NLM2 Flashcards
What are the three subtypes of ionotropic Glutamate receptors?
NMDA, AMPA and Kainate
What does NMDA stand for?
N-methyl-D-aspartate
What does GABA stand for?
gamma-amino butyric acid
What does activation of GABA-A receptors induce?
Influx of Cl- into postsynaptic cell - hyperpolarisation - inhibition
What type of aphasia does a lesion of the arcuate fasciculus lead to?
Conductive - cannot repeat words said to them
Which 3 areas surrounding the internal capsule are part of the basal ganglia?
Putamen, Caudate Nucleus and Globus Pallidus
Which basal ganglia areas make up the striatum?
Caudate nucleus and Putamen.
What protein is lost in malignant neoplasms, allowing cells to break away and move around the body?
E-cadherin
What does PET scan stand for?
Positron Emission Tomography
What radioactive isotope is used in PET scans to see tumours (taken up by cells with high metabolic activity)?
F-flurordeoxyglucose
What is osteochondroma and what growth does it lead to?
A benign growth of the epiphysis, producing an outgrowth of bone covered by a cartilage cap.
Name 4 prion diseases
Creutzfeldt-Jakob Disease
Gerstmann-Straussler-Sheinker syndrome
Kuru
Fatal Familial Insomnia
Which 4 areas of the brain do not have BBB lining the blood vessels?
Median eminence, neurohypophysis, area postrema and pineal body
What are the 4 functions of the BBB?
Maintain constant microenvironment,
protect from exogenous toxins,
retain neurotransmitters
Modulate entry of metabolites
What are three functional differences between BBB and normal endothelium?
Impermeable to most substances
Sparse pinocytic vesicular transport
Increased receptor-mediated endocytosis
What three layers make up the BBB?
- Brain microvascular endothelial cells
- Astrocyte end feet
- Pericytes
What are the three types of glial cells in the brain and what is each of their function?
Astrocytes - support neurons, homeostasis, form BBB
Oligodendrocytes - produce myelin sheath
Microglia - resident brain macrophage
What is otosclerosis?
New bone forms around foot process of stapes and calcifies, fixing it in place
What is Glue Ear?
A build up of fluid in the middle ear due to the Eustachian tube not opening.
What are the two subtypes of hearing loss?
Conductive (ear canal/middle ear) and sensorineural (cochlea/nerve)
What is ataxia?
Problems coordinating movement (supplementary MC)
What is agnosia?
Problems understanding previously received sensory information (ASC)
What is Ménière’s disease?
Rare - recurrent bouts of unilateral attacks of aural fullness, hearing loss/tinnitus, sudden onset vertigo +/- NVD
Which drugs are the most likely to cause ototoxicity?
Aminoglycosides (gentamicin and streptomycin)
Name two vestibular sedative drugs (may lead to failed vestibular compensation - vertigo)
Stemetil and Stugeron
What does BPPV stand for? (audiology)
Benign Paroxysmal Positional Vertigo
What are the four branches of the ICA before it becomes the middle cerebral artery?
Hypophyseal (to pituitary)
Ophthalmic (branches inc retinal)
Anterior Choroidal (to LGN)
Posterior Communicating (to circle of Willis)
What are the 5 symptoms of anterior cerebral artery stroke?
Problems with personality and reasoning (PFC) Ataxia (SMC) Paralysis of LL (PMC) Sensory loss in LL (PSC) Agnosia (ASC)
What type of bond joins the two halves of an antibody?
Disulphide bond
What is the commonest type of primary brain tumour?
Glioblastoma
What types of sensation do the lateral and anterior spinothalamic tracts each carry?
Lateral - pain and temperature
Anterior - crude touch
What is the basis behind neuropathic pain?
Damage to nerves -> upregulation of Na channels -> pain
What do the neo- and palaeo-spinothalamic tracts each do?
Neo - initiates immediate awareness of painful sensation and localises pain
Palaeo - projects to limbic system for mediation of emotional responses and activates descending pain suppression pathways
Which 4 neurotransmitters are used in descending pain inhibition?
5-HT, Endorphins, Enkephalins and NA
Which protein complex holds vesicles of NT ready for release in pre-synaptic cells?
SNARE complexes
Name 2 cotransmitters, the NTs they act with and the actions they have.
Substance P - w/ glutamate, serotonin, ACh - binds to NK1-R and increases intracellular Ca2+ therefore amplifies NT action.
Enkephalin - w/ glutamate - opposite effect, prevents synaptic transmission therefore decreases NT action.
How do defensins kill microbes?
Disrupt membrane and inhibit DNA, RNA and protein synthesis.
How do interferons I and II defend against viruses?
Destruct viral mRNA, inhibit protein synthesis, upregulate MHC I, enhance Tcyt and activate NK cells
What is natural antibody?
Naive, non-specific, in circulation, serve as innate recognition receptors for bacterial cell wall components/parasites
Name 4 PAMPs (pathogen associated molecular pattern)
Flagellin, DNA, RNA, lipoprotein
Name the four types of innate pattern recognition receptors
Toll-like, Mannose, Complement and Scavenger
Name 6 DAMPs (damage associated molecular patterns)
Self DNA, Self RNA, mitochondrial contents, hyaluronic acid (ECM), uric acid, ATP
What two things are found in the granules from NK cells?
Perforins and granzymes
How many subunits is a nACh-R composed of?
5
How many molecules of ACh bind to each nACh-R?
2
What are the two categories of neuronal nACh-Rs, and are they homo or heteromeric?
a-bungarotoxin-sensitive : homemeric (5 identical subunits, either a7 or a9)
a-bungarotoxin-insensitive : heteromeric
What is lateral inhibition?
When pain signals dull down other incoming signals at PSC to increase contrast
What modality of sensation does the TTT-spinal nucleus V carry?
Crude touch, pressure, pain and temp from head.
Where does information travelling in the spinocerebellar tract originate from?
Muscle spindle fibres and Golgi tendon organs - non-conscious proprioception
What area of speech is a) Wernicke’s and b) Broca’s area involved with?
Wernicke’s - comprehension
Broca’s - production
What are the three types of subcortical fibres?
Association fibres - within one hemisphere
Commissural fibres - between hemispheres
Projection fibres - to outside brain
What function does the hippocampus have?
Converts short term to long term memory but DOES NOT STORE THEM.
What condition does damage to the hippocampus lead to?
Anterograde amnesia
What are 5 features of an UMN syndrome?
Spastic paralysis Clasp knife response Hyperreflexia Hypertonia \+ve Babinsky
What are 6 features of LMN syndrome?
Flaccid paralysis Atrophy (wasting) Fasciculations Hyporeflexia Hypotonia -ve (normal) Babinsky
What are the three pathological causes of stroke?
Cerebral infarction (85%), intracerebral haemorrhage, subarachnoid haemorrhage
How many genetic loci are there for MHC inheritance?
6
What is the name of the protein that holds open the MHC binding site for protein fragments in the ER?
Peptide loading complex
Which protein holds open the MHC II molecule binding site whilst it is being transported from the ER to the endosome? Which enzyme breaks this protein down?
He invariant chain, broken down by a CLIP enzyme
Which herpes virus causes chicken pox/shingles?
HHV3
Which herpes virus causes glandular fever (Epstein-Barr)?
HHV4
How many human herpes viruses are there?
8
What term is given to a virus’s ability to persist within a host in a dormant form for react ovation at a later time?
Latency
What two main diseases can CNS herpes cause?
Meningitis and encephalitis
What is the process by which infected tissue is surgically removed from around a prosthetic joint?
Debridement
What is it called when infection spreads from adjacent soft tissue?
Contiguous infection
What pathology does CJD lead to?
Widespread spongiform vacuolisation of the grey matter
Which are the three major monoamine neurotransmitters?
Serotonin, dopamine and NA
Outline the 7 steps in migraine
Triggers -> blood vessel dilation via NO -> activation of brain mays cells -> release of inflammatory mediators -> irritation of sensory nerves (pain) -> blood vessel relaxation -> increased blood flow and vascular leak
What are 4 possible visual aura symptoms of migraine?
Scotomata (alteration in visual field)
Hemianopia
Teichopsia (luminous outline)
Fortification spectra (zigzag scotomata)
Which cranial nerve branch is tested by the corneal reflex?
Nasociliary branch of ophthalmic division of trigeminal
What is the MLF?
Medial Longitudinal Fasciculus - connects cranial nerve nuclei of III and VI (and IV) to integrate eye movement
What is the name for the electrochemical environment of the brain?
Milieu
What type of epithelium lines the choroid plexus and secretes CSF?
Polarised columnar
What is the normal value of ICP?
15mmHg
What is the equation for cerebral perfusion pressure (CPP)?
CPP = MAP-ICP
What is the other name for Benign Intracranial Hypertension and what are the symptoms?
Pseudotumour Cerebri which leads to headaches, transient visual obscurations, diplopia, dizziness and vomiting
What is the main factor leading to the immune privilege of the brain?
Lack of MHC II and DCs so no antigen presentation
What is the name of the tiny sounds produced by outer hair cells in the cochlea?
Oto-Acoustic Emissions
Starting with stimulation of the auditory nerve, what is the (inclusive) 7 step pathway to the auditory cortex?
Auditory nerve Cochlear nuclei Superior olive Lateral lemniscus Inferior colliculus Thalamus Auditory cortex
What is acoustic neuroma? And what is it also known as?
Benign tumour of sheath of vestibular nerve leading to hearing loss and tinnitus. Also known as vestibular schwannoma
If the hair cells in the ear move towards the Kinocilium, does stimulation or inhibition occur?
Stimulation
What are the two otoliths organs and what do they sense?
Maculae in utricle and saccule - sense gravity and linear acceleration.
What do the cristae in the ampullae of the semicircular canals sense?
Angular acceleration.
What is antigenicity?
The ability to COMBINE with a product of immune responses (antibody/cell surface receptor)
What happens in colliquative/liquefactive necrosis.
Lack of blood supply -> cells die -> macrophages remove dead tissue -> fluid-filled cyst remains
What do each of the Igs (G,M,A,E,D) do?
G - opsonisation, classical pathway M - classical pathway, B cell receptor A - mucosal defence, lectin/alternative pathways E - mast cell degranulation D - B cell antigen receptor
In immunology, what is ADCC?
Antigen-dependent cell-mediated cytotoxicity
What is a zymogen?
A pro-enzyme that requires cleavage to form complement
What is SCID and what does it lead to?
Severe Combined Immunodeficiency due to failed maturation of T cell precursors within marrow. Leads to persistent diarrhoea and failure to thrive and unusual infections
Which molecules normally regulated the free radicals released from mitochondria to prevent them from harming the cell?
Superoxide dismutases (Cu/Zn/Mn SODs) Glutathione peroxidases
Through which 3 parts of the brain does the Reticular Activating System exist? What 5 things does it release?
Group of nuclei in the midbrain, upper pons and posterior hypothalamus.
ACh, NA, serotonin, histamine, orexin
Which nucleus in the hypothalamus is the biological clock?
Suprachiasmatic nucleus
Which are the three main nuclei involved with sleep?
Raphe nuclei,
Suprachiasmatic nucleus
Nucleus of solitary tract
What is DAI?
Diffuse Axonal Injury - widespread tearing/disruption of axons in the white matter
What is it called when brain herniations cause brainstem compression resulting in damage to vital centres?
Coning
Which nerve carries the sense of taste?
Chorda tympani of CNVII
Which three sinuses drain into the middle meatus?
Frontal, maxillary and anterior ethmoidal
Where does the sphenoid sinus drain to?
Sphenoethmoidal meatus (recess)
In MS, accumulations of which protein lead to blockage in neurons?
Amyloid precursor protein
In regeneration of peripheral nerves, which two molecular factors drive Schwann cell proliferation?
LIF (leukaemia inhibitory factor) and Reg2
What are the three phases involved with swallowing?
Buccal
Pharyngeal
Oesophageal
Which product of Vit A produced in the gut is used as a chemokine receptor (CCR9) organ-specific migration pattern?
Retinoic acid
In immunology, what are ITAMs, and what does phosphorylation of them lead to?
Immunreceptor Tyrosine-Based Activation Motif
Phosphorylation pushes away the phosphatases that normally inhibit the kinases allowing micro clustering of TCRs
Name 4 causes of CNS axonal degeneration
Traumatic brain injury
MS - inflammatory injury
Stroke - ischaemic injury
Alzheimer’s - altered cytoskeletal proteins
What are the four theories as to why we sleep?
Inactivity theory
Energy conservation theory
Restorative theories
Brain plasticity theories
Which two areas are part of the wakefulness-promoting system and what NT act there?
Locus coeruleus (NA) Tuberomamillary nucleus (histamine)
Where is the sleep-promoting system found? And which NT acts?
Ventrolateral preoptic nucleus of hypothalamus (VLPO) - GABA
What technique is used to objectively measure sleep patterns?
Polysomnography (PSG)
Name 4 diseases predisposed to polygenically
Hypertension, cholesterol, stroke, dementia
Name a disease that is due to a submicroscopic deletion or duplication.
Charcot-Marie-Tooth Disease - neuropathy
What type of genetic mutation leads to Huntingtons’s?
CAG triplet expansion on Chr 4
Which cells, in which layer of the cortex, does the corticospinal tract arise from?
Betz cells in cortical layer 5
What is the definition of a seizure?
A paroxysmal (sudden, random) discharge of cerebral neurons causing clinically detectable signs.
What are the 3 most common causes of dementia?
Alzheimer’s Disease
Dementia with Lewy Bodies
Vascular Dementia
