Nervous System

" Don't try this at home !! "


" I just stimulated your Sympathetic Nervous System !!!! "

Link to Nervous System Diagram  Look !

Neuron - A nerve cell and the functional unit of the nervous system.

          Dendrite - Receives information and carries the information toward the cell body.

          Cell body - Contains the organelles especially the nucleus.

          Axon - Carries the information away fron the cell body it the next neuron or gland.

Synapse - the junction between 2 neurons or a neuron and a muscle or gland.

Myelin sheath - A fatty coating which provides an electrical insulation to speed the conduction (50 times faster) of a nerve impulse.

          White matter - Myelinated axons.

Grey matter - Cell bodies, dendrites, and unmyelinated axons.

Action Potential - An electrical signal that travels along an axon to the next neuron, muscle, or gland.

*Central Nervous System - CNS - Brain and Spinal Cord

         Cerebrospinal fluid - The fluid found within the CNS. It acts as a shock absorber and is involved in the exchange of nutrients and other materials between the blood and the CNS.

         Simple spinal reflex - simple decisions that can be made by the spinal cord (occur automatically), the brain is not used. Help us sit up, keep us from injury, and maintain muscle tone.

                   Sensory neuron - They carry messages to the spinal cord and brain (CNS).

                   Interneuron - Found within the CNS.

                   Motor neuron - Carry messages away from the CNS and sends a message back to a muscle or gland.

Cerebrum - Largest part of the brain. It is the center of intellect, consciousness, and language.

          Corpus callosum - connects the left (language, reading, and math) and right (emotion of language, art, and creativity) halves of the cerebrum.

          Cerebral cortex - the outer (2-4 mm) gray matter of the cerebrum. It is needed for thought and analysis of information.

                    Occipital lobe - (back) It is involved in visual processing.

                    Temporal lobe - (temples) It is involved in hearing.

                    Frontal lobe - (forehead) It is involved in motor functions.

                    Parietal lobe - (sides at top) is involved in sensory functions like touch, pressure and pain.

Thalamus - a relay center. It can turn the cerebral cortex on or off.

Hypothalamus - links the nervous and endocrine systems and regulates things like thermoregulation, thirst, appetite, sexual behavior, and emotions.

Pituitary gland - Master gland of the body. Produces and stores hormones.

Limbic system - It translates sexual and emotional behavior, anger, hunger, and thirst into actions. The limbic system contains the pleasure and punishment center.

          Endorphins - Are a type of natural pain killer (an opiate)in the brain.

                    Dopamine - A type of neurotransmitter found in the brain associated with feelings of pleasure.

Cerebellum - Function is to control coordination and balance.

Medulla oblongata and Pons - Regulate vital functions like heartbeat, respiration (our breathing center), and blood pressure.

*Peripheral nervous system - PNS - Links the central nervous system (CNS) with sensory receptors, muscles, and glands.

          Sensory - (Carry Information to the brain and spinal cord) & Motor Nerves - (Carry Information away and from the brain and spinal cord)

Somatic nervous system - Motor nerves that go to voluntary muscles (you control)

Autonomic nervous system - Motor nerves that go to things you don't have control over. It goes to smooth muscle (involuntary), heart, organs, and glands.

          Sympathetic nervous system - "fight or flight" system puts the animal into alarm mode. It will increase heart rate, make you more alert, increase muscle strength, and dilates the pupils. It also decreases digestive functions. It is turned on during stress or danger.

          Parasympathetic nervous system - Is for resting activities (digestion). It decreases most activity.

Return to Greg Sievert's GB 100 Syllabus
Last updated on 4 January 2018