4451550
Description
Flashcards by James Murdoch, updated more than 1 year ago
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Created by James Murdoch
almost 10 years ago
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| Question | Answer |
| Cells that myelinate the nerve cells in the CNS/PNS? | Oligodendrocyte/Schawnn cells |
| PSNS vs SNS differences? | PSNS longer pre ganglionic neurone PSNS neurotransmitter always ACh |
| What decreases the risk of NTD? | Folic acid |
| Number of layers in the cortex? Neurones break through which plate to reach cortical plate? | 6 Subplate |
| Where do the two dura layers spilt? | When brain fissures at falx cerebra |
| The superficial layer is different to the deep layer how? | Not continuous with the spinal cord |
| What allows the CSF to drain into the sinuses at the Falx cerebri? | Arachnoid Villi |
| Tentorial herniation occurs why? and damages what? | SOL (tumour) causing dura to exert pressure on the brain leading to Brainstem/cerebral and cranial nerve damage |
| Collections of arachnoid villi are called? | Granulations |
| CSF produced by what cells? | Choroid plexus |
| Haemorrhage types and what vessels burst? | Extra dural- meningeal arteries Sub dural-cerebral veins Subarachnoid-Cerebral artery |
| Four differences in CSF and blood? | Low glucose and potassium Protein and cholesterol |
| Describe CSF circulation? | Lateral to 3rd to 4th into subarachnoid space |
| What happens when CSF is continuosly produced? | Hydrocephalus |
| What areas lack the BBB? | Areas around 3th and 4th ventricle |
| Dicenphalon is? | Thalamus/hypothalamus |
| Hypothalamus connected to, functions? | Connected to pituitary gland, maintains drinking eating and circadian rhythms |
| Functions of the amygdala and hippocampus? | Social behaviour and emotion memory |
| Functions of temporal/occipital/parietal | Auditory/visual and sensory and motor functions |
| Explain the loop involving the basal ganglia and SMA | Basal ganglia to the ventral nucleus which is in the thalamus, this directs info to the SMA that distributes it amongst the cortex then back to basal ganglia |
| Lentiform nucleus/striatum are composed of? LN is lateral or medial to the internal capsule | Putamen/GP Putamen and caudate nucleus Lateral, GP most medial then putamen |
| Connections from the BG to the thalamus are? | Internal segments of the GP and substantia nigra (pars reticulate) |
| Dopamine containing neurones are? | pars compacta |
| Direct and indirect pathways function? Describe each pathway briefly? | Direct activate movement Indirect inhibit movement GABA inhibition of IGP so no longer inhibits thalamus, Glutamate stimulation of IGP so increases tonic inhibition of thalamus |
| Parkinsons disease is caused by degeneration in what part of the brain? | Substantia nigra |
| Huntingtons disease | Lost of striatal neurones and then lost of cortical neurones |
| Ballism is caused by? | Damage to subthalamic nuclei, and it excites the IGP that inhibits movement. |
| The vertebral arteries branch off where? | Subclavian |
| Describe what part of the brain each branch of COW supplies? | ACA-Parietal and frontal MCA-temporal PCA-occipital |
| Lower limb,Upper limb and face motor and sensory arterial supply? | Anterior supplies lower limb and middle supplies upper limb |
| Describe a watershed infarct? | When perfusion pressure is low can occur where blood supply overlaps? |
| Commonest site for an ischaemic stroke and why? | Middle cerebral artery, connected to ICA, so emboli elsewhere in the body can reach the MCA |
| CBF=, how much of the CO does the brain use? | CPP/CVR 15% CPP=MAP-ICP |
| Range of brain auto regulation? | 50-170 |
| CBF maintained by what 3 things? | Neural/metabolic/myogenic Neuronal control is weak |
| PSNS/SNS control arises from where? | Facial and superior cervical ganglion |
| Metabolic control? | Decreasing pH and increases CO2 pressure causes VD Increases in K+ causes VD |
| Reduction in O2 supply triggers production of what chemical | Adenosine within 5 secs |
| Myogenic control does what to vessels | Constricts them |
| Marker used for fMRI | gadolinium |
| Final type of brain imaging | PET |
| Three components of the skull | Brain tissue/blood/csf |
