PNS contains
cranial, spinal, ganglia, sensory, motor neurons
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| Term | Definition |
|---|---|
| PNS contains | cranial, spinal, ganglia, sensory, motor neurons |
| Sea sponges | Eu, but have no nervous system, |
| Nerve nets - hydras and jellies | Contraction/expansion of body, lack nerves, reflexes only. |
| Sea stars | Centralised nervous system, ring of neurons located in centre, radial nerves to tip, form nets. Eye spot for light |
| Primitive cephalisation | Symmetric animals have ganglia near head to form complex signals |
| Ganglia molluscs, worms, arthropods | Head ganglia are fused, specialised receptors |
| Flatworms | 2 nerve chords running down body |
| Invertebrates | Lack myelin but increase axon diameter |
| Forebrain - optic and olfactory | Telencephalon, diencephalon - cerebrum, thalamus and hypothalamus |
| Midbrain - mesencephalon | |
| Sulci | Cerebral hemisphere forming valleys between gyri |
| Hindbrain - Rhombencephalon | My and mesencephalon - medulla, pons and cerebellum |
| Gyri | Infolded cerebral cortex ridges |
| Motor | Primary and pre in frontal lobe |
| Sensory | Primary somato sensory and association in parietal lobe |
| White matter properties | myelinated, connects grey, larges bundle is corpus callosum |
| Subarachnoid space contains | CSF produced by choroid plexus |
| Afferent cortex input from | Ascending thalamus, stem, fore, Axons between commissural fibres and ipsilateral cortex info |
| Neocortex output | Is excretory from pyramidal, all cortex to thalamus |
| Neocortex axons | Motor and sensory to basal ganglia, project to stem, chord, contralateral and ipsilateral |
| Cerebellum | Proprioceptive, aids cerebral cortex in next move |
| in - Vestibular, chord | out - vestibular, stem |
| in - cerebellar cortex, motor in neocortex | out - muscle spindles, (pre)motor cortexes |
| Afferent fibres leave through | ventral anterior root |
| Spinal nerves all have | posterior dorsal root, containing drg |
| Monosynaptic reflexes | Muscle sensory fibre then alpha motor neuron |
| Polysynaptic reflexes | Produces EPSPs and IPSPs, withdrawal reflex |
| Parasympathetic | craniosacral, rest |
| Sympathetic | thoracolumbar, fight |
| Hillock zone is, | trigger for threshold potential, AIS contains v gated na channels |
| beta IV spectrin | cytoskeletal proteins found in axons and non neuronal cells |
| MAP2 | Neuron specific cytoskeletal protein found in dendrites |
| Motor neuron | Ventral horn of chord, pale staining nucleus, prominent nucleolus. |
| Motor neuron nissl | Prominent bodies, but substance absent in axon as little synthesis |
| Spinal ganglia - DRG and individual | DRG surrounded by connective tissue capsule - continuous with peripheral nerve, surrounded by satellite cells |
| Cerebellar cortex molecular | external, basket and satellite cells |
| Cerebellar cortex purkinje | Single layer of Purkinje cells |
| cerebella cortex granule | internal, granule and golgi cells |
| Purkinje cells | Largest cell in cerebellum, pear shaped bodies and dendritic afferent tree |
| BBB composition | Glial membrane around vessels, endothelial tight junction composition |
| BBB molecular | 500 da Max, lipid and gas soluble, integrity reliant on astrocyte feet |
| Microglia | Phagocytose debris, dormant, cytokines released to help and hinder recovery |
| Oligodendrocytes | Late development, one will myelinate many axons, MS and leukodystrophies damage this |
| Unmye PNS | Schwann envelope unmyelinated axons - these have continuous conduction, pain temp and itch |
| Unmye CNS | Not associated with glia |
| Sarcolemma | Muscle cell membrane |
| Sarco retic | Stores calcium |
| Ligand ion channels, v gated na | at muscle endplate, propagate action potential |
| isometric | load equals force |
| concentric | load is less than force, shortens |
| Eccentric | load is more, lengthens |
| Type 1 - Slow oxidative, 2x is opposite | Slow twitch, high globin, non fatigued, weaker |
| Type 2A - fast oxidative glycolytic | Intermediate |
| Motor unit | one alpha motor and muscle fibres, one alpha will innervate many fibres |
| Alpha motor neurons | Innervate muscle, soma in ventral horn of spinal chord, arranged topographically according to muscles |
| Temporal summation | rapid stimulation summed, for a smooth contraction |
| Spatial summation | More activation means more force, hand muscles |
| Gamma motor neurons | Innervate intrafusal fibres to control spindle sensitivity, required when muscle shortend |
| IA afferents | rate of stretch - bag fibres |
| IL fibres | measure length - chain fibres |
| Golgi tendon organ | Force sensitive, IB afferents, protective reflex contribution |
| Myotatic reflex | muscle stretch, IA to alpha. inhibition of antagonists due to interneurons |
| Clasp knife reflex | tension activates IB, inhibitory interneurons, relaxation. free nerve endings may contribute |
| Crossed extender reflex | pain via a-delta fibres in DRG, excitatory and inhibitory interneuron. Leg flexes, other extends |
| Temporal lobe | audio and association |