Nervous system

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Across
  1. 2. one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system.
  2. 4. the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.
  3. 5. a detectable change in the physical or chemical structure of an organism's internal or external environment. The ability of an organism or organ to detect external stimuli, so that an appropriate reaction can be made, is called sensitivity.
  4. 7. also called glial cell or glia, any of several types of cell that function primarily to support neurons.
  5. 9. These are the gaps formed between the myelin sheath where the axons are left uncovered. Because the myelin sheath is largely composed of an insulating fatty substance, the ___ ___ ___ allow the generation of a fast electrical impulse along the axon.
  6. 10. A sensory receptor located in the subcutaneous tissues, and is capable of detecting motion (or movement) and position of the body through a stimulus produced within the body.
  7. 11. critical for neural communication
  8. 14. 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
  9. 15. branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the _____ project.
  10. 17. neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons.
  11. 18. 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.
  12. 22. also called nerve fibre, portion of a nerve cell (neuron) that carries nerve impulses away from the cell body
  13. 23. also called chemical transmitter or chemical messenger, any of a group of chemical agents released by neurons (nerve cells) to stimulate neighbouring neurons or muscle or gland cells, thus allowing impulses to be passed from one cell to the next throughout the nervous system
  14. 24. an insulating layer that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances
  15. 25. also known as nerve cells, send and receive signals from your brain
Down
  1. 1. a membrane receptor protein that is activated by a neurotransmitter. In postsynaptic cells, neurotransmitter receptors receive signals that trigger an electrical signal, by regulating the activity of ion channels.
  2. 3. regulates a variety of body process that takes place without conscious effort.
  3. 6. also called neurilemma cell, any of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons.These cells are equivalent to a type of neuroglia called oligodendrocytes, which occur in the central nervous system.
  4. 8. consists of the brain and spinal cord. It is referred to as “____” because it combines information from the entire body and coordinates activity across the whole organism.
  5. 12. sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain
  6. 13. ___ are ovoid structures containing cell bodies of neurons and glial cells supported by connective tissue.
  7. 16. the membrane that receives a signal (binds neurotransmitter) from the presynaptic cell and responds via depolarisation or hyperpolarisation. The postsynaptic membrane is separated from the presynaptic membrane by the synaptic cleft.
  8. 19. 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.
  9. 20. sites of contact between nerve cells
  10. 21. they are motor neurons that carry neural impulses away from the central nervous system and towards muscles to cause movement.