Cardiovascular and Vessels Flashcards
What are the 3 Pericardial Layers?
- Visceral
- Parietal
- Fibrous
What are the 3 functions of pericardial layers?
- Protects and anchors
- Prevents overfilling
- Creates a relatively friction free environment
What pericardial layer is closest to the heart?
Visceral layer
What pericardial layer is in the middle?
Parietal layer
What pericardial layer is the outermost?
Fibrous layer
What is the myocardium?
Cardiac muscle layer forming the bulk of the heart
What is the endocardium?
Endothelial layer of the inner myocardial surface. Thin, smooth tissue that makes up the lining of the chambers and valves of the heart
What is the order of flow for Pulmonary Circulation, beginning with the Right Atrium?
1.Right atrium
2. Right AV valve (tricuspid)
3. Right ventricle
4. Pulmonary semilunar valve
5. Pulmonary trunk
6. Right and left pulmonary arteries
7. Pulmonary capillaries
8. Right and left pulmonary veins
9. Left atrium
What is the order of flow for Systemic Circulation, beginning with the Left Atrium?
- Left atrium
- Bicuspid valve (mitral)
- Left ventricle
- Aortic semilunar valve
- Aorta
- Systemic arteries
- Systemic capillaries
- Systemic veins
- Right atrium
What are the two distinct circulations?
Systemic and Pulmonary
What is the function of arteries?
Carry blood away from the heart
What is the function of capillaries?
Permit exchange
What is the function of veins?
Carry blood to the heart
What is Coronary Circulation?
The functional blood supply to the heart muscle itself
What is the function of intercalated discs on myocardial cells?
They anchor cardiac cells together and allow free passage of ions
What is the function of desmosomes?
Mechanically join cells with protein filaments
What is the function of Gap Junctions?
To electrically join cells (allow ion flow) to make each heart chamber a functional unit (functional syncytium)
Define the cardiac cycle.
The beginning of one beat until the beginning of the next beat, and everything that happens in between
What is systole?
Pumping/contraction
What is diastole?
Rest
What are the two basic types of cells in heart tissue?
Autorhythmic cells and muscle cells
What is the job of autorhythmic cells?
Their job is to just set the pace
What is the job of muscle cells?
They respond to the autorhythmic cells and contract.
What is the function of the Sinoatrial (SA) Node?
Pacemaker
What is the sequence of current flow through the heart wall (five steps)?
- SA node
- AV node
- AV bundle
- Bundle branches
- Pukinje fibers
Describe in detail the Electrical Control of Contraction (5 steps)
- SA node activity and atrial activation begin
- Stimulus spreads across the atrial surfaces and reaches the AV node
- There is a 100 millisecond delay at the AV node. Atrial contraction begins
- The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the purkinje fibers and via the moderator band, to the papillary muscles of the right ventricle
- The impulse is distributed by purkinje fibers and relates throughout the ventricular myocardium. Atrial contraction is completed and ventricular contraction begins.
What pace (in bpm’s) does the SA node set?
100 bpm