Cardiac Muscle Flashcards
myocardial fibers are separated by _________
Sarcolemma
Junctions of branching fibers are specialized areas ________ that contain many gap junction
Intercalated discs
Electrical synapse through which wave of _______ can easily pass from cell to cell
Gap junctions; depolarization
_____ acts as a single unit
Synctial tissues
2 synctia in heart
- ______ syncytium
- _______ syncytium
Atrial, ventricular
_______ are completely separated from ________ by a fibrous band of tissue called _______
Atria, ventricles, Atrioventricular ring
Fundamental unit of myocyte contraction, defined as distance between _______
Sacromere, Z-lines
In skeletal muscles, ________ of cardiac muscle occurs by __________ mechanism
Shortening, sliding filament
Z-lines are pulled closer during _____ and move further apart during _______
Contraction, relaxation
Skeletal muscles contain ___ mitochondria whereas cardiac muscles are _____ in mitochondria which allows them rapid oxidation to produce ______
Few, rich;
ATP
- This consists of T-tubules and SR.
- T-tubules are present as deep invagination of ______ into muscle fibers at Z-line, present in ______ junction in skeletal muscle.
- T-tubules are **more developed”* in _____ myocytes than in atrial myocytes
- SR + T tubular system forms a _____ that contains 1 _______ and 1 ______ and _____ in skeletal system
1.Sarcotubular system;
2.Sarcolemma, A-I junction;
3. Ventricular
4. Diad, t-tubule, cistern; triad
Length-tension relationship
Active force developed is maximum within the _______ length
Determines the max number of cross-bridges that can form therefore determines the maximum tension or __________
Optimal;
Sacromere length, force of contraction
Length-tension relationship
Increase in ______ of sacromere increases the sensitivity of the myofilaments to ________
Stretch of ______ increases the affinity of ________ to Ca2++ whoch eventually allows muscle contraction
Length, Ca2++;
Myocardium, troponin C
