RUSVM Physio Cardio Basic anatomy and cardiac muscle Flashcards
What are the 3 different types of cardiac cells
- Working Myocardial cells or myocardium
- Pacemaker cells
- Conduction cells
What are working myocardial cells or myocardium
Striated muscle specialized for contraction and impulse conduction
What are pacemaker cells
Cells that exhibit automatic rhythmical electrical discharge in the from of APs.
What are conduction cardiac cells
Cells that conduct the APs through the heart providing an excitatory system that controls the rhythmical beating
Why is the myocardium a functional syncytium?
They do not fuse into a single multinucleated fiber during embryonic development like skeletal muscle does. (morphological syncytium)
Describe intercalated disks
The intercalated disk is a dark, dense cross-band found in the end of each myocardial cell.
It is continuous with the sarcolemme and contains important cell-cell junctions.
What cell-cell junctions are in the myocardium
Gap-junctions and desmosomes
What do gap-junctions allow
- Allow rapid diffusion of ions
2. AP are able to travel easily from one cell to the next
What is the importance of desmosomes
They provide mechanical strength
What are the similarities between cardiac and skeletal muscle
- Fibers are striated
- Myofibrils are made up from actin and myosin filaments
- Contains SR and T-tubules
What are the differences between cardiac and skeletal and muscle.
- Contraction is involuntary
- Fibers are short and branched
- Usually uni nucleated
- Interconnected by intercalated disks.
What is the atrial and ventricles separated by
Atrioventricular Valves
What is the valve called between the left atrium and left ventricle
Mitral valve = Left AV Valve
What is the valve called between the right atrium and right ventricle
Tricuspid valve = Right AV valve
What are the valves called that are positioned between the ventricles and the great arteries
Semilunar valves
