Phase 1 Neuro Flashcards
(47 cards)
5 vesicles of neural tube and what they become
From initial prosencephalon:
Telencephalon - cerebral hemispheres
Dienchephalon - thalamus
From initial mesencephalon -> midbrain
From initial rhomboencephalon
Metencephalon -> Pons and Cerebellum
Myelencephalon -> Medulla oblongata
In neural tube, what is ventral and what is dorsal in terms of sensory and motor?
Ventral - basal plate: Motor
Doral - alar plate: Sensory
The neural tube sometimes doesn’t close. What are the consequences cranially and caudally?
Cranially - anencephaly
Caudally - spina bifida
What are the types of spina bifida?
Oculta - Missing vertebral arch. no herniation of meninges/spinal chord. May have a patch of hair or dimple as only sign
Meningocoele - meninges (but not nerves), herniate.
Myelomeningocoele - spinal chord AND meninges herniate. Neurological signs present - e.g. paralysis below site/urinary/bowel incontinence.
Describe initiation of development of nervous system in utero
Notochord signals
Ectoderm starts to fold at cervical region and folding continues both ways
If problems, raised maternal alpha foetoprotein + USS
What is hydrocephalus?
Accumulation of CSF in brain because blockage
Neural crest cells migration - disorders?
Hirschsprung’s Disease (Aganglionic megacolon). Constipation.
DiGeorge
Thyroid problems, Thymus hence immune problems, Cardiac problems, Cleft palate
“CATCH-22”
Cardiac abnormality (commonly interrupted aortic arch, truncus arteriosus and tetralogy of Fallot) Abnormal facies Thymic aplasia Cleft palate Hypocalcemia/hypoparathyroidism
Layers of brain meninges: Outer to inner. Start from outside and cover SCALP.
Skin Connective tissue Aponeurosis Loose connective tissue Pericranium
Skull
Periosteal dura mater (flush with bone)
Meningeal dura mater (flush with ^ except certain parts where dural venous sinuses are)
Arachnoid mater (flush with ^, potential space only).
Subarachnoid space (with CSF)
Pia mater (tender mother) - flush with the brain. Chemical barrier.
Where do the dural venous sinuses drain?
Internal Jugular Vein
Ventricular system. Go.
CSF produced in chorioid plexuses. Mostly lateral ventricles -> Third Ventricle (squashed b/w thalami) -> cerebral aqueduct -> 4th ventricle -> Spinal canal.
Blockage anywhere causes proximal swelling. Hydrocephalus.
Purposes of CSF
Fluid buffer
Glucose
Cushioning
What pertinent anatomical landmark of the temporal lobe is important in ICP?
Uncus
Herniates and squashes breathy bits
Important nuclei in basal ganglia
Caudate (side of the lateral ventricle) and Lentiform (kind of triangular thing). Outer edge is the putamen, and inner is the globus pallidus.
Between the lentiform and thalamus is the internal capsule.
AMINO ACIDS
neurotransmitters
AMINO ACIDS
glutamate, GABA, glycine
BIOGENIC AMINES
neurotransmitters
BIOGENIC AMINES
acetylcholine, noradrenalin dopamine, serotonin (5-HT), histamine,
Peptide neurotransmitters
dynorphin, enkephalins, substance P, somatostatin cholecystokinin neuropeptide Y
Excitatory neurotransmitters
excitatory amino acids
– mainly glutamate
– majorexcitatoryneurotransmitter
• over 70% of all CNS synapses are glutamatergic • presentthroughouttheCNS
Inhibit neurotransmitters
• inhibitory amino acids – GABA
– Glycine
Why are NMDA receptors important for Long term potentiation
Glutamate receptors have an important role in learning and memory
– Activation of NMDA receptors (and mGluRs) can up-regulate AMPA receptors – Strong, high frequency stimulation causes long term potentiation (LTP)
– Ca2+ entry through NMDA receptors important for induction of LTP
GABA
Glycine
Mostly where
GABA brain
Glycine brainstem/spinal chord
alzheimers
Degeneration of cholinergic neurones in the nucleus basalis is associated with Alzheimer’s disease
What are the dopamine pathways in the brain and what are they involved with?
Mesocortical (mood)
Mesolimbic (Schizophrenia when too much dopa here, Amphetamines also increase dopamine and cause similar effects)
Nigrostriatal - Movement. Too little dopamine here causes Parkinson’s. Extra-pyramidal SEs also here.
Tuberoinfundibular - lactation (increased on risperidone)
Where, in the brain, is Noradrenaline made?
Locus ceruleus
Linked to wakefulness
Amphetamines increase NA (+Dopa), hence inc wakefulness
Mickey mouse midbrain anatomy
Head ventral
Chin Dorsal
Eyes - red nuclei
Nose - oculomotor nuclei + edinger westphal
Ears - cerebral peduncles (motor connection from brain to below)
Eyebrows - Substantia nigra - dopaminergic neurons involved in motor co-ordination
Tears - medial lemiscus (imp. in spinothalamic tract) Afferent fibres (sensation)
Mouth - cerebral aqueduct
Strawberry around mouth - periaqueductal grey - micturition and pain regulation
Chin - superior calliculus - reflexes