Condition characterized by depression.mood changes that occur and go away at the same time, year after year; excessive melatonin levels have been implicated.
Scrotum
A pouch that lies posterior to the penis and anterior to the anus in which the testis are located.
Scoliosis
An abnormal lateral curvature of the spine.
Schwann Cells
Neuroglial cells responsible for myelinating nerves in the PNS; neurilemma cells.
Satellite Cell
Neuroglial cell that surrounds collections of neuronal cell bodies (ganglions) lying outside the CNS; denotes myoblasts seen as individual cells between the muscle fibers.
Sarcomere
The width between two Z lines in a myofibril; the functional unit of the muscle.
Sarcoplasmic Reticulum (SR)
Endoplasmic reticulum found in the muscle fiber.
Sarcoplasm
The cytoplasm of a muscle fiber.