The brain, nerves and eyes GapFill

A typical reflex arc contains sensory, relay and  messagemotorresponseactive neurones passing a signal from the sensory receptor to the effector. The brain is not involved in a reflex arc, and the coordinator in this case is always the  spinal cordheartliverkidneys.

The brain controls more complex behaviours, with the cerebellum controlling  facial recognitionmemoryspeechfine motor control, and the  brain stemhypothalamuscerebrummedulla oblongata controlling basic functions, such as breathing and body temperature.

The eye is a sensory organ of the central nervous system. The receptor cells of the eye,  haploid and diploid cellspurines and pyrimidineshelices and pleated sheetsrods and cones, are found in the  pupilirisretinacornea, with light passing through the lens. Control of the  hardnessvolumecolourthickness of the lens is how the eye focuses on distant or near objects. People who suffer from  long-sightednesscolour blindnessshort-sightednessquadriplegia have trouble focusing on objects that are far away, but this can usually be corrected easily with  immunosuppressantsglassesinsulin injectionsantihistamines.