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).
Hearing. 1  In the cochlea, both the bony labyrinth and the cochlear duct are coiled in a shape resembling that of a snail shell. Resting along the basilar membrane, which forms the base of the cochlear duct, is an arrangement of sensory cells and supporting cells known as the organ of Corti.