Chapter 1 Structures Flashcards
Lower tip of left ventricle
Apex of the heart
Tough, inelastic and outer connective tissue
Fibrous pericardium
Two functions of the pericardium
1) Anchoring in place (attached to the diaphragm)
2) Prevents the heart from over stretching
Two parts of the pericardium
1) Fibrous pericardium
2) Serous pericardium
Thinner, delicate and forms double layer around heart
Serous pericardium
Fused to fibrous pericardium
Parietal layer
Adheres tightly to the heart
Visceral layer (epicardium)
Three layers of the heart
1) Epicardium
2) Myocardium
3) Endocardium
What layer of the heart forms two separate networks via gap junctions and intercalated disks: Atrial and Ventricular
Myocardium
Lines the inside of myocardium and covers valves
Endocardium
Four chambers of the heart
2 Atria and 2 ventricles
What separates the chambers of the heart
Interatrial and interventricular septum
How many valves are in the heart?
4
Two atrioventricular valves
1) Tricuspid valve
2) Bicuspid valve (also known as mitral valve)
What connects to papillary muscles on the ventricle side that prevents valve cusps from pushing up into the atria when ventricles contract?
Chordae tendineae
Drain deoxygenated blood from the upper and lower body into the right atrium
Superior and inferior vena cava
Drains deoxygenated blood from the coronary veins into the right atrium
Coronary Sinus
Blood is pumped from the right atrium to the right ventricle to:
Pulmonary trunk which then branches into the pulmonary arteries
Carries oxygenated blood from the lungs and transports it to the left atrium
Pulmonary veins
Carries oxygenated blood to the entire body from the left ventricle
Aorta
Blood that flows through the myocardium
Coronary circulation
Collects the heart’s deoxygenated blood and returns it to the right atrium
Coronary sinus
Where does cardiac excitation begin?
Sinoatrial (SA) node
What does the SA node stimulate?
1) Atria (via Bachmann’s bundle) causing contraction
2) Atrioventricular (AV) node
3) AV bundle branches (Bundle of his)
4) Right and left bundle branches
5) Purkinje fibers
ECG wave that represents atrial depolarization
P wave
ECG, wave that represents ventricular depolarization
QRS Complex
ECG wave that represents ventricular repolarization
T wave
Typical cardiac cycle (one heartbeat) is how long?
0.8 seconds
Three phases in a cardiac cycle
1) Atrial Systole
2) Ventricular Depolarization/systole
3) Ventricular Repolarization/relaxation
Relaxation period is noted as what wave on an ECG?
T wave
Atrial systole is noted on an ECG as what wave?
P wave
Ventricular systole is noted on the ECG as what wave?
QRS complex
How much blood is ejected into circulation per pump?
70 ml
The amount of blood ejected from the left ventricle into the aorta per minute
Cardiac Output (CO)