Mini 3 - Neuro Flashcards
Describe the posterior cerebral artery.
Big, supplies the medial and inferior surfaces of the occipital and temporal lobes, sends branches to rostral midbrain and caudal diencephalon, gives rise to posterior choroidal arteries (supply choroid plexus of 3rd and lateral ventricle).
Where is the accessory nucleus?
Spinal cord.
What is the difference betwen aknesia and dyskinesia?
Absence/poor movement vs fragmentary/incomplete movement.
What do you get if you knock out the left hemisphere (in most people)?
Minimal right neglect.
Describe the pathway for spoken and written language.
Auditory cortex or visual (then auditory) cortex. Then Wernicke’s area, the Broca’s via arcuate fibers. Then primary motor cortex.
What is syringomyelia?
Enlargement of the central spinal cord. Usually causes ‘cape-like’ loss of pain and temperature by the C5 dermatome, but really it can be anything depending on the lesion.
What does layer IV of the neocortex do?
Gets input from the thalamus.
What are stellate cells excitatory/inhibitory on?
Inhibitory on Purkinje dendrites.
What kind of drugs are gabapentin and pregabalin, how does it work and what kind of pain does it treat?
Structural analogues of GABA but no effect on GABA receptors! THey inhibit presynaptic N, L, P/Q type VG Ca++ channels containing alpha2delta subunits. Treat neuropathic pain, also epilepsy. Gabapentin can also treat postherpathic neuralgia, pregabalin ca also treat pain associated with diabetic peropheral neuropathy, SC injury,fibromyalgia, or also postherpertic neuralgia.
What is the pain threshold of sound?
120dB. 150 can rupture the tympanic membrane.
What are the second order neurons in the olfactory epithelium? And what tracts do they form and where do they project to?
Mitral cells (form lateral olfactory tract) and synapse with the primary olfactory cortex. Tufted cells (form medial olfactory tract) projects bilaterally to the basal forebrain.
How is interaural intensity difference processed?
By the lateral superior olive. Signal goes to the ipsilateral LSO and then to the contralateral medial nucleus of the trapezoid body (sends inhibitory signals to its own LSO).
What are the lobes of the cerebellum?
Anterior, posterior, flocculonodular. There is also the vermis down the midline.
What is the spinomesencephalic tract?
Spinothalamic but it synapses at the end at the periaqueductal gray.
How are salty and sour tastes received?
Na+ through ion channel and H+ through ion channel.
What type of neurotransmission does Haloperidol work on and how?
Dopaminergic. D2 antagonist.
Describe saccades.
FEF initiates saccades - talks to ipsilateral superior colliculus, talks to contralateral PPRF, which talks to CN VI. CN VI talks to the ipsilateral lateral rectus and the contralateral CN III (medial rectus) via MLF.
What does the Suprachiasmatic nucleus do?
Projects indirectly to the pineal gland and controls its synthesis of melatonin.
What is in the posterior area of the hypothalamus?
Mammillary bodies (learning and memory), Posterior nucleus (thermoregulatory, conserves heat), Tuberomammillary nucleus (histaminergic, important in wakefulness and arousal).
What syndromes can come from occlusion of the posterior cerebral artery?
Superior alternating / Weber’s / Medial midbrain. Affects CN III and corticospinal axons - can cause alternating hemiplegia. Also Benedikt’s syndrome - same as Weber’s plus ataxia (tegmental regions of midbrain also affected).
What does lack of sleep predispose someone to?
Viral infections, weight gain, diabetes, high BP, heart disease, mental illness, mortality.
Where is the mesencephalic nucleus?
The midbrain to the upper pons.
What is Meniere’s disease?
Attack of rotational vertigo, unilateral/bilateral hearnig loss, tinnitus, pressure in both ears.
Describe the basal ganglia indirect pathway.
Cortex excites striatum, inhibits GPe, inhibits STN, excites GPi, inhibits thalamus, excites cortex. Net inhibition to cortex.
What’s the difference between drug misuse and drug abuse?
Use for medicinal purposes but wrong vs use for non-medicinal purposes.
What are commissural fibers? What are the different types?
