The parasympathetic nervous system does the opposite and returns the body to normal. Sensory neurons are unipolar in shape and there are two types depending on the origin of the sensory neurons. Somatic sensory neurons are located in skeletal muscles and joints of the skin and provide information to the CNS. It is made up of nerves connected to the skin, sensory organs and skeletal muscles. A sensory neuron, photoreceptors in the eye, detects light. The neuronal impulses are then transmitted through the axons of sensory neurons to the brain, where the brain then interprets the meaning of this input. The PNS plays a role in regulating blood pressure, thirst and body temperature. Thermoreceptors in the skin help the body detect temperature. Motor neurons are completely different from sensory neurons because they receive a signal from the central nervous system and tell responsive tissues what to do. Although most often associated with controlling muscle movement, they also signal glandular tissues and control the secretion of various substances like gastric juices and saliva. Visceral sensory neurons provide information to the CNS but not at a conscious level. Some internal organs that need to be regulated, but not at a conscious level, are the gallbladder, liver, kidneys and