| Average ICP | 20mmHg True is between 5-13mmHg |
| CPP/mean BP/ ICP equation | CPP=MAP-ICP |
| Cardiac arrests causes what at watershed zones? | Hypoperfusion causes ischeamic |
| Four causes for raised ICP? | Edema/hydrocephalus/bleeding/SOL |
| S&S of raised ICP? | Headache papillodema vomiting Pupil changes/hemiparesis |
| Types of intracranial herniation? | Subfalcine/transtentorial/foramen magnum |
| Effects of a transtentorial herniation? | Compressed PCA/Crn 3 |
| Berry anerysm occurs which intracranial space? | Sub arachnoid |
| Secondary tumours of the brain come from where? | lung/breast/skin/renal + colon |
| Primary tumours relatively affect which demographic the most? | children Medulloblastoma Pilocytic astrocytoma |
| Two types of hydrocephalus? | Non-communicating=blockage Communicating=thickening of arachnoid villi |
| Are neurones terminally differentiated? | Yes |
| Human brain consumes what % for each of the following: CO/02/Glucose | 15/20/25 percent |
| The nernst Equation tells us what? | The equilibrium potential for to be no net movement of that particular ion |
| Goldmanns equation uses what three variable? | Conc gradient Voltage gradient Membrane permeability |
| If the RMP becomes closer to Nernst potential what has happened to the permability? | It has increased for the ion, Na+ it depolarises |
| Where are the action potential generated? | Axon hillock |
| For saltatory conduction which is more important for the speed of the impulse myelination or diameter? | Diameter |
| Astrocytes have what functions? | Metabolising neurotransmitters/bridging between blood vessels and neurones/regulating ionic conc |
| The WBC of the brain are called? | Microglia |
| What lines the ventricles? | Ependymal cells |
| Number of cells it myelinates Schawnn and oligodendrocytes? | 1/10 |
| Microplagia form amyloid plaques in what disease? | Alzheimers |
| Summation allows? | Single EPSP not adequate to reach threshold potential |
| How do neurones pass info? | By rate of coding, this controlled by the synapse |
| Sensory discrimination is sharpen by? | Lateral inhibition |
| EEGS release frequencies what does delta/theta/alpha/beta indicate | sleep/memory/restfullness/active concentration |
| Dopamine depletion occurs where? | striatum |
| Levodopa is given with what other drug? Commonest side effect with levo dopa? | Carbonic anhydrase inhibitor dyskinesias |
| +/- of direct dopamine agonists? | bypasses nigrostriatal neurons activation of peripheral dopamine receptors |
| What cant you consume when on a MAO-B inhibitor such as selegiline? | Tyramine/tricylics anti depressants |
| Dopamine depletion leads to what? | cholinergic overactivity give you dry mouth |
| Deep brain stimulation implant is located where? | subthalamic nucleus/GP/thalamus |
| Gene therapy use what? | Neurotrophins-BDNF |
| Huntington disease is causes by increases numbers of what codon? | Glutamine |
| CAG repeat length determines what? | Onset however rate of progression does not! |
| Potential therapies for Hungtindons? | coenzyme Q10/creatine(2care crest-e) |
| Somatosensory conveys all sensory to the CNS apart from? Methods of obtaining info? | Special senses Extero/Intero/Proprio |
| Where do sensory afferent neurones decussate? What cell type? Synapse where? | In the spinal cord Pseudouni-polar Dorsal horn |
| Sensory ganglia are found where? In cranial nerves? | Dorsal root ganglion trigeminal ganglion |
| Peripheral neuropathy presents in what fashion? | Glove and stocking |
| The stimulus strength is indicated by what? | The rate of AP |
| 5 variables for sensory afferent neurones? | Modality/Threshold/Adaptation Conduction velocity/Receptive field |
| What is an adequate stimulus? | Type of energy that the receptors respond to most effectively |
| Low versus high threshold types? | Low-touch/warm/cool High-Nociceptors |
| Slowly/rapidly adapting fibres? | Stretch receptors are SA RA react to movement/acceleration |
| Are A fibres myelinated? C fibres run in what? | Yes Run in remak bundles |
| Receptive field in primary afferent neurones? | site of projection of the peripheral terminal |
| Which fibres have the slowest and quickest conduction velocity? | Aa fastest C slowest |