Primarily I-III layers, interconnect homologous areas of two hemispheres. Corpus callusum, anterior commissure, posterior commissure.
Which neurotransmitter receptors mediate most of the fast excitatory neurotransmission in the CNS?
Glutamatergic.
What is the Limbic cortex loop?
Limbic cortex to nucleus accumbens to ventral globus pallidus to Dorsomedial nucleus of the Thalamus.
Where are the Cochlear nuclei?
Mid-medulla.
What does layer V of the neocortex do?
Outputs to striatum, brainstem, and spinal cord.
What are the reflex grades?
2+ is normal, 1+ is hypoactive, 0 is absent, 3+ is hyperactive without clonus, 4+ is hyperactive with clonus.
What type of neurotransmission does Nitrous oxide work on and how?
Glutamatergic. NMDA antagonist.
What are layers 3-6 from the LGN?
Parvocellular layers - deal with colour and form - midget ganglion cells.
Which visual pathways identify ‘what’ and ‘where’?
From the virual cortex, the dorsal path identifies ‘where’ and the ventral path ‘what’.
What is the Thalamus made up of?
A, M, L lobes divided by internal medullary lamina. 2 halves of the thalamus connected by massa intermedia.
Anterior lobe - anterior nucleus
Medial lobe - dorsomedial nucleus
Lateral zone - VA, VL, VPM, VPL ventrally; Pulvinar, lateral posterior, lateral dorsal dorsally
Also LGN and MGN
What type of neurotransmission does Sumatiptan work on and how?
Serotonergic. 5HT1 B/D agonist.
Where is the olfactory association cortex?
The orbital gyri of the prefrontal cortex.
How is ACh made?
Choline (nitrogen-containing alcohol) acetylated via choline acetyltransferase.
What is a MEG?
Magnetic encephalogram. Records miniscule magnetic signals made by neural activity, better localization of activity than EEG.
What type of receptor is the beta1 receptor, what does it respond to, and by what mechanism does it work and is it excitatory of inhibitory?
Responds to adrenaline. Metabotropic. Increase of cAMP, decrease in K+ conductance. Excitatory.
What is the Rinne Test?
Compares air vs bone conduction. Normal is AC>BC. Conductive loss is BC>AC, sensorineural loss is AC>AC but both decreased.
What are golgi cells excitatory/inhibitory on?
Inhibitory on mossy fibers.
What does the vestibulospinal tract do?
Lateral facilitates alpha and gamma motor neurons that facilitate extensors, maintaining posture. Medial causes rotation/lifting of head as well as rotation in the scapula.
What is the cause of Parkinson’s? Describe it. How do you treat it?
SNc degeneration (degeneration of nigrastriatal pathway). Hypokinetic, tremor, rigidity, etc. Symptoms present at 90% neuron loss. Give Levodopa and Carbidopa, D2 agonists, selective MAO-B inhibitors.
What are the derivatives of the diencephalon?
Thalamus, hypothalamus, epithalamus, pituitary, pineal, optic vesicle. Also third ventricle.
Where is the main input of the vestibulocerebellum and what deep cerebellar nucleus does it work with?
Main input semicircular canals and vestibular nuclei, works with fastigial.
Where is a lumbar puncture done?
L3/L4 in adults, L4/L5 in children.
Describe Merkel’s discs.
Superficial, slowly adapting. Allow for 2pt discrimination.
What’s the only cranial nerve nucleus that innervates the opposite side.
The trochlear nucleus.
What is drug tolerance and what are the types?
Decreasing body response to the action of a drug that usually results from prior exposure. Pharmacokinetic tolerance is due to the decrease of the effective concentration at the site of action. Pharmacodynamic tolerance is due to homeostatic adaptive changes that counteract the drug effect, changes in number or properties of the receptor.
What’s special about frontal lobe lesions?
They can cause contradictory symptoms in different people. Frontal lobe deals with restraint, initiative, order.
Where do signals go from the dentate nucleus?
Through the SCP, across the midline, synapses on the VL of the thalamus.
What does the Romberg Test test?
Dorsal column proprioception NOT cerebellar function. Person with damage sways with closed eyes.
