Across
- 2. A rapid, short-lasting change in the electrical potential of a neuron's membrane, allowing for signal transmission. (6, 9)
- 5. Many individual neurons grouped or bundled together form this.
- 6. Multiple small extensions of the cell body which sub-divide into smaller dendrites. Carries electrical impulses away from the cell body.
- 7. The junction between two neurons where a signal is transmitted, either chemically or electrically.
- 9. Fatty insulating layer that surrounds the axons of many neurons. Provide electrical insulation and aids in the regeneration of damaged neurons. (6, 6)
- 10. Carries electrical impulses between the sensory neurons and the motor neurons.
- 13. The minimum level of depolarization required to trigger an action potential.
- 15. A single long fibre, type of glial cell. Found in the peripheral nervous system (PNS). They are crucial for maintaining nerve health and function. Specifically, it surrounds and insulates nerve fibres (axons) myelination (6, 4).
- 17. The return of the neuron's membrane potential to its resting state after depolarization.
- 19. Smaller, more numerous, and finer branches that extend from the dendron. Receive incoming nerve impulses from other neurons at synapses. Act as the primary sites for receiving and processing incoming signals. The extensive branching contributes to the large surface area for synaptic connections.
- 20. Carries electrical impulses from the interneurons to the effector (such as a muscle fibre) along a single long axon. (5, 6)
Down
- 1. Surrounds the axon and is made up of lipids and proteins. Associated with the production of proteins and neurotransmitters.
- 3. A chemical messenger that transmits signals across the synapse.
- 4. Carries electrical impulses from the receptors in sense organs to the interneurons. (7, 6)
- 8. A vital protein pump in cell membranes that actively transports sodium ions out of the cell and potassium ions into the cell, using energy from ATP. This process maintains the electrochemical gradient necessary for nerve impulse transmission, muscle contraction, and other cellular functions. (6, 9, 4)
- 11. Gaps between the adjacent Schwann cells where there is no myelin sheath. Allow the conduction of action potential to be faster along a myelinated axon than an unmyelinated one (5, 2, 7).
- 12. The electrical potential difference across the neuron's membrane when it is not transmitting a signal, typically around -70 mV. (7,9)
- 14. A decrease in the negative charge across the neuron's membrane, making it more likely to fire an action potential.
- 16. Where the nucleus, cytoplasm and large amounts of rough endoplasmic reticulum are found. Insulates the axon and speeds up the conduction of the electrical impulses. (4, 4)
- 18. A nerve cell, the basic unit of the nervous system, responsible for transmitting information through electrical and chemical signals.