| A | B |
|---|
| nervous system | recieves and relays information from the outside environment and responds to internal and external changes |
| neuron | the cells that carries messages throughout the nervous system |
| impulses | electrical signals |
| sensory neurons | carry impulses from the sense organ to the brain and spinal cord |
| motor neurons | carry impulses from the brain and spinal cord to responding muscles or glands |
| interneurons | connects sensory and motor neurons and carries impulses between them |
| cell body | the largest part of neurons which contains the nucleus and cytoplasm |
| dendrites | short, branched extensions which carry impulses towards the cell body |
| axon | long fiber that carries impulses away from the cell body |
| axon terminal | a series of small swellings at the end of the axon |
| myelin sheath | the protective wrapping around the axon |
| nodes of Ranyier | indentations in the myelin sheath |
| stimulus | anything that causes a response |
| resting potential | the neuron has a positive charge on the outside and negative charge on the inside |
| action potential | the neuron has a negative charge on the inside as the stimulus travels |
| threshold | the minimum level of stimulus that is required to activate a neuron |
| synapse | the gap found between neurons |
| neurotransmitter | a substance that is used by one neuron to signal another neuron of an incoming impulse |
| cerebrum | the largest part of the human brain which is responsible for all voluntary activities of the body. It is divided into a right and left hemisphere |
| cerebral cortex | the outer surface which consists of a tissue called gray matter |
| cerebral medulla | the inner surface which consists of tissue called white matter |
| frontal lobe | the front part of the cerebrum |
| parietal lobe | the top part of the cerebrum |
| temporal lobe | the side of the cerebrum |
| occipital lobe | the back part of the cerebrum |
| cerebellum | the second largest part of the brain, located below the occipital lobe of the cerebrum, is responsible for coordinating balance and actions of the muscles so the body moves gracefully and efficiently |
| brainstem | located below the cerebrum, connects the brain to the spinal cord.Is divided into 3 parts |
| medulla oblongata | bottom of the brainstem, controls involuntary functions such as breathing, heart rate, swallowing, blood pressure, and coughting |
| pons | the middle part of the brainstem is composed of white matter and provides a link between the cerebral cortex and cerebellum |
| midbrain | the top and smallest part of the brainstem involved in vision and hearing |
| spinal cord | a tube-like organ that contains neurons, glial cells and blood vessels, serves as a communication link between the brain and the peripheral nervous system and regulates reflexes |
| reflex | the simlpiest response to a stimulus, examples, breathing and sneezing |
| meninges | protective membranes the covers the brain and spinal cord |
| The peripheral nervous system | consists of all cranial and spinal nerves that extend throughout the body and relays messages to the central nervous system |
| cerebrospinal fluid | liquid cushions the brain and spinal cord against shock |
| sensory divisions | transmits impulses from sense organs to the central nervous system |
| motor division | transmits impulses from the central nervous system to responding muscles and glands |
| somatic nervous system | part of PNS which regulates activities under conscious contro;, skeletal muscles |