What is dysdiadocokinesia?
Impairment of the ability to perform rapid alternating movements.
How many spinal cord injuries is alcohol involved in?
25%.
What are Betz cells?
Specialized layer V neocortex pyramidal cells.
Describe N3 of non-REM sleep.
Delta waves on EEG. Parasomnias (night terrors, bed wetting, somnambulism, somniloquy).
What are basket cells excitatory/inhibitory on?
Inhibitory on Purkinje soma.
Which phases of sleep predominate at what point?
First 1/3 N3, last 1/3 REM predominates. In infants REM is like 50% of sleep, at about 80 y/o the REM reduces.
What is alexia without agraphia?
Lesion in dominant occipital cortex prevents visual processing from right hemifield (right hemianopia).
Describe Ruffini endings.
Deep, slowly adapting. Respond to slide of skin against skin.
Where do the ampullae of the semicircular canals project to?
SVN and rostral MVN.
Describe an epidural hematoma.
Lens shape, bounded by sutures, can cross midbrain. Caused by the meningeal artery or dural venous sinus.
What kind of drug is amitryptilline, how does it work and what kind of pain does it treat?
A tricyclic antidepressant (1st gen). Blocks uptake of serotonin and NorE. Treats neuropathic pain (fast action) - and also major depressive disorder.
What are the exceptions of the corticobulbar tract?
It’s generally bilateral innervation with contralateral dominance except for CN VII (ventral nucleus only contralateral), CN XI (only ipsilateral), CN XII (only contralateral).
What hormones peak in what states of consciousness?
Growth hormone and melatonin in sleep (though at different times), and cortisol in waking.
What is Parinaud’s syndrome?
Lesion of dorsal midbrain and pretectal area. Loss of vertical gaze, dilated and irregular pupils with Argyll pupils. Collier’s sign (upper eyelid retraction) and convergence retraction nystagmus.
What does the reticulospinal tract do?
Lateral inhibits voluntary or cortically produced movements, medial facilitates them. Both act on gamma motor neurons. Fibers contribute to spasticity in patients with corticospinal damage or to tonic extension of extremities in patients with decerebrate rigidity.
What is Brown-Sequard syndrome?
1/2 spinal cord lesion - lose ipsilateral touch and motor, contralateral pain and temperature.
Where is the organ or Corti?
In the cochlea.
What do layers I-III of the neocortex do?
Receive input from cortex and outputs to other areas of the cortex.
Where does the cuneocerebellar pathway get info from?
Upper limb and neck.
What kinds of drugs are Aspirin (acetylsalicylic acid) and Ibuprofen? How do they work?
NSAIDs. Inhibit COX1 and COX2 (convert arachidonic acid to prostaglandins). Aspirin is irreversible, ibuprofen is competitive.
What is internuclear ophthalmoplegia?
MLF syndrome. Lesion between CN VI and III. Knocks out ipsilateral adduction. Convergence is intact.
Where do the microglia derive from embryologically?
Not neuroectoderm! Mesenchyme.
Describe the periaqueductal gray raphe nuclei tract / raphespinal tract.
Gets info from the limbic system, starts from PAG, synapses in the medullary nucleus raphe magnus. Then synapses at a Lamina II interneuron. Lamina II neuron inhibits Lamina V spinothalamic neurons and suppresses pain.
What is decerebrate rigidity?
All extensors rigid, red nucleus influence removed. Medial rubrospinal and lateral vestibulospinal the cause. Reticulospinal involged.
What does the anterior commissure connect?
Olfactory nuclei, amugdala, anterior temporal lobes.
What is an aneurysm?
Swellings of the arterial wall (usually at the bifurcation) - can compress brain structures.
Where is the facial nucleus?
The lower pons.
What is agnosmia?
Loss of verbal ability to classify/identify odours.
What ganglia from the taste cranial nerves are involved in synapsing to the nucleus solitatius?
VII - geniculate IX - petrosal X - nodose
What is the cause of Hemiballismus? Describe it.
Damage to the contralateral STN. Hyperkinetic. Sudden, wild flailing of one arm +/- ipsilateral leg.
What is the FEF Brodmann number?
8
What modalities does CN X transmit and what nuclei are they associated with?
All 5! BE (Nucleus ambiguus). GVE (Dorsal motor nucleus of X). SVA&GVA (Nucleus solitarius). GSA (Main sensory and spinal nucleus of V).
Where is the Subthalamus and what is it made up of?
Inferior to thalamus, lateral to hypothalamus, medial to internal capsule and cerebral peduncles. STN, Substantia Nigra, Red Nucleus, Zona Incerta.
How do you tell AICA from PICA occlusion?
Nucleus ambiguus/solitarius only affected in PICA (taste issues). Motor/sensory nucleus of V and facial nucleus only affected in AICA (jaw deviation, face issues).
Where does the anterior spinocerebellar pathway get info from?
Distal lower limb, transmits muscle spindle and golgi tendon organ afferent info.
When is the highest incidence of a DVT complication of spinal cord?
72hrs-14 days after.
What are the layers of the neocortex?
I (molecular), II (external granular), III (external pyramidal), IV (internal granular), V (internal pyramidal), VI (polymorphous).
What is Lateral medullary syndrome and what is another name for it?
Wallenberg’s syndrome. Occlusion of the PICA. Affects spinothalamic, descending tract of V, inferior cerebellar peduncle, descending sympathetic fibers (Horner’s syndrome), cochlear nuclei, nucleus solitarius, nucleus ambiguus.
What is the production of new neurons and the destruction of neurons called?
Neurogenesis and neurodegeneration.
How does Lidocaine work?
Blocks inactivated VG Na+ channels.
What is the dominant hemisphere for language?
Left usually (90% of right handed and 70% of left handed people). Left handed people also often have some bilateral.
What is reelin? What do mutations in it result in?
An ECM protein needed for neuronal migration termination. It’s secreted by early born neurons ‘Cajal-Retzius cells’. A mutation in it causes Norman-Roberts syndrome - inverted cervical lamination, cerebellum underdevelopment, cranio-facial abnormalities. LIS2 lissencephaly.
What are the types of apraxia?
Ideomotor (can’t do an imaginary action), Ideational/conceptual (inability to conceptualize and complete multi-step task or voluntarily perform learned task). Constructional (inability to copy drawings).
What type of receptor is the beta2 receptor, what does it respond to, and by what mechanism does it work and is it excitatory of inhibitory?
Responds to adrenaline. Metabotropic. Increase of cAMP. Inhibitory.
When does neurulation occur?
Week 3 and 4.
Where are the Vestibular nuclei?
Pons and upper medulla.
Describe the brain orienting axes.
Rostral/caudal is A/P axis. Dorsal is superior, ventral is inferior.
What arteries are connected in the circle of Willis?
Anterior cerebrals, internal carotids, posterior cerebrals.
What type of neurotransmission does Benztropine work on and how?
Cholinergic. M1 antagonist.
Where do the maculae of the semicircular canals project to?
Terminate in LVN, saccular macula also projects to IVN.
Describe the posterior spinocerebellar pathway.
DRG via fasciculus gracilis, to Clarke’s nucleus. Travel via distal spinocerebellar tract in lateral funiculus through inferior cerebellar peduncle into cerebellum.
What is the response in caloric testing for a bilateral MLF lesion?
No adduction, only abduction. Moves towards cold water and away from warm.
Where is the lumbar cistern?
From the conus medullaris to about S2.
What are the name of the ten sections the grey matter of the spinal cord can be divided into?
Rexed’s Laminae, I being most dorsal.
Which of the meninges are vascular?
Dura mater (own blood supply) and also pia mater. Arachnoid mater is avascular.
Where is the superior salivatory nucleus?
Lower pons.
Describe the superior cerebellar artery.
Supplies the cerebellum and some midbrain. Separated from posterior cerebral by CN III.
What type of neurotransmission do Atropine and Scopolamine work on and how?
Cholinergic. Muscarinic antagonist.
What is Freidrich’s ataxia?
Autosomal recessuve, hereditary, DC and lateral corticospinal degeneration.
What is subacute combined degeneration?
Lesions in the spinal cord due to a B12 deficiency, will affect DCML, lateral corticospinal tract. Spastic paralysis, hemiplegia.
Describe Broca’s vs Wernicke’s aphasia.
Broca’s has stop/start speech, non fluent. Wernicke’s is fluent but meaningless.
What is in the lateral area of the hypothalamus?
Lateral Nucleus - feeding center, regulates food intake (destructon=starvation), regulates drive states for pleasure and reward.
What kind of drugs are codeine and morphine, how do they work, and what effects do they have? (What kind of pain do they treat?)
Opioids (codeine is metabolized to morphine). They work at opioid - mu receptors. Presynaptically decrease Ca++ influx and postsynaptically increase K+ efflux. Analgesia, euphoria, miosis, constipation. (nociceptive).
What is the M-pathway?
The magnocellular layers will terminate on layer 4Calpha of the primary visual cortex.
What do the fasciculus gracilis and fasciculus cuneatus transmit?
Discriminative touch - gracilis T7 and below, cuneatus T6 and above.
What are the fibers in the genu of the internal capsule?
Corticobulbar, some thalamocortical fibers.
What part of the brain is REM elaborate visual imagery associated with?
PPRF (Paramedian pontine reticular formation).
What can result in a positive Babinski sign?
Being a baby, corticospinal tract damage, UMN damage.
What is the olfactory cortex’s Brodmann number?
28, 34
What are the types of herniations following brain injury?
Cingulate (cingulate gyrus slips under falx cerebri and presses on other hemisphere). Usually inconsequential. Uncal (Uncus herniates through the tentorial notch and presses midbrain). Coma/death. Tonsilar (cerebellum presses on medulla through foramen magnum). Rapidly fatal.
What neurotransmitters do propiomelanocortin give rise to?
It’s a peptide. Gives rise to endorphin, enkephalin, ACTH.
How many spinal arteries are there?
2 anterior and one posterior.
How do you treat conductive vs sensorineural hearing loss?
Conductive can be surgerized, sensorineural can be treated with a cochlear implant.
What are the types of glands in the outer ear?
Mixture of ceruminous (white) and sebaceous.
What kind of drug is capsaicin, how does it work, and what kind of pain does it treat? Also, how is it administered?
A local anaesthetic, agonist at the TRPV1 receptor. Treats nociceptive and neuropathic pain. Cream or liquid topically.
What muscle, nerve root, and nerve does the achilles/ankle jerk reflex test.
Gastrocnemius and soleus, S1, tibial n.
What sensation does the DCML pathway transmit?
Discriminative touch, mainly.
What is Kluver-Bucy syndrome?
Large bilateral amygdaloid lesions. Become placid, inappropriately sexual, agnosia, unable to associate stimuli with reward.
How does the trigeminal system work when it transmits fine touch, vibration, pressure, and proprioception?
1st cell body in the trigeminal ganglion travels via the trigeminal tract to the pons (main sensory nucleus of V or mesencephalic nucleus) and synapses. 2nd neuron crosses over in the pons and travels up the trigeminal lemniscus/trigeminal thalamic tract and synapses in the VPM. 3rd neuron synapses into the somatosensory cortex.
How does the trigeminal system work when it transmits pain?
1st cell body in the trigeminal ganglion travels down in the descending tract of V to the pons (spinal nucleus of V) and synapses. 2nd neuron crosses over in the pons and trvels up the trigeminal lemniscus/trigeminal thalamic tract and synapses in the VPM. 3rd neuron synapses into the somatosensory cortex.
Describe the CN VI palsy.
Horizontal diplopia, cannot abduct.
Where are the parasympathetic autonomic nuclei in the spine?
Intermediate zone, S2-S4.
Describe Meissner’s Corpuscles.
Superficial, rapidly adapting. Sensitive to light touch.
What is the important part of the brain in long term potentiation?
Hippocampus. Quick high frequency EPSP that keeps the signal lasting for a long time.
What is the Brodmann’s number for the primary motor cortex and where is it?
Precentral gyrus, 4.
Describe smooth pursuit.
FEF initiates ipsilateral smooth pursuit - talks to pontine nucleus which talks to flocculus of the cerebellum, which crosses to the contralateral vestibular nucleus.
Vestibular nucleus’ contralateral CN VI is excited, ipsilateral one is inhibited. In a coma, can activate the vestibular nucleus by head rotations.
What is the paleospinothalamic / spinoreticular tract?
Sends memos to the reticular formation. Integrates emotion and motivation.
What causes truncal ataxia? How do they present?
Usually lesions to the vermie/flocculonodular lobe of the cerebellum. Present with ‘drunk-like’ gait in the Tandem Gait Test.
What is an Argyll-Robertson pupil?
Affected pupil doesn’t constrict in response to light but does during accomodation.
When left to run freely, what is a person’s circadian rhythm?
25h.
What are some factors associated with motor return after a spinal cord injury?
Initial grade of impairment at time of admission, pinprick sensation at initial examination, presence/absence of early motor return, motor function at 1 month after injury.
How many semicircular canals are there?
Three.
What are the derivatives of the telencephalon?
Cerebral hemispheres, olfactory tract/bulb, basal nuclei. Also lateral ventricles.
Describe the auditory pathway.
Cochlear nucleus talks bilaterally to both superior olivary nuclei. Superior olivary nucleus talks via the lateral lemniscus to the inferior colliculus, which goes to the MGN of the thalamus, and then the primary auditory cortex.
Where is the Edinger-Westphal nucleus?
In the upper midbrain.
What is the difference between the spine and brain dura?
Brain has 2 layers, spinal cord has one.
What type of receptor is 5HT2, what does it respond to, and by what mechanism does it work and is it excitatory of inhibitory?
Metabotropic. Responds to serotonin. Increases IP3/DAG and decreases K+ conductance. Excitatory.
What kind of drug is carbamazepine, how does it work and what kind of pain does it treat?
Anticonvulsant, blocks VG Na+ channels. Treats neuropathic pain, also epilepsy, can also treat bipolar disorder (also pain of V or IX neuralgia).
What are the primary vesicles of brain embryological development and when do they develop?
4th week. Prosencephalon, Mesencephalon, Rhombencephalon.
What kind of drug is ketamine and what kind of pain does it treat?
NMDA antagonist (non-competitive), and treats neuropathic pain. At higher doses can be an anaesthesia.
A lesion to the pons/PPRF causes which way eyes?
Wrong way eyes.
What kind of hemorrhage does a rupture of the cerebral artery or vein cause?
Subarachnoid, intraparenchymal, intraventricular.
Where does the tectospinal tract originate and decussate and terminate? Also, what does it do?
Originates in superior colliculus, decussates in midbrain, terminates in cervical spinal cord laminae VI-VIII. Function unknown but thought to produce postural changes in response to visual stimuli.
Describe the Papez circuit.
Important for storage of memory. Hippocampus to mammillary bodies to anterior nucleus of the thalamus to cingulate cortex. Sometimes singulate can project back to the hippocampus.
What is the stria of bennari?
4B visual cortex.
What kind of neurons are in the basal forebrain and what does it do?
Cholinergic. Determines the value/significance of memories/events.
What is drug dependence?
Any repeated use of a drug leading to an altered physiological state that requires continued exposure to prevent withdrawal syndromes.
What are the branches of the vertebral arteries?
Anterior and posterior spinal arteries, also PICA (posterior inferior cerebellar).
What is Adie’s/Tonic pupil?
Affected pupil slow to constrict in both reflexes and slow to recover.
What modalities does CN II transmit?
SSA (vision).
How do you get quadrantanopia?
Injure the divisions of the optic tract or just the cuneus / lingual gyrus.
Describe CN IV palsy.
Vertical diplopia (improves when head tilted ‘away’, worsens with downward/nasal gaze).
What’s the difference between somatic and visceral pain?
Somatic is localized, sharp, throbbing, visceral is diffuse, gnawing, cramping.
What is the Brodmann’s number for the primary visual cortex and where is it?
Occipital lobe, 17.
What does a lesion of the optic chiasm cause?
Bitemporal hemianopia (loss of temporal visual fields).
Where is the main input of the pontocerebellum and what deep cerebellar nucleus does it work with?
Main inputs from sensory/motor cortices, works with dentate.
How does junctional transmission terminate?
Either enzymatic cleavage or diffusion away or dissipation of the transmitter via active reuptake into presynaptic neuron or active reuptake into associated structures like neuroglia.
What do Rexed’s Laminae III, IV, V do and what are they called?
Nucleus proprius. Transmit mostly non-noxious stimuli however V can also do some noxious (wide dynamic range).
Where do signals go from the fastigial nucleus?
To the vestibular nucleus of the thalamus.
What connects the organ of corti to the basal lamina?
Spiral ligament.
What type of receptor is GABAa, what does it respond to, and by what mechanism does it work and is it excitatory of inhibitory?
Metabotropic. GABA. Increases K+ conductance. Inhibitory.
How is interaural time delay processed?
By the medial superior olive in the superior olivary complex. Needs coincidental excitatory input.
What is the visual association cortex Brodmann number?
18, 19
Describe N1 of non-REM sleep.
Alpha waves to theta waves on EEG. Somnolence/drowsy sleep. Sudden nypnic jerks, hypnagogic hallucinations, loss of muscle tonie, loss of most conscious awareness of external environment.
Where is the conus medullaris?
L1/L2 in adults, L3 in children.
What does the Doll’s Eye test?
VOR (brainstem) in a patient with a coma.
What is in the anterior area of the hypothalamus?
Paraventricular and supraoptic nucleus. Regulate water balance, secrete oxytocin and vasopressin. Anterior nucleus - stimulation causes heat dissipation. SCN - circadian rhythm.
How are sweet, bitter, and imani tastes received?
They bind to a GPCR. Sweet - closes K+ channels, bitter causes Ca++ release from the ER. Both result in neurotransmitter release.
What is sleep-related hypoventilation?
Increased PaCO2, particularly when sleeping. - reduction i ventilatory response to hypoxia. Headaches in morning, associated with decreased muscle muscle tone in REM.
What is primary and secondary damage?
Primary is damage from the initial trauma, secondary is indirect result of injury such as edema that comes from it.
What is the ventromedial nucleus of the hypothalamus?
Anterior (larger in females, sexually dimorphic) and Posterior (Satiety center - leptin binds).
Describe the organ or Corti.
Highly specialized cells on basilar membrane, 1 row of inner and 3 rows of outer hair cells (have stereocilia). Covered by tentorial membrane.
Describe CN III palsy.
Down and out, hypotrophic, abducted, intorted, ptosis, dilated pupil.
What type of receptor is GABAA, what does it respond to, and by what mechanism does it work and is it excitatory of inhibitory?
Ionotropic. GABA. Increases Cl- conductance. Inhibitory.
Describe the basal ganglia direct pathway.
Cortex excites striatum, inhibits GPi, inhibits thalamus, excites cortex. Net excitation to cortex.
What is holoprosencephaly? What gene is it associated with?
Failure of the hemispheres to separate - varying severity. Associated with a SHH mutation.
What is anencephaly/craniorachischisis associated with?
B9 and maternal type I diabetes.
What are the components of the epithalamus?
Pineal gand (attached to 3rd ventricle by pineal stalk), and habernular nuclei (afferent from stria medullaris thalami, efferent to interpeduncular nuclei).
How many neurons are in sensory and motor pathways?
3 and 2.
What is the Brodmann’s number for the primary somatosensory cortex and where is it?
Postcentral gyrus, 3, 1, 2.
What are the first 2 layers of the LGN?
Magnocellular - deals with movement and contrast - parasol ganglion cells. Layer 1 from the contralateral eye, layer 2 from the ipsilateral eye.
Describe A beta fibers.
Medium, myelinated, transmit mechanoreceptor info from skin.
What is doublecortin? What do mutations in it result in?
An MT-associated protein needed for proper neuronal migration. X-linked mutation results in males with lissencephaly (LISX1) or pachygyria, in heterozygous females it causes subcortical laminar band heterotopia.