| Non-nociceptive cutaneous fibre class? | AB |
| Pacinian corpuscle? | Fibroblasts/modified schwann cell RA/deep |
| Meissners corpuscle? What plays the role of these in hairy skin | Mechanoreceptor and low frequency vibration Only in glabrous (no hair) RA/superficial G cells |
| Merkel cells? | Special senses/touch cells SA/superficial |
| Ruffini? | Tissue stretch sensor Deep/slowly adapting |
| LTM stand for and what fibre type? | Low threshold mechanoreceptors c fibre |
| Two types of muscle afferents, general characteristics? | 1a dynamic adaptation/change in stretch II static adaptation/tonic stretch |
| Type 1&2 tendon and joint receptors | Ruffini and Pacinian corpsule |
| 4 types of processing in the ascending pathway? | Convergence/divergence/lateral inhibition/centrifugal control of neuronal facilitation(accurate transmission of sense/awareness of part of body) |
| Lateral inhibition releases what NT? | GABA |
| Define nociception? | Detection of stimulus that is potentially harmful |
| Pain is transmitted in what fibres, where to the cell bodies of these sit? | C and Adelta Dorsal root ganglion/nodose/cranial |
| Cutaneous nociceptors have? Sharp pricking pain versus slow burning pain? | Free unmyelinated ending Adelta is sharp pain C is slow dull pain |
| TRPV-1 is found where? Describe its action | Located in C-fibre terminals Ion channel activated by capsaicin, cation so leads to depolarisation |
| Why does a burn continue to hurt at room temp? | TRPV-1 Threshold to heat decreased by prostaglandins/bradykinin/histamine which are released during inflammation. So more are active at lower temperatures |
| Nociceptors release what substances? | Glutamate-main excitatory CGRP/Substance P-Modulatory role slow EPSP |
| Central sensitisation Where does windup occur? | WINDUP constant stimulation of C-fibres that lead to more evoked AP's in WDR neurones Lamina V |
| Give a few differences between high and low threshold primary afferents? | Nociceptives=smaller/higher threshold/large peptide content (substance P CGRP) Slowly adapting |
| Gate control theory stimulates what fibre to counter act pain? | AB |
| Spinothalamic tract where does it decussate? | Immediately |
| Cortical areas active in pain? | Primary sensory cortex/association cortex Anterior cingulate cortex |
| Interoceptive activates what? | Insular cortex, also where we imagine pain and the intensity of pain |
| PAG/Amydala/hypothalamus role in pain? | FIght/flight fear/anger/anxiety nausea and cvs affects |
| Descending control of nociception? | via PAG Uses neurotransmitters like serotonin/na/opioid peptides |
| Major sites of analgesic opioid actions? | Presynaptic terminal depresses glutamate release Post synaptic, inhibits spinothalamic activity K+ channel activation PAG |
| Neuropathic pain? De afferentation pain? | Stimulus origanates somewhere along pain pathways phanton limb |
| Referred pain? | Pain is perceived at a location other than the site of painful stimulus |
| Define Hyperalagesia/allodynia? | Increased pain from noxious stimulus pain from non-noxious stimulus(sunburn) |
| LA two effect on NA Channels? | Block Na channels and prolong Na channel inactivation |
| Small or large fibres blocked more readily? | Small fibres, pain is transmitted via Ad+C fibres |
| Two drugs that exhibit LA properties at high concentrations? | Propanolol/morphine |
| Two pathways that LA use? | Hydrophobic/hydrophilic Hydrophobic diffuses from cell membrane directly into the receptor. Hydrophilic diffuses across the membrane into the cytosol and then binds to the receptor |
| What LA is only used experimentally and give an example of LA that uses the hydrophobic pathway? | QX-314 (100% ionised) Benzocaine |
| Explain use dependance? | The more the nerve fibres fire the greater the effect of the LA |
| Metabolism mechanisms of LA/Does LA VC or VD? | Ester-Plasma Amide-Liver potent VD |
| Clinical uses of LA (6)? | Surface/infiltration/IV/Nerve block/spinal/epidural |
| Side effects of LA? | Respiratory depression/decreased heart contractility Hypersensitivity Toxic metabolite-prilocaine causes methaemoglobinaemia |
| Opioid vs Opiate? | Opioid acts on opioid receptors Drugs derived from juice of opiates |
| Where do C fibres terminate? What tract to nociceptors use? | Dorsal horn Spinothalamic tract |
| What inhibits pain transmission in substantia gelatinosa? Causes local release of what? System is activated by what drug? | PAG Dynorphin Opiates |
| List the four opioid, what are three inhibited by? | MOP/KOP/DOP/NOP Naloxone |
| Problem with giving morphine orally? When do u give morphine orally? | FPE poor absorption Oromorph for cancer patients |
| Side effects of morphine? | Miosis(pupil constriction) Respiratory depression/alveolar hypoventilation anti-tussive |
| With what and where is morphine metabolised, where is it excreted? | glucoronic acid, liver. In the kidney |
| Most potent, given to help with opioid addiction,prodrug and life saving antagonist? | Fentanyl/methadone/codeine/naloxone (much shorter half-life than morphine) |
| Two types of anaesthetics? | inhalation and intravenous FLURANE=inhalation |
| MAC stands for? | Minimum alveolar concentration that produces surgical anaesthia in 50% of patients |
| Entonox? Side effects? | N20 mixed with O2 (50%) Inactivates B12 neuropathy Low solubility in blood so blood becomes easily saturated |
| First halogenated ethers in Uk? Potential side effects of modern fluranes? | Halothane no longer in use as causes liver toxicity Malignant hyperthermia |
| malignant Hyperthermia is caused by a problem with what receptor? | Abnormal ryanodine receptor massive increase in ca2+ in SR Give dantrolene |
| What do you give to stop malignant hyperthermia? | Dantrolene |
| What drug can you not give to people with a peanut/soya allergy? | Propofol |
| Thiopental suppresses what production? Used to treat what? | Cortisol Status epilepticus |
| What do you give to people with Status asthmaticus? | ketamine |
| Side effects of Ketamine | Ulcerative cystitis |
| Two types of NMJ blockers? | Depolarising-Sux Binds to receptor/4min t1/2/malignant hyperthermia/pseudochol Non-depolarising-curium/curonium Antagonists/40min t1/2/neostigmine/tachycardia and hypotension |
| Which cranial nerves do not synapse in the brainstem? | Olfactory/Optic |
| Edinger Westschal nuclei for which cranial nerve? | Oculomotor |
| Functions of the cranial nerves? | SSA/SVA/SVE GSA/GVA/GSE/GVE |
| Optic and Vestibulocochlear | Only associated with SSA |
| Three symptoms of damage to the CR8 | Ataxia,loss of balance and nystagmus |
| The olfactory nerve is unique cause? | Only nerve that is only associated with SVA |
| GSE motor nerves? | Hypoglossal/oculomotor/Trochlear/abducens/accesory |
| Ptosis/lateral strabismus is damage to what nerve? | oculomotor |
| Hypoglossal nerve palsy deviates to side? | Same side as lesion |
| 4 nerves that are involved in both sensory and motor? For trigeminal which lesion causes damage to jaw? | Trigeminal/facial/Glossopharnygeal/Vagus LML |
| Special about the forehead muscles? What causes bells palsy? | Bi-lateral innervation LML damage of facial nerve |
| What part of the cranial innervates the SCM/traps and what does the other part do? | Spinal Roots to the pharynx/larynx |
| Bilateral corticonuclear connections present in all cranial nuclei except? | Lower part of the face Hypoglossal nucleus that supplies the genioglossus muscle |
| Motor neuron location in ventral horns of ventral and dorsal? | Flexors-Dorsal Extensor-Ventral |
| 3 sources of input of the motor a neuron? Difference between A & Y fibres Motor unit? Muscle length determined by what? | Inter-neurones/Upper motor neurones/sensory input from muscles A innervates skeletal muscle fibres, Y innervate intrafusal muscle fibres/adjust sensitivity of muscle spindles Muscle fibres and respective a neurone Muscle spindles |
| Monosynaptic reflex maintains what? Exaggerated reflex indicates? Gamma motor neurones do what to the spindles? | Muscle tone Upper motor lesion Cause contraction when the muscle contracts |
| Golgi tendon does what? Helps protect what? | Opposite monosynaptic to prevent tendon damage |
| Flexor reflex receives stimulus from what types of fibres? Maintenance of balance is done how? If your left arm flexes your right arm will? | Nociceptives (ad+C) Crossed extensor reflex, maintained by the central pattern generator (excitatory and inhibitory interneurones) Extend |
