Neuroanatomy Flashcards
What parts of skull are in Anterior Middle Posterior cranial fossae?
Anterior- Frontal, ethmoid, lesser wing of sphenoid
Middle- temporal lobes and includes the greater wing of the sphenoid, sella turcica, and the majority of temporal bones.
Posterior- occipital lobes, cerebellum, and medulla and includes the occipital bone.
Serotonin.
Two steps involved in making it?
Transformation of L-tryptophan into serotonin involves two steps:
Hydroxylation to 5-hydroxytryptophan catalysed by tryptophan hydroxylase
Followed by decarboxylation of 5-hydroxytryptophan to serotonin (5-hydroxytryptamine) by L-aromatic amino acid decarboxylase
Serotonin.
Made from what?
Where made?
It is synthesised from the amino acid L-tryptophan which is obtained from the diet raphe nuclei (in the brainstem) also in the GI tract (enterochromaffin cells)
Kluver-Bucy Syndrome
- which part of brain affected?
- which structure implicated?
- features?
- most common causes?
- medial temporal lobes
- amygdala
- Hyperorality (tendency to explore object with the mouth), Hypersexuality, docility, visual changes, dietary changes
- alzheimers, herpes, FTD, trauma, bilateral temporal lobe infarction
4 macroscopic changes in alzheimers
cerebral atrophy
hippocampal atrophy
low brain weight
enlargement of inferior horn of lateral ventricle
4 microscopic findings in alzheimers
hirano bodies tangles of tau protein amyloid beta plaques gliosis degeneration of nucleus of meynert
what are the four types of afferent axon?
which is unmyelinated?
A-alpha (proprioception)
A-beta (touch)
A-delta (pain and temperature)
C (pain, temperature, and itch)
C is unmyelinated
What are the main subtypes of neurotransmitter and give examples.
Small molecules-Acetylcholine, Dopamine, Norepinephrine, Serotonin, Histamine, Epinephrine
Amino acids- GABA, glutamate, glycine, aspartate
Peptides- prolactin, oxytocin
Soluble gases- nitric oxide, carbon monoxide
BBB
Why does it have areas of fenestration?
Name 4 of these areas?
At several areas the BBB is fenestrated to allow neurosecretory products to enter the blood. These areas are known as circumventricular organs and include:-
Pineal body Posterior pituitary Area postrema Subfornical organ Vascular organ of the lamina terminalis Median eminence
Broca’s Aphasia - broken or non? Brodman area?
Wernicke’s Aphasia - broken or non? Brodman area?
Broca’s: broken. Brodman area 44, 45.
Wernicke’s: non-broken. Brodman area 22.
What are the three groups of white matter tract?
Give examples of each.
Projection. From higher centres to lower centres e.g. corticospinal, corticobulbar, optic radiation, internal capsule and corona radiata.
Commisural. Connects the two hemispheres together. e.g. anterior commisure (links the temporal lobes), corpus callosum
Association. Connects lobes from within the same hemisphere. e.g. cingulum, uncinate, and all the fasciculus ones
Brain development:
What are the three main parts of brain development?
prosencephalon - split into diencephalon (thalamus and similar structures) and telencephalon (cerebrum)
Mesencephalon - bunch of stuff including cerebral peduncles + midbrain
rhombencephalon - split into metencephalon (pons, cerebellum) and myelnencephalon (medulla)
Brain lobes and dysfunction
Frontal Contralateral hemiplegia, impaired problem solving, disinhibition, lack of initiative, Broca’s aphasia and agraphia (dominant)
Temporal Wernicke’s aphasia (dominant), homonymous upper quadrantanopia, auditory agnosia (non-dominant)
Parietal lobe (non-dominant) Anosognosia, dressing apraxia, spatial neglect, constructional apraxia
Parietal lobe (dominant) Gerstmann’s syndrome (agraphia, acalculia, finger agnosia and left-right disorientation), Occipital lobe Visual agnosia, visual illusions, contralateral homonymous hemianopia
CSF
describe the flow including names of passageways.
which two layers is it between?
normal pressure?
big differences in constituency between CSF and plasma?
- lateral ventricles to third by foramen of munro. third to fourth by aqueduct of sylvius.
- arachnoid and pia.
- 5-15mmHg.
- most things lower. magnesium and chloride are higher. sodium is unchanged.
When does process of myelination begin?
Last area to become myelinated?
What forms myelin in CNS/PNS?
14 weeks
Frontal lobes
Schwann cells in peripheral, oligodendrocytes in central
What do each of the dopamine pathways do?
Mesolimbic pathway - therapeutic benefit
Mesocortical pathway - negative symptoms
Nigrostriatal pathway - EPSE’s
Tuberoinfundibular pathway - hyperprotactinemia
Steps in dopamine synthesis.
Tyrosine –> L-Dopa
( tyrosine hydroxylase)
L-Dopa –> dopamine
(dopa decarboxylase)
What type of receptors are dopamine receptors?
What do each type do?
Dopamine receptors are a class of metabotropic G protein-coupled receptors
There are five receptor subtypes D1, D2, D3, D4, and D5.
D1 and D5 are referred to as D1 like receptors. Increase cAMP
D2, D3, and D4 are referred to as D2 like receptors. Decrease cAMP
What passes through Foramen spinosum? Foramen ovale? lacerum? magnum? jugular foramen?
Foramen spinosum Middle fossa Middle meningeal artery
Foramen ovale Middle fossa Mandibular division of trigeminal nerve
Foramen lacerum Middle fossa Internal carotid artery
Foramen magnum Posterior fossa Spinal cord
Jugular foramen Posterior fossa Cranial nerves IX, X, and XI
What are the following gyri functions: Precentral Postcentral Angular Fusiform Cingulate ParaHippocampal Dentate Lingual Superior frontal Superior temporal
Precentral: movement Postcentral: touch Angular: mathematics, language, cognition Fusiform: recognition of body and faces Cingulate: emotion/learning/memory Parahippocampal- memory Dentate- memory Lingual - dreaming Superior frontal- laughter, self awareness Superior temporal- language (wernickes)
Utilisation behaviour, which lobe?
utilisation: described as reaching out and automatically using objects in the environment
frontal lobe issue
What breaks down serotonin?
What substances block the transporter than pick up serotonin from synapse (SERT)?
Block: MDMA, amphetamine, cocaine, TCA’s, and of course SSRI’s.
Broken down by MAO and aldehyde dehydrogenase.
Sarcoidosis
Clinical features?
How many get psychiatric features?
SOB (granulomas most often form in lungs), weight loss, fatigue, dry eyes.
20%.
Match the finding to a condition:
- Papp Lantos Bodies.
- Asteroid bodies.
- Mallory bodies.
- Papp Lantos Bodies are found in Multi-Systems Atrophy.
- Asteroid Bodies are found in sarcoidosis.
- Mallory boides are found in alcoholic hepatitis, alcoholic cirrhosis, Wilson’s disease, primary-biliary cirrhosis
Action Potential
- What is the original state of play that holds a cell in resting state?
- Membrane potential resting state?
- What does it get to to fire an AP?
- What happens here?
- Where does it reach? What then happens for repolarisation?
- More Na OUT the cell. More K IN the cell.
- Resting state is -70
- -55
- Na enters cell
- Reaches +40. Then K channels open and leaves.
Name 5 ionotropic receptors.
Name 5 metabotropic receptors.
5 ionotropic receptors: GABA-A, nicotinic acetylcholine, 5HT3, glutamate, glycine
5 metabotropic receptors: GABA-B, muscarinic acetylcholine, serotonin (other than 5HT3), dopamine, adrenergic
When it comes to receptors,
what does the term potency mean? what 2 things make up the potency?
intrinsic?
potecncy: the concentration or dose of a drug required to produce 50% of the drug’s maximal effect. depends on both affinity of a drug for its receptor and efficiency with which drug-receptor interaction is coupled to response
efficacy: also referred to as ‘intrinsic activity’ of a drug is the ability of the drug to elicit a response when it binds to the receptor
Glycine is a _____ neurotransmitter?
It is antagonised by?
inhibitory (alongside GABA it is the other big inhibitory one)
strychnine
Reflexes; what are the sensory/motor components: Pupillary Accomodation Jaw Jerk Corneal Vestibulo-ocular Gag
Reflex Sensory component Motor component Pupillary light reflex Optic Oculomotor Accommodation reflex Optic Oculomotor Jaw jerk Trigeminal Trigeminal Corneal reflex Trigeminal Facial Vestibulo-ocular reflex Vestibulocochlear Oculomotor, trochlear, abducent Gag reflex Glossopharyngeal Vagus
Components of Gerstmanns?
Which kind of lesion?
Dominant parietal lobe. Dysgraphia (can't read) Dyscalculia (can't do simple maths) Finger agnosia (can't identify specific fingers) Right-left disorientation
What do you get with non-dominant parietal lobe lesions?
anosognosia (lack of awareness of a disability or disease) dressing apraxia (difficulty in getting dressed) spatial neglect (lack of awareness of one side of the body) constructional apraxia (inability to copy pictures or combine parts of something into a meaningful whole)
What syndrome is it with bilateral parietal lobe issues?
Balints. ocular apraxia (difficulty keeping the eyes still) optic ataxia (difficulty moving the eyes to a specific position) simultanagnosia (inability to simultaneously perceive the different aspects of a picture and appreciate it as a whole)
What is serotonin broken down to?
5-Hydroxyindoleacetic acid (5-HIAA).
What types of speech problem (dysarthria) do you know?
Site of the lesions?
Conditions involved?
Features of the speech?
Type Features Associated conditions Localisation
Spastic Explosive and forceful, at a slow rate Pseudobulbar palsy, spastic hemiplegia Upper motor neuron
Flaccid Breathy, nasal voice, imprecise consonants Myasthenia gravis Lower motor neuron
Hypokinetic Slow, quiet, with a tremor Parkinson’s disease Extrapyramidal
Hyperkinetic Variable rate, inappropriate stoppages, strained quality Huntington’s disease, Sydenham’s chorea, tardive dyskinesia Extrapyramidal
Ataxic Rapid, monopitched, slurred Friedreich’s ataxia, alcohol abuse Cerebellum
Cerebellum.
Divided by cerebrum by?
How many physical lobes? Names?
How many functional lobes? Functions?
Tontorium cerebelli.
Ant, post and flocculonodular
Ant and post have medial (spoinocerebellar) and lateral (cerebrocellebar) areas. Vestibulocerebellum is the FNL.
Functions-
spinocerebellum - fine tuned body movement
cerebrocerebellum - planning movement
vestibulocerebellum (FNL) - balance/spatial orientation
3 features of MSA
3 presentations
microscopic features
macroscopic features
parkinsonism, autonomic failure, ataxia
Shy-Drager Syndrome (mainly autonomic features) Striatonigral degeneration (mainly Parkinson features) Olivopontocerebellar atrophy (mainly cerebellar features)
papp lantos bodies
Pallor of substantia nigra
Greenish discolouration and atrophy of the putamen
Cerebellar atrophy
Occlusions of arteries and effects
Anterior Cerebral Artery
MCA
PCA
ACA:
Hemiparesis of the contralateral foot and leg (more severely than the arm)
Sensory loss of the contralateral foot and leg
Motor dysphasia
MCA:
Hemiparesis of the contralateral face and limbs
Sensory loss of contralateral face and limbs
Dysphasia (when dominant hemisphere affected)
Contralateral neglect
Homonymous hemianopia or quadrantanopia
Dorsolateral prefrontal dysfunction
PCA:
Alexia without agraphia (left PCA)
Contralateral loss of pain and temperature sensation
Contralateral hemianopia
Prosopagnosia
Ipsilateral cranial nerve defects (V, VIII, IX, X, & XI)
Horner’s syndrome
4 hormones that effect hunger
Neuropeptide Y is produced by the hypothalamus and increases appetite
Leptin is produced by adipose tissue and reduces appetite
Ghrelin is produced mainly by the gut and increases appetite
Cholecystokinine (CCK) is produced mainly by the gut and reduces appetite
Alexia without agraphia?
Alexia without agraphia = Infarct to left PCA
Can write but not read
What agnosias do you know
Prosopagnosia Inability to recognise familiar faces
Anosognosia Inability to recognise own condition/ illness
Autotopagnosia Inability to orient parts of the body
Phonagnosia Inability to recognize familiar voices
Simultanagnosia Inability to appreciate two objects in the visual field at the same time
Astereoagnosia Inability to recognize objects by touch
anton babinski affects which area
Anton’s syndrome (aka Anton-Babinski syndrome) occurs following damage to the occipital lobe.
Affected individuals are cortically blind but are unaware of this and deny they have a problem (anosognosia).
Main site of norepinephrine release?
locus coeruleus (aka ‘the blue spot) which is located in the pons.
What triggers the release of neurotransmitter into a synaptic cleft?
An action potential that causes calcium channels to open.
The influx of calcium leads to the release of neurotransmitter.
What are the functions of the following: Nissl Substance. Golgi apparatus Mitochondria Microfilaments Lysosomes Melanin
Nucleus Contains the nucleolus and chromosomes
Nissl substance Consists of rough endoplasmic reticulum (with free ribosomes) and is the site of protein synthesis
Golgi apparatus Modifies, sorts, and packages macromolecules for cell secretion (exocytosis) or use within the cell
Mitochondria Involved in energy production
Microfilaments and microtubules Used for structural support and transportation within the cell
Lysosomes Spherical bodies containing digestive enzymes which break up cellular debris and protect against threats such as viruses
Melanin Function unknown, possibly a by-product of neurotransmitter synthesis
What percentage of temporal lobe seizures are preceded by aura?
What auras do you know? 2 types.
What kind of aura could precede a parietal lobe partial seizure?
An occipital seizure?
80%
abdominal (a rising epigastric sensation) and psychic aura (fear, déjà vu, jamais vu).
Parietal lobe seizures may begin with a contralateral sensation
Occipital lobe seizures may begin with contralateral visual changes, usually of the positive type, such as colored lines, spots, or shapes, or even a loss of vision
Support cells aka glial cells of the nervous system functions:
Astrocytes
Oligodendrocytes
Ependymal cells
Microglia
Astrocytes- have numerous functions including structural support, repair of nervous tissue, providing nourishment to neurons, contributing to the blood brain barrier, neurotransmission, and vasomodulation. There are two main types, protoplasmic and fibrous.
are responsible for the formation of myelin sheaths.
line the ventricular system and are involved with CSF circulation and fluid homestasis in the brain. Specialised ependymal cells call choroid plexus cells are responsible for CSF production.
are the immune cells of the CNS.
As well as Brocas and Wernickes aphasia, we need to know about two others:
Conduction aphasia
Anomic aphasia
Conduction
Form of fluent aphasia
Poor repitition is the hallmark
Lesion is arcuate fasciculus
Anomic
Naming or word finding problems are the major feature of the syndrome
The lesion is often temporal parietal area. Or angular gyrus
Another fluent aphasia
Prosopagnosia. Where is the lesion?
Fusiform gyrus
What blood supply of caudate nucleus?
Supplied by deep penetrators of anterior and middle cerebral arteries.
Name the four prion diseases;
Creutzfeldt-Jakob disease
Kuru
Gerstman-Straussler-Scheinker syndrome
Fatal familial insomnia
Melatonin:
Synthesised by what?
Where?
Melatonin is synthesised in the pineal gland from serotonin. Melatonin released is enhanced in dark environments (e.g. during the night).
