Fragments of striped (striated) muscle fibers, showing a cleavage in opposite directions, magnified 300 diameters. Striped muscle is nearly always under the control of the will, and is often spoken of as voluntary muscle. Labels: A, longitudinal cleavage; c, fibrillae separated from one another at the broken end of the fiber; c'c", single fibrils more highly magnified, in c; the elementary structures are square, in c" round; B, transverse cleavage; a, b, partially detached disks; b' detached disk, more highly magnified, showing the sarcous elements.

Fragments of Striped (Striated) Muscle Fibers

Fragments of striped (striated) muscle fibers, showing a cleavage in opposite directions, magnified…

Striped, or striated, muscle which quickly contracts causing the alternating black and white lines. It has very delicate fibers (M FL). It is stimulated by nerve fibers (N F), which divide into an endplate (N E) on the contracting surface. N are nuclei, which are a part of elongated cells that fused together to make the muscle. M stands for muscle and N, except for nuclei, stands for nerve.

Striated Muscle

Striped, or striated, muscle which quickly contracts causing the alternating black and white lines.…

A. Portion of a medium sized human muscular fiber. B. Separated bundles of fibrils equally magnified. Labels: a, larger, and b, smaller collections; c, still smaller; d, smallest which could be detached, possibly representing a single series of sarcous element.

Muscular Fiber

A. Portion of a medium sized human muscular fiber. B. Separated bundles of fibrils equally magnified.…

Three muscular fibers running longitudinally, and two bundles of fibers in transverse section, M, from the tongue. The capillaries, C, are injected.

Muscular Fiber

Three muscular fibers running longitudinally, and two bundles of fibers in transverse section, M, from…

Part of a striped muscle fiber of a water beetle prepared with absolute alcohol. Labels: A, sarcolemma; B, Krause's membrane. The sarcolemma shows regular bulgings. Above and below Krause's membrane are seen the transparent "lateral discs". The chief mass of a muscular compartment is occupied by the contractile disc composed of sarcous elements. The substance of the individual sarcous elements has collected more at the extremity than in the center: hence this latter is ore transparent. The optical effect of this is that the contractile disc appears to posses a "median disc" (Disc of Hensen). Several nuclei of muscle corpuscles, C and D, are shown, and in them a minute network.

Striped Muscular Fiber of a Beetle

Part of a striped muscle fiber of a water beetle prepared with absolute alcohol. Labels: A, sarcolemma;…

Muscular fiber torn across; the sarcolemma still connecting the two parts of the fiber.

Torn Muscular Fiber

Muscular fiber torn across; the sarcolemma still connecting the two parts of the fiber.

Transverse section through muscular fibers of human tongue. The muscle corpuscles are indicated by their deeply stained nuclei situated at the inside of the sarcolemma. Each muscle fiber shows "Cohnheim's fields," that is, the sarcous elements in transverse section separated by clear (apparently linear) interstitial substance.

Muscular Fibers of the Human Tongue

Transverse section through muscular fibers of human tongue. The muscle corpuscles are indicated by their…

Diagram showing relation of neurons composing the spinal nerve roots with adjacent nervous structures. Labels: S.E., sensory epithelium connected by a sensory neuron with spinal cord; S.M., striated muscle receiving the axon from a motor-cell in the ventral horn of the gray matter in the cord; Sp. F., spinal fibers, medullated, sensory, and the motor, passing to the sympathetic ganglion where they connect with sympathetic neurons; S.F., S.F., non-medullated fibers from the sympathetic neurons passing to the viscera, the axons going to the plain muscle (P.M.), the dendrites to the sensory endings (S.E.).

Spinal Nerve Roots

Diagram showing relation of neurons composing the spinal nerve roots with adjacent nervous structures.…