PHYS30005 Lecture Notes - Lecture 32: Capillary Action, Motor Neuron, Clenbuterol
13 Aug 2020
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Document Summary
Motor unit: the motor neuron and all the muscle fibres under its control. 3 main motor unit types: slow, fr, ff. Grouping of fibres by myosin heavy chain (myhc) composition. 10 myhc species identified in mammalian muscle fibres. Limb muscles: type i slow, iia, iix (iid), and iib. Diagram that tells us why muscles can adapt and modify their properties. If loading on soleus muscle was changed - Fibres as hybrids containing more than one myhc. Fibres exist as either pure (one type of myhc) or as hybrids containin multiple forms: eg. I + iia, i + iia + iix, iia + iix. Myosin heavy chain in single fibres of human muscles. Sr density, capillary density, mitochondria, fiber diameter, contractile and regulatory proteins, fiber composition. Slow fibre in the mouse is not necessarily the same as slow fibre in cat or human. 4 myhc"s in limb muscles of smaller mammals vs. 3 in human.
