| A | B |
|---|
| neurons | nerve cells |
| dendrites | fibers which bring messages to the cell body |
| axon | carries messages away from the cell body |
| plates | axon branches into finer end branches |
| How do messages travel through a neuron? | messages travel from the dendrites to the cell body then along the axon to the end plate |
| Do neurons touch? | no |
| synapse | a space between neurons that act like a one way valve keeping messages from jamming the main switchboard |
| myelin sheath | a white fatty covering that insulates the neuron and keeps the message from shorting on to a wrong wire |
| white matter | neurons which have the myelin sheath |
| gray matter | neurons that don't have a myelin sheath |
| neurilemma | a tube like structure that encloses a axon and makes it possible for a cell body to grow a new one |
| sensory neurons | carry messages from the sense organs such as the skin eyes ears nose and tongue to the brain and spinal cord |
| motor neurons | carry messages from the brain and spinal cord to a muscle causing movement or a gland causing secretion |
| association neurons | found within the brain and spinal cord they connect the sensory neurons to the motor neurons |
| reflex | turn back |
| reflex arc | the impulse is turned back to a location where it started |
| Why are reflexes important? | they are protective mechanisms blinking, sneezing coughing pulling away |
| central nervous system | brain and spinal cord |
| principal areas of the brain | cerebrum, cerebellum medulla oblongata |
| What is the function of the cerebrum? | forms the top of the brain that receives sensory messages, controls muscles, and allows a person to think |
| cerebellum | coordinating the muscles of the body |
| medulla oblongata | lower part of the brain connects the spinal cord and regulates respiration, heart beat, and digestion |
| How is the brain and spinal cord protected? | in hard bones the cranium and vertebrae |
| meniges | three tissues tha further protect the brain and spinal cord |
| cerebrospinal fluid | further protects the brain and spinal cord |
| fissure | divides the crebrum |
| hemispheres | two halves of the brain |
| cortex | surface area that serves as the control board each area has a particular job |
| convolutions | cortex is folded into ridges which increases the surface area |
| motor area | controls muscles |
| How do the motor neurons connect in the brain? | connect to the opposite side of the body |
| Where are nerve messages regarding touch found? | behind the motor area |
| Where is sight found? | in the rear area |
| What do the lower areas of the cerebrum contain? | centers of speech, hearing , taste, and smell |
| consciousness | interpretation and awareness of all sensations |
| cerebral medulla | many connections of nerve cells made in this second layer of the cerebrum |
| cerebellum | located below and behind the cerebrum, that controls balance and coordination |
| What kind of matter are found in the cerebellum? | gray and white matter |
| medulla oblongata | lowest part of the brain that the spinal cord is attached to |
| What does the white matter serve in the medulla? | a pathway for nerve messages from higher parts of the brain |
| What does the gray matter serve in the medulla? | as a switchboard for sensory messages coming in and going out |
| what do cells in the medulla's gray matter control? | rate of breathing, heartbeat, digestion |
| spinal cord | a long bundle of nerves found within the vertebral column |
| what is attached to the spinal cord? | 31 pairs of nerves carrying messages to and from the spinal cord |
| peripheral nervous system | connects the central nervous system to all of the other parts of the body 43 pairs of large nerves |
| cranial nerves | 12 pairs of peripheral nerves which connect directly to the brain- sight, smell, taste balance |
| vagus nerve | longest cranial nerve that supplies a nerve connection to your organs heart lungs stomach intestines gall bladder |
| spinal nerves | 31 pairs of pheripheral nerves that connect the spinal cord to most external areas of the body |
| autonomic nervous system | controls internal activities such as digestion, respiration, circulation |
| parasympathetic divsion | restrict or slow down activities consticting the pupil of the eye, slowing the heart beat, slow rate of breathing |
| sympathetic division | is an accelerator that can dilate the pupil, speed up the heart beat and breathing |
| optic nerve | sight |
| olfactory nerve | smell |
| statoacoustic nerve | xxxxx |
