Neuroscience - Block 2 - Part 1

davidwurbel7's version from 2016-03-05 17:25


Question Answer
Sensory signals generally not consciously perceivedGVA
Motor projects to glands, smooth and cardiac musclesGVE
The ANS neurons are myelinatedPre-Synaptic Neurons
These ANS neurons are unmyelinatedPost-Synaptic Neurons
Control originates in the hypothalamus and brain stemANS
Primary respiratory center - Inspiration center is inDorsal Medulla
Primary respiratory center - Expiration center is inVentral Medulla
Secondary respiratory center that inhibits inspiration rampingPneumotaxic Center
The primary control center for sympathetic vasomotor tone, release of NE and vasoconstrictionRVLM
Failure to control this may result in over-dilation of blood vessels. Possible neurogenic shock - Hypotension + bradycardiaVasotone
The Dorsal longitudinal fasciculus, Medial forebrain bundle and the Mammilotegmental tract are the three main pathways connecting this (and other brain structures) to the brainstem and spinal cordHypothalamus
The primary hypothalamic pathway that originates in the paraventricular nucleus. The tract is bilateral but ipsilaterally dominance Dorsal Longitudinal Fasciculus
This terminates (in part) Mesencephalic reticular formation, Pontine reticular formation, Dorsal motor nucleus of the vagus nerve, Nucleus ambiguus, Medullary raphe, Autonomic nuclei of the spinal cordDorsal Longitudinal Fasciculus
This regulates salivary and digestive secretion, lacrimal glands, and GIT smooth muscleDorsal Longitudinal Fasciculus
The primary hypothalamus input from Septal nuclei, Basal forebrain limbic structures and indirectly from the Amygdala and Hippocampus. The tract is bilateral, but ipsilaterally dominantMedial Forebrain Bundle
This tract is less prominent than either the DLF or MFB. It originates in the mammillary nucleus sends projections to broadly the same autonomic nuclei as the DLF and MFBMammillotegmental Tract
Contains 3 cervical ganglia, 12 thoracic ganglia, 4 lumbar ganglia, 4 sacral ganglia and 1 coccygeal ganglionSympathetic Chain Ganglia
Preganglionic neurons of this only leave the spinal cord between T1 and L2Sympathetic Chain Ganglia
The other name for the Sympathetic Chain Ganglia is thisParavertebral Ganglia
These can leave the sympathetic chain in four ways - Spinal nerves, Cephalic periarterial nerves, Sympathetic nerves, Splanchnic nervesSympathetic Postganglionic Neurons
Axons enter the sympathetic ganglia via theWhite Rami
Spinal nerve exits via theGray Rami
Preganglionic neurons enter the sympathetic chain. Ascend to the superior cervical ganglion and synapse. The postganglionic neurons leave as this traveling with the carotid arteryCephalic Periarterial Nerves
Serve visceral effectors in the skin of the face and head - Sweat glands, Smooth muscle of blood vessel, Arrector piliCephalic Periarterial Nerves
Preganglionic neurons enter sympathetic chain at cervical levels. Postganglionic neurons leave the sympathetic chain to formSympathetic Nerve
Innervates the heart and lungsSympathetic Nerve
Preganglionic axons pass through the sympathetic chain, without synapsing and instead they synapse in collateral gangliaSplanchnic Nerve
Innervated by T5 to T9. Third order neurons innervate the Stomach, Spleen, Liver, Kidneys, Small intestinesGreater splanchnic nerve
Innervated by T-10 to T-12. Third order neurons innervate the blood vessels of small intestine and proximal colonLesser splanchnic nerve
Innervated by L-1 and L4. Third order neurons innervate smooth muscle/glands of the pelvic viscera and hindgutLumbar Splanchnic Nerve
These are any ganglia not in the sympathetic chain which include Celiac, Aorticorenal and Superior and inferior mesenteric gangliaCollateral ganglia
These are stimulated by sympathetic preganglionic adrenal neurons to release epinephrine, norepinephrine and small amount of dopamineChromaffin Cells
These fibers originate in the brain stem and sacral spinal cordParasympathetic Preganglionic Fibers
Synapse in ganglia close to (or within) the target organs. Preganglionic fibers are long and postganglionic fibers are short.Parasympathetic System
Pupil constriction via E-W nucleus and accommodationCiliary Ganglia
Lacrimal glands and nasal mucosaPterygopalatine Ganglia
Sublingual salivary glandsSubmandibular Ganglia
Parotid salivary glandsOtic Ganglia
Carries nearly 80% of the total craniosacral flow to heart, lungs, liver, stomach, GIT,etc Vagus Nerve (CN X)
These neurons usually synapse with 4-5 postsynaptic neurons all of which supply a single visceral effectorParasympathetic Presynaptic Neurons
These originate from the cranial nerves III, VII, IX and XCranial Preganglionic Neurons
All ANS preganglionic neurons release ACh which bind to these receptorsNicotinic (N[N]) Receptors
All ANS postganglionic parasympathetic neurons release this neurotransmitterACh
These neurons may release Epinephrine, Norepinephrine, Dopamine, AChPostganglionic Sympathetic Neurons
Plexus involved in GIT motilityMyenteric Plexus
Plexus involved in controlling secretions of the GI tractSubmucosal Plexus
ENS stimulation from this increases secretion and activityParasympathetic
ENS stimulation decreases secretions and activitySympathetic
Fibers of right vagus nerve innervate this in the heartSA node
Fibers of left vagus nerve lead to theAV node


Question Answer
Misalignment of the eyeStrabissmus
Cranial nerve that exits the brainstem posteriorly and innervates the opposite eyeTrochlear Nerve
The left trochlear nerve's nucleus is theRight Trochlear Nucleus
The right trochlear nerve's nucleus is theLeft Trochlear Nucleus
Connect CN III, IV, VI and vestibular VIIIMedial Longitudinal Fasciculus (MLF)
Allows for coordinated eye movementMedial Longitudinal Fasciculus (MLF)
Connects the cortex to cranial nervesCorticobulbar Tract
Connects the cortex to the cerebellumFrontopontinecerebellar Tract
Cross section of the midbrain containing the CN III and the red nucleusLevel of the Superior Colliculus
Cross section of the midbrain containing the CN IV and without the red nucleusLevel of the Inferior Colliculus
This is not part of the midbrain. Part of the thalamus but is seen in the a cross section in the superior colliculusMedial Geniculate N. (MGN) and Lateral Geniculate N. (LGN)
This is a relay for auditory but is not actually part of the midbrainMedial Geniculate Nucleus
This is a relay for visual but is not actually part of the midbrainLateral Geniculate Nucleus
Ascending auditory signalsLateral Lemniscus
Damage to this usually causes no symptoms but may cause trouble localizing soundLateral Lemniscus
Comprises the lateral and anterior spinothalamic tracts, and spinotectal tract. Ie. As these ascending sensory tracts leave the spinal cord, they come together to form thisSpinal Lemniscus
Dