Card Set Information
Stabilizes thick ﬁlament lattice
Thicker in Type I vs. Type II
-Creatine Kinase (CK) ~2% Enzyme catalyzes rxn of PCr + ADP → ATP
-CK mostly soluble and associated c H-band
Smooth Muscle Organization
1. Whole muscle (epimysium) belly
2. Muscle Fascicle (perimysium) Bundle of muscle ﬁbers
3. Muscle Fiber (endomysium/ sarcolemma)Muscle cell
4. MyoﬁbrilSarcomeres in series
5. SarcomereZ-disc to Z-disc
6. MyoﬁlamentsSuch as actin, myosin, titin etc.
Action Potential generated at Axon Hillock
1.Gradual depolarization to threshold
2.Rapid rising phase
-Followed by a brief afterhyperpolarization.
Action Propagation / Myelin
1)Action potential propagation is unidirectional.
2)All or none.
3)No decrement in AP magnitude.
4)Conduction velocity depends on axon diameter and the presence/absence of myelin.
5)Myelin is an insulator.
6)Myelin is produced by:
: Schwann Cells
7)Action potential propagation is saltatory
8) At nodes of Ranvier
Activated Nerve Terminal
1) Nerve Impulse
2)Voltage gated Ca+ channel opens Ca+->
3) Neurotransmitter released
Ligand-gated ion channel
~70 vesicles fuse with presynaptic membrane
~6,000 – 10,000 ACh molecules are released/quantal packet (one vesicle)
~250,000 AChRʼs are opened per AP
Excitation-Contraction (EC) coupling
-AP;s travel in T-tubule @ 7cm/s
-Superﬁcial myoﬁbrils contract ﬁrst.
-Conversion of electrochemical energy into mechanical energy.
-AP -- ACh -- AP -- Ca -- Actin/Myosin interaction++