The soma or perikaryon or cyton is the bulbous end of a neuron containing the cell nucleus. Nissl body, also known as nissl or tigroid substance, a large granular body found in the cyton or dendrites of neurons is:

Erythrocytes, also known as red blood cells (RBCs), function to transport oxygen in the blood. Mammalian erythrocytes are typically shaped as biconcave disks that are flattened and depressed in the center with a dumbbell shaped cross section and a torus shaped rim on the edge of the disk. Oxygen transport is efficient because the cells have a flattened disc shape to increase surface area allowing rapid diffusion of oxygen, and they contain haemoglobin which absorbs oxygen in the lungs and releases oxygen in the rest of the body.