Chapter 9 Nervous System
Nervous System Function: The nervous system is composed of neurons and neuroglia. _____sensory_______ _______receptors______ at the ends of peripheral nerves gather information and convert it into nerve impulses. When sensory impulses are integrated in the brain as _______sensations_______, this is the integrative function of the nervous system. Conscious or subconscious decisions follow, leading to motor functions via ______effectors________. |
The Central Nervous System is made up of the ____brain_________ and ______spinal cord______ ______________. |
The Peripheral Nervous System is made up of the _____spinal_________ ...view middle of the document...
Larger axons in the PNS are enclosed by sheaths of _________________ provided by _______________ cells and are myelinated fibers. How do these cells produce this covering? The outer layer of covering in the peripheral neurons is called______________________. What is its function? Narrow gaps in the myelin sheath are called _________ of _______________. |
Neuron Types |
By Structure Describe the three types of neurons as classified by structure. How do they differ? |
By function: ________________neurons (afferent neurons) conduct impulses from peripheral _______________________ to the CNS and are usually what type? ( although some are bipolar neurons.) _____________________ are multipolar neurons lying within the CNS that form links between other neurons. ____________________neurons are multipolar neurons that conduct impulses from the CNS to effectors. |
Cell Membrane Potential: A cell membrane is usually polarized, with an excess of _____________ charges on the inside of the membrane; polarization is important to the conduction of nerve impulses. The distribution of ions is determined by the membrane ______________ _____________ that are selective for certain ions.________________ ions pass through the membrane more readily than do _______________ ions, making the former a major contributor to membrane polarization. |
Resting Potential = Polarized: Due to active transport, the cell maintains a greater concentration of ___________________ions outside and a greater concentration of _______________________ ions inside the membrane. The inside of the membrane has excess ________________ charges, while the outside has more ___________ charges. This separation of charge, or potential difference, is called the resting potential. Sodium/potassium pump: What is its role? Why don’t the sodium and potassium move during the resting potential? |
Neuron Physiology: What is a threshold stimulus doing to the membrane? How does all or none relate to nerve impulse transmission? |
Saltatory Conduction: _____________________ fibers conduct impulses over their entire membrane surface. __________________ fibers conduct impulses from node of Ranvier to node of Ranvier, a phenomenon called ____________________ conduction. This conduction is many times faster . |
Synapse: The junction between two communicating neurons is called a __________________; there exists a _________________________________ between them across which the impulse must be conveyed. Synaptic Transmission it the process by which the impulse in the presynaptic neuron is transmitted across the synaptic cleft to the postsynaptic neuron. When an impulse reaches the knob-like synaptic...