BC: The Peripheral Nervous System | Peripheral Nerves: There are forty-three pairs including twelve pairs of cranial nerves that connect to the brain. Parasympathetic: Division of the autonomic nerve system that tends to slow down activities. Vagus Nerve: Longest cranial nerve. Autonomic Nerve System: Controls internal activities such as digestion, respiration, and circulation. | The peripheral nervous system connects the central nervous system to all of the other parts of the body. The cranial nerves involve sight, smell, taste, balance and other functions. The vagus nerve supplies nerve connection to most of your internal organs such as your heart, lungs, stomach, intestines, and gall bladder. The vagus nerve is an autonomic nerve. There are two divisions in the autonomic nerve system. One called parasympathetic, the other called sympathetic. The parasympathetic control such activities as constricting the pupil of the eye, slowing down the heart beat, and slowing the rate of breathing. The sympathetic division is like an accelerator. It can dilate the pupil, increase the rate of breathing, and speed up the heart. | The end:) | Factors That Affect System Over Time | One factor that affects it is neurological disorders. Which are health conditions of the nervous system. Another is nerve damage. ex. Diabetic Neuropathies. Or Multiple Scleroris. Even drugs and alcohol affect the nervous system. Drugs such as marijuana, hinder the users movement and memory in the brain. Alcohol affects the human nervous system by taking over signals between the brain, nerve endings and spinal cord. When people drink, their bloodstream absorbs the alcohol and nervous system functions slow down dramatically-that's when people feel like the numbness from drinking.
FC: The Nervous System | By: Payton Rund | Easter egg hunt edition. Find all 7 easter eggs!!! :)
1: The Neuron | Neuron: Tiny nerve cell. Dendrites: Nerve fibers which carry messages towards the cell body. Axon: Nerve fiber which carries messages away from the cell body. White Matter: Neurons that contain a myelin sheath. Gray Matter: Neurons that are lacking the myelin sheath. | There are three types of neurons: the Sensory Neuron, the Association Neuron, and the Motor Neuron. Neurons can only carry messages one way. Sensory Neuron: carry messages from the sense organs such as the skin, eyes, ears, nose, and tongue towards the brain and spinal cord. Motor Neuron: Carry messages from the brain and spinal cord to either a muscle, causing movement, or to a gland, causing a secretion Association Neuron: Found within the brain and spinal cord. They serve to connect the sensory neurons to the motor neuron. | As a nerve message travels along the neuron to the end plate, a new message is generated in a new neuron. The message must cross over to the other neuron over a synapse or a space. Synapses act like one-way valves, making sure the messages don't go the wrong way.
2: The Reflex | Reflex: Turn back. Involuntary: How a person doesn't have to learn reflexes, they are just born with them. Reflexes are important since the are mainly protective mechanisms in nature. | As the doctor strikes the leg, a nerve message is carried by a sensory neuron to the spinal cord. Then down the leg to the muscle. When the muscle contracts, the lower leg is jerked upward. Coughing and sneezing protects the air passages, and blinking protects the eye.
3: The Central Nervous System | Central Nervous System: Composed of the brain and spinal cord. Meninges: Three tissues that cover the brain and the spinal cord. Cerebrum: Receives sensory nervous messages. Cerebellum: Responsible for muscular coordination. Medulla Oblongata: Connects downwards to the spinal cord. | The principal areas of the brain include the cerebrum, the cerebellum, and the medulla oblongata. To protect the brain and spinal cord, the are enclosed in hard bones. The cranium of the skull covers the brain and the vertebra enclose the spinal cord. Then the surface of the brain is covered by the three tissues called meninges.
4: The Cerebrum | Hemisphere: Each half of the cerebrum. Cerebral Cortex: The surface layer of the cerebrum. Motor Area: Controls movements of muscles. Fissure: The deep groove which divides the cerebrum. Rear Area of the Cerebrum: Where the sensations of sight are centered. | The cortex serves as the control board of the nervous system. Each small area of the cerebral cortex has a particular job to do. The motor area runs over the brain between the ears, and is about two inches wide. If one side of the cerebrum gets damaged, then the opposite side of your body would also get damaged. The interpretation of all of the senses is called consciousness. Many connections are made by a second layer called the cerebral medulla.
5: The Cerebellum,Medulla, and Spinal Cord | Cerebellum: Controls balance and coordination. Gray Matter: Controls breathing. Vertebral Column: Contains spinal cord. Spinal Cord: Is connected to thirty-one pairs of nerves. Medulla Oblongata: Lowest part of the brain. | Below and behind the cerebellum is the cerebrum. The cerebellum is divided into two hemispheres that are folded. If the cerebellum became damaged, muscular movements will become jerky and unpredictable. The spinal cord is attached to the medulla. The white matter is on the outside. It serves as a path way for nerve messages. The gray matter serves as a switchboard. The spinal cord is a long bundle of nerves found within the vertebral column. Some nerves carry messages to the brain, and other nerves carry messages to muscles and glands of the body.