NS2021
Across
- 5. terminal refers to the axon endings that are somewhat enlarged and often club- or button-shaped. Axon terminals are that part of a nerve cell that make synaptic connections with another nerve cell or with an effector cell
- 6. body the nucleus-containing central part of a neuron exclusive of its axons and dendrites that is the major structural element of the gray matter of the brain and spinal cord, the ganglia, and the retina — see neuron illustration.
- 8. cells a type of glial cells of the peripheral nervous system that help form the myelin sheath around the nerve fibers. Myelin sheath of the neuron
- 11. bodies known as Nissl substance and Nissl material, is a large granular body found in neurons. These granules are of rough endoplasmic reticulum (RER) with rosettes of free ribosomes, and are the site of protein synthesis.
- 13. presynaptic receptor located on a neuron's axon, soma, or dendrites that regulate the neuron's release of neurotransmitter
- 14. membrane a specialized area of membrane of the axon terminal that faces the plasma membrane of the neuron or muscle fiber with which the axon terminal establishes a synaptic junction.
- 16. dense group of nerve-cell bodies present in most animals above the level of cnidarians.In vertebrates the ganglion is a cluster of neural bodies outside the central nervous system.
- 17. a detectable change in the physical or chemical structure of an organism's internal or external environment
- 20. a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.
- 22. the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell
- 23. sheath forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells.
- 24. the part of the nervous system that controls and regulates the internal organs without any conscious recognition or effort by the organism. The autonomic nervous system comprises two antagonistic sets of nerves, the sympathetic and parasympathetic nervous systems.
- 25. peripheral nervous system is made up of all the
- 26. system consists of the brain and spinal cord. The brain plays a central role in the control of most bodily functions, including awareness, movements, sensations, thoughts, speech, and memory.
Down
- 1. 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.
- 2. units of the brain and nervous system, the cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between
- 3. surrounds a nerve cell that is responsible for providing mechanical and physical support, supplying nutrients and oxygen to the neuron, providing electrical insulation between neurons, and maintaining homeostasis
- 4. It consists of neurons that are associated with skeletal or striated muscle fibers and influence voluntary movements of the body.
- 7. a sensory receptor which receives stimuli from within the body, especially one that responds to position and movement.
- 9. neuron sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain, while efferent neurons are motor neurons that carry neural impulses away from the central nervous system and towards muscles to cause movement.
- 10. carries nerve impulses away from the cell body. A neuron typically has one axon that connects it with other neurons or with muscle or gland cells. Some axons may be quite long, reaching, for example, from the spinal cord down to a toe.
- 12. a whitish fiber or bundle of fibers that transmits impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs.
- 15. membrane is the membrane that receives a signal (binds neurotransmitter) from the presynaptic cell and responds via repolarization or hyperpolarization
- 18. generally can refer to any neuron that acts as an intermediary in passing signals between two other neurons. Interneurons do not have motor or sensory functions; they just act to pass on information.
- 19. that exist outside the brain and spinal cord. It acts as an intermediary between the central nervous system (CNS) and muscles, skin and sensory organs
- 21. neuron are the nerves responsible for carrying signals away from the central nervous system in order to initiate an action. When sensory input is brought to the brain, it sends signals for a motor response to your muscles and glands via the efferent neurons
- 27. occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate the action potential. Nerve conduction in myelinated axons is referred to as saltatory conduction