| Convergence is what, causes three things? | Multiple nerves into one nerve Summation/Facilitation/Occlusion |
| Basal nuclei function? | Initiation and control of movements |
| Rubrospinal synapse? | Red nucleus |
| Describe the pathway that the basal ganglia are involved | Motor cortes/PFC to Basal ganglia to ventral tegmental nuclei to SMA then down spinal tracts |
| Striatum is,separated by what? Lentiform nucleus? Output regions of basal nuclei? What is NA involved in and what carries dopamine from substantia nigra? | Putamen/caudate internal capsule Globus pallidus/Putamen Internal segments of GP and pars reticula of SN Reward, Pars compacta |
| Which pathway allows movement? | Direct |
| Describe basal ganglia pathway? | Removes tonic inhibition of IGP on thalamus by the striatum inhibiting it |
| Indirect pathway? | Inhibition of the thalamus above normal level, Inhibition of EGP tonic inhibition of Subthalamic nucleus that excites IGP |
| Parkinsons disease causes and symptoms? | Loss of pars compact in substantia nigra, trouble initiating movements, bradykinesia |
| Hungtingtons disease? | Loss of striatal neurones thus loss of cortical neurones dementia/movement problems |
| Damage to subthalamic nucleus causes? | Ballism cause this excites the IGP so if you remove this you have no control of movements |
| Commonest causes of ballism? | Stroke |
| Motor areas can produce movements how? | Lowest stimulus intensity |
| Primary motor cortex neurones fire before or at the same time as movement? | before |
| Describe the location of the SMA? Pre-SMA differs from SMA proper how? | Directly anterior to Primary motor cortex Connected to PFC not strongly connected to other motor areas |
| Which pathway lateral or medial controls proximal and distal muscles? | Lateral thus medial control axial muscles |
| Lateral pathways/medial pathways? | lateral corticospinal/rubrospinal Vestibulospinal/reticulospinal/tectospinal/ corticospinal |
| Percentage of corticospinal neurones that decussate? and where? Lateral innervates what? | 85% medullary pyramids Limbs |
| Corticobulbar fibres involved in cranial nerve functions, what nuclei do not receive bilateral innervation from cortex? | Facial muscle below eye and hypoglossal |
| When does rubrospinal tract decussate?What does it innervate? | Immediately Upper limb |
| Motor that innervate flexors are dorsal or anterior to those that innervate extensors? | Dorsal |
| Head orientation is received from tract? Innervation to muscles? | Vestibulospinal tract bilateral innervation |
| Where does tectospinal tract originate? Function? | Superior colliculi Control head position |
| Which tract is involved with muscle tone? Ipislateral or contralateral? | Reticulospinal tract ipislateral |
| Consequences of upper motor injury? | Increased muscle tone/hyperactivity Barbinski sign/weakness in digits |
| Barbinski sign is normal in infants because? | Of lack of myelination of corticospinal tract |
| Most prominent sign of impairment to the corticospinal tract? | Weakness in digits |
| In a LML what affect on spasicity and reflexes? | Decreases muscle tone and reflexes |
| Difference between decorticate and decerebrate postures? | Decorticate-Cerebrum from brainstem Arms abducted and flexed (on chest) Decerebrate- Separates upper and lower brainstem Arms extended/wrist pronated arms are by the side |
| Two things you get with LML that you don't get with UML? | Fasciluations/atrophy |
| Left and right hemisphere joined by what? Anterior and posterior lobe separated by what? | Median vermis Primary fissure |
| 4 inputs into the cerebellum? Types of input fibres? | 3 inferior peduncle vestibular/reticular/inferior olivary nucleus 1 middle peduncle Cerebral cortex Climbing and mossy Climbing used for inferior olivary nucleus |
| Number of outputs of cerebellum to the spinal cord? Flocculo-nodular lobe? | 0 Loss of balance and co-ordination |
| Hereditary disease associated with the cerebellum? | Fredreich's ataxia |
| Clinical signs of cerebellar damage? | D-Dyskine A-ataxia N-nystagmus I-intention tremor S-Slurred speech H-Hypotonia P-Past pointing |
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