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Anatomy
Nervous System
Question | Answer |
---|---|
Axon | Single long fiber that carries impulses away from body. |
Cerebrum | Largest part of brain, thinking, memory is stored, movements are controlled, impulses from senses are interpreted. |
Dura mater | Outer layer that protects the central nervous system. The tough outermost membrane enveloping the brain and spinal cord. |
Neuron | Scientific name for a nerve cell. |
Cerebellum | Responsible for the coordination of muscles and is the center of balance. |
Motor or Efferent Neurons | Send info away from the central nervous system to muscles or glands. |
Dendrites | Receives messages, impulses sends to body. Branched parts of a neuron that receive impulses from other neurons. |
Cyton | Cell body. Contains cytoplasm and the nucleus. |
Arachnoid Layer | Middle layer that protects the central nervous system. A delicate fibrous membrane forming the middle of the three coverings of the central nervous system. It is tenuously attached to the externally adjacent dura mater. |
Hypothalamus | A region of the forebrain below the thalamus that coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, and involved in sleep and emotional activity. |
Reflex Arc | The nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between. |
Mylon Coating (Sheath) | A wrapping of myelin around certain nerve axons, serving as an electrical insulator that speeds nerve impulses to muscles and other effectors. |
Meningnes | The three membranes (the dura mater, arachnoid, and pia mater) that line the skull and vertebral canal and enclose the brain and spinal cord. |
Interneuron | Send info between sensory neurons and motor neurons. Most located in the central nervous system. |
Synapse | A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter. |
Medulla | Center of heart beat, respiration and other involuntary actions |
Spinal Cord | Extension of the brain stem. Bundles of neurons that carry impulses from all parts of the body to the brain and form the brain to all parts of your body. |
Nervous System | The network of nerve cells and fibers that transmits nerve impulses between parts of the body. |
Response | How the body reacts to a stimulus. |
Pia matar | Inner layer that protects the central nervous system. The delicate innermost membrane enveloping the brain and spinal cord. |
Thalamus | Receives messages from sensory receptors; replays into the proper regions of cerebrum. |
Gray Matter | Absence of myelin in masses of neurons accounts for the gray matter of brain cerebral cortex. |
White Matter | Myelinated neurons gives neurons a white appearance. Inner layer of cerebrum. |
Neurotransmitter | A chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure. |
Stimulus | A change in the environment. |
Somatic | You control; controls voluntary actions. |
Autonoic | You don't control; involuntary actions. |
Opiates | Mimics endorphins, used to relieve pain. Act as a depressant, cause drowsiness, restless, nausea. |
Depressants | Decrease heart rate, breathing rate, blood pressure, relax muscles, relieve tension. Enhances release of neurotransmitters that prevent nerve cells from firing. Used to relieve anxiety, irritability, tension. |
Stimulants | Increase heart rate, blood pressure, breathing, release. Increase alertness, relieve fatigue. |
Marijuana | Retards normal brain growth, memory, math and verbal skills, males reduce testosterone, increase estrogen, females disturbs menstrual cycle, DNA damage to eggs. |
Cocaine | Opiate, sudden release of dopamine. Increase heart rate and blood pressure. |