Across
- 7. The neurone after the synapse which contains specific receptor proteins on its membrane, complementary to the neurotransmitter.
- 8. The drop in membrane potential below the resting potential after repolarization due to open potassium ion channels.
- 11. The potential difference across the cell membrane of a neurone at rest which is typically between -60 and -70 millivolts (mV). (7,9)
- 12. The region of the brain that serves as the control centre for the autonomic nervous system. It is responsible for production of hormones, the regulation of the water potential of body fluids and the control of behavioural patterns.
- 13. The physiological reaction of the body in response to a potentially dangerous situation. (5,2,6)
- 14. Unmyelinated sections of nerve cells which allow for the propagation of an action potential due to their many ion channels. (5,2,7)
- 20. The largest region of the brain, consisting of two hemispheres, that receives sensory information from receptors and sends information via the motor neurones to effectors.
- 21. Chemicals that are used for communication between neurones and their target cells.
- 23. A small, hormone-producing gland located at the base of the brain. It is divided into two regions, the anterior pituitary and the posterior pituitary. (9,5)
- 26. A type of neurotransmitter that is used for communication between neurones.
- 27. An excitatory synapse formed between a motor neurone and a muscle fibre that uses the neurotransmitter, acetylcholine. (13,7)
- 28. The region of the brain that controls muscle coordination and non-voluntary movement (e.g. balance, posture).
- 30. The combination of many impulses that can cumulatively stimulate the generation of an action potential in a postsynaptic neurone.
- 31. Pairs of nerves that originate from the CNS and carry nerve impulses into and out of the CNS. It is divided into the sensory nervous system and motor nervous system.
Down
- 1. The setting up of localised circuits between nodes of Ranvier which allows for the rapid propagation of an action potential. (9,10)
- 2. The neurone before the synapse which releases neurotransmitters from synaptic vesicles into the synaptic cleft.
- 3. The principle that describes how any generator potential which reaches or exceeds the threshold potential will produce an action potential of equal magnitude. (3-2-7)
- 4. Specialised structure that detects a specific type of stimulus. Reflex: A rapid, automatic response to a sensory stimulus by the body.
- 5. A branch of the autonomic nervous system that is active under normal, resting conditions. It inhibits effectors, slowing down activity.
- 6. An organ, tissue, or cell that produces a response to a stimulus.
- 9. A branch of the nervous system that carries impulses to the skeletal muscles. It controls voluntary activities.
- 10. A branch of the nervous system that carries nerve impulses to muscles and glands. It controls involuntary activities and has two divisions: the sympathetic nervous system and the parasympathetic nervous system.
- 15. An extension from a nerve cell that carries impulses towards the cell body.
- 16. A neurone that carries nerve impulses from the receptors to the CNS.
- 17. An extension from a nerve cell that carries impulses away from the cell body.
- 18. The brain and spinal cord.
- 19. A neurone located in the spinal cord that links the sensory neurone to the motor neurone.
- 22. A neurone that carries nerve impulses from the CNS to the effectors.
- 23. A type of sensory receptor which detects changes in pressure on the skin. (8,9)
- 24. The rapid influx of sodium ions into the cell which cause it to lose its negative charge and the membrane potential to increase.
- 25. Cells that form the myelin sheath around nerve cells in the peripheral nervous system. (7,5)
- 29. A branch of the autonomic nervous system that is active under stressful conditions. It stimulates effectors, speeding up activity. Synapse: The junction between two nerve cells or a nerve cell and an effector.