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PNS 1
Exam 1: units 0-4
| Question | Answer |
|---|---|
| All neurons whose cell bodies are in the CNA are derived from | the mantle zone of the neural tube |
| All neurons whose cell bodies are in the PNS are derived from | the neural crest |
| CNS multipolar neurons | pyramidal cells (cerebrum), purkinje cells (cerebellum), interneurons, ascending and descending tract, etc |
| PNS mutlipolar neurons | GSE (aka: final comon pathway neurons, alpha motor neurons, LMNs); pre- and postganglionic GVE sympathetic and parasympathetic neurons |
| Pseudounipolar neurons | only in the PNS and are all sensory (GSA, GVA) |
| Biopolar neurons | only in the PNS and are all sensory (olfactory, retinal, spiral ganglion of the cholea) |
| Unipolar neurons | only in the PNS and are all sensory (rods and cones of the retina) |
| Pseudounipolar cell body size | Large = myelinated axons, touch and proprioception; Small = unmyelinated axons, pain and temperature |
| satellite cell (CNS/PNS; position; function) | PNS; dorsal root and spinal ganglia; surround cell bodies, nutritive |
| Schwann cell (CNS/PNS; position; function) | PNS; peripheral ggl and nerves; myelinate a pieve of one axon; associate with all PNS axons; repair and regeneration |
| Oligodendrocytes (CNS/PNS; position; function) | CNS; white and gray matter; myelinate pieves of many axons; not associated with unmyelinated axons |
| Astrocytes (CNS/PNS; position; function) | CNS; physical blood brain barrier; nutrition; glial scarring: neurofibrillar tangles |
| Microglial cells (CNS/PNS; position; function) | CNS; surrounding vasculature; these are the only cells in the CNS derived from the mesoderm: macrophages |
| Ependymal cells (CNS/PNS; position; function) | CNS; surrounding, lining the ventricles and central canal; nurtitive; primary defense; specific cells making up the choroid plexus make CSF |
| Schwann cell's origin and site | Neural crest; PNS |
| Oligodendrocytes origin and site | ependymal layer, neural tube; CNS |
| Ventral root contains what functional components | GSE, sympathetic GVE (preganglion) |
| A-alpha fibers | larger myelinated fibers convey sensory impulses to the spinal cord from elaborate receptors located in the dermis, subcutaneous tissues, muscles, tendons, joint capsules, ligaments, periosteum, and deep fascia. |
| A-delta fibers | smaller myelinated nerve fibers bring sensory information to the cord from less specialized receptors and free nerve endings in the skin, viscera, muscles, and connective tissue of the body. |
| A-beta fibers | larger myelinated fibers convey sensory impulses to the spinal cord from elaborate receptors located in the dermis, subcutaneous tissues, muscles, tendons, joint capsules, ligaments, periosteum, and deep fascia. |
| C-fibers | small, unmyelinated, slow-conduction sensory fibers of the dorsal roots and convey info concerning pain and perhaps other sensations to the cord |
| Synapses En-Passant | Enlargements occurring along axons making synaptic contacts with identical structures of other axons or dendrites. Frequently seen in ANS, especially between nerve fibers innervating smooth musculature |
| Donnan Equilibrium | When a large, charged, noln-ermeable species exists on one side of the membrane, other permeable, charged species will be affected by the non-permeable species. Gradients of passive diffusion will be established. |
| Nernst Equation | |
| Conductance | Opposite of resistance; the ease with which a membrane allows passage of ions from one side to the other (ion channels) |
| Capacitance | |
| Goldman Constant-Field Relationship | magnitude of the membrane potential depends on the relative distribution of Na+, K+, and Cl- across the membrane, as well as on the relative permeability of the membrane to these ions |
| GVE's supply | sweat glands, vascular smooth muscle, erector pili muscles |
| GSE's supply | muscles, glands |
| GSA's supply | skin, muscle, bone, exteroceptors, proprioceptors (special mechanoreceptors) |
| GVA's supply | blood vessels; interoceptors |
| Exteroceptors | external environment: mechanoreceptors (tissue displacement); Thermoreceptors; nociceptors (tissue damage); chemoreceptors |
| Interoceptors | sense events in the viscera |