Skeletal muscle structure. Different types of muscle tissue. An organism's muscle tissue is composed of muscle cells. Multi-unit smooth muscle cells operate independently and single-unit, or visceral, smooth muscle cells operate together as a unit.Muscle mass can be gained artificially from injections of performance-enhancing drugs and hormones.keletal muscle structure. Different types of muscle tissue. An organism's muscle tissue is composed of muscle cells. Multi-unit smooth muscle cells operate independently and single-unit, or visceral, smooth muscle cells operate together as a unit.
The inner ear contains the sensory organs for hearing and balance. The cochlea is the hearing part of the inner ear. The semicircular canals in the inner ear are part of our balance system. The cochlea is a bony structure shaped like a snail and filled with two fluids (endolymph and perilymph).
The cochlea's afferent innervation pattern. The illustration is shown through the vestibular (Reissner's) membrane, looking down on the spiral organ (of Corti). The principal fiber bundles are 1 and 2; 2a and 3a are internal spiral fibers; 4 are external spiral fibers; 5 and 6 are radial fibers innervating the inner hair cells.