The parasympathetic nervous system does the opposite and brings the body back to normal. Sensory neurons have a unipolar shape and there are two types based on their origin. Somatic sensory neurons are found in skeletal muscles and skin joints and carry information to the central nervous system. It is made up of nerves that connect to the skin, sensory organs, and skeletal muscles. A sensory neuron, the photoreceptors in the eye, sense light. Neural impulses are then transmitted along the axons of sensory neurons to the brain, where the brain then interprets the meaning of that input. The PNS plays a role in regulating blood pressure, thirst, and body temperature. Thermoreceptors in the skin help the body sense 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 they are often associated with the control of muscle movement, they also signal glandular tissues and control the secretion of various substances such as gastric juices and saliva. Visceral sensory neurons provide information to the central nervous system but not at the conscious level. Some internal organs that need regulation, but not on a conscious level, are the gallbladder, liver, kidneys