Download The Central and Peripheral Nervous Systems: Structure, Function, and Reflexes and more Schemes and Mind Maps Psychology in PDF only on Docsity! I learned in the discussion that the brain and spinal cord make up the central nervous system. The cranial cavity of the skull serves as protection for the brain, and the spinal cord runs from the back of the brain down the middle of the spine before coming to rest in the lower back's lumbar area. The central nerve system, which regulates our thoughts, movements, emotions, and desires, has been extensively researched by anatomists and physiologists yet still harbors many mysteries. In addition, it regulates a variety of bodily functions like breathing, heart rate, hormone secretion, and body temperature. Along with the brain and spinal cord, the retina, optic nerve, olfactory nerves, and olfactory epithelium are sometimes regarded as components of the CNS. This is so that there are no intermediary nerve fibers involved in their connections to brain tissue. In the human body there are 31 pairs of nerves that branched from the spinal cord (spinal nerves) and 12 pairs that emerged from the brain (cranial nerves. These 43 nerve pairs are considered separate from the brain and spinal cord. Therefore, they form the base structure of the peripheral nervous system. The peripheral nervous system is made up of two types of neurons. Sensory neurons also known as afferent neurons and motor neurons also known as efferent neurons. As their name suggest, sensory neurons detect various sensation such as pain and heat. These neurons transmit messages toward the CNS to be interpreted by either the spinal cord or the brain. Motor neurons do the opposite, it transmit messages away from the CNS. These neurons are the stimulate effectors such as the (skin, sense organs, muscles, etc.) to perform a function or reflex. This neurological circuit of information that includes sensory detection, interpretation of sensory input and resulting to motor output is called the reflex arc. A sensory information comes in, it passes through ganglia, which are collections of sensory neuron soma. The ganglia sends this signal into the dorsal section of the spine, where the information is processed. After the CNS processed this information, it then send out the ventral section of the spine via the motor neurons. The motor neurons then carry the processed response towards the effector. The peripheral nervous system also has 2 separate division based on voluntary and involuntary responses or reflexes. Voluntary responses are consciously controlled whereas involuntary responses are unconsciously controlled. Somatic nervous system is PNS division that controls voluntary responses. It is also responsible for relaying sensory and motor information between the outside environment and the CNS. This is due to the fact that most of somatic nerves innervate outer sections of the body such as the skin and skeletal muscles. Hence, any muscle movement or voluntary motor output uses the somatic nervous system. The autonomic nervous system PNS division that handles involuntary movement in the body it generally innervate our internal organ and it controls vital functions that keep us alive. Most importantly, it controls our heart rate, respiration, digestion. All of these and other internal body processes happen without our conscious control due to the autonomic division.
