Nervous system connects all your body parts and transmits signals from one part to another. It is a system of cells, tissues and organs that regulates the body’s responses to internal and external stimuli. Nervous system connects all your body parts and transmits signals from one part to another. It is a system of cells, tissues and organs that regulates the body’s responses to internal and external stimuli. The nervous system consists of the brain, spinal cord, and all of the nerves that connect these organs with the rest of the body. This can be divided into two major division: the central and peripheral nervous systems. The central nervous system (CNS) is composed of the brain and spinal cord, while peripheral nervous system (PNS) is the division of the nervous system containing all the nerves that lie outside of the central nervous system (CNS). The central nervous system CNS is responsible for integrating sensory information and responding accordingly. It consists of two main components: 1. The spinal cord serves as a conduit for signals between the brain and the rest of the body. It also controls simple musculoskeletal reflexes without input from the brain. 2. The brain is responsible for integrating most sensory information and coordinating body function, both consciously and unconsciously. Complex functions such as thinking and feeling as well as regulation of homeostasis are attributable to different parts of the brain. ❑The cerebrum, the large, outer part of the brain, controls reading, thinking, learning, speech, emotions and planned muscle movements like walking. It also controls vision, hearing and other senses. ❑ The cerebellum, in the back of the brain, controls balance, coordination and fine muscle control (e.g., walking). It also functions to maintain posture and equilibrium. ❑ Your medulla oblongata is located at the lowest portion of the brainstem. It connects the brain to your spinal cord. It plays an essential role in passing messages between your spinal cord and brain. It's also essential for regulating your cardiovascular, digestive and respiratory systems. ❑ The thalamus processes and integrates all sensory information going to the higher regions of the brain ❑ The hypothalamus is critical for homeostasis, the maintenance of the body's internal environment. It influences nervous control of all internal organs and also serves as the master regulator of endocrine function by its control over the pituitary gland. The PNS has three basic functions: 1. conveying motor commands to all voluntary striated muscles in the body 2. regulating autonomic functions such as blood pressure or sweating. 3. carrying sensory information about the external world and the body to the brain and spinal cord (except visual information: the optic nerves, which convey information from the retina to the brain, are in fact outgrowths from the brain). The peripheral nervous system is so named because it is on the periphery—meaning beyond the brain and spinal The nervous system is involved in receiving information about the environment around us (sensation) and generating responses to that information (motor responses). The nervous system can be divided into regions that are responsible for sensation (sensory functions) and for the response (motor functions). ❑ Nervous system is like a network that relays messages back and forth the brain. ❑ It transmits information through the spinal cord, which extends from the brain down through the back and consists of fine nerves that branch out to every organ and body parts. ❑ When a message reaches the brain from any part of the body, the brain commands the body to respond. ❑ nerve cells handling its information to the next cell, which passes the information to another cells. ❑ finally, the information reaches into its destination and a reaction takes place. For instance, if you hold a rose stem and accidentally prick your fingers, the nerves in your skin release a message of pain to your brain. Your brain, in response to the signal, commands the muscles in your hand to pull away. CRANIAL NERVES its functions are sensory, motor, or both: Sensory cranial nerves help a person to see, smell, and hear. Motor cranial nerves help control muscle movements in the head and neck. SPINAL NERVES considered part of the peripheral nervous system, generally refer to mixed spinal nerves, which carry motor, sensory, and autonomic information between the brain and spinal cord and the rest of the body. The body's sympathetic nervous system is activated by the sudden release of hormones. The sympathetic nervous system then stimulates the adrenal glands, triggering the release of catecholamines (including adrenaline and noradrenaline). The Fight or Flight response is a physiological response triggered when we feel a strong emotion like fear. Fear is the normal emotion to feel in response to a danger or threat. EXAMPLES - the sympathetic nervous system can accelerate heart rate, widen bronchial passages, decrease motility of the large intestine, constrict blood vessels, increase peristalsis in the esophagus, cause pupillary dilation, piloerection (goose bumps) and perspiration (sweating), and raise blood pressure. The parasympathetic nervous system is responsible for the body's rest and digestion response when the body is relaxed, resting, or feeding. It basically undoes the work of sympathetic division after a stressful situation. The parasympathetic nervous system decreases respiration and heart rate and increases digestion. Of all the body systems, the nervous system is the major control system of homeostasis. It provides monitoring, response, and regulation of all systems in the human body and other organisms. It functions from the tiny level of individual cells to affecting the whole body at once. This is the process of homeostasis. Homeostasis refers to the ability of an organism or environment to maintain a state of internal balance and physical wellbeing despite changes or outside factors. Successful homeostasis is vital to the survival of any living thing, and being able to maintain homeostasis even in adverse conditions is one of the most important evolutionary advantages. Example No. 1: Humans' internal body temperature is a great example of homeostasis. When someone is healthy, their body maintains a temperature close to 98.6 degrees Fahrenheit (37 degrees Celsius). When you sweat in summer, that's your body trying to maintain homeostasis by releasing heat. Example No. 2: Glucose is the most basic form of sugar, and the only type the body can use directly. The body must maintain proper glucose levels to ensure a person remains healthy. When glucose levels get too high, the pancreas releases a hormone known as insulin. If blood glucose levels drop too low, the liver converts glycogen in the blood to glucose again, raising the levels.
