow from aorta and pulmonary trunk into the ventricles
Semilunar valves
Proteins that pull cell together tightly
Desmosomes
Allow ions to pass from one cell to another
Gap Junctions
Links one cell to the next via actin myofilaments
Mechanical junctions
Oxygen storage molcule
Myoglobin
Systole is…
Contraction
Diastole…
Relaxation
Heart Rate=
Systole/Diastole
Normal heartbeat is triggered by what?
Sinoatrial node
Normal heartbeat is also referred to by
The Sinus Rhythm
How long is the cardiac cycle?
0.8 seconds
What is the pacemaker of the heart?
Sinoatrial node
True or False.
Myocytes are autorhythmic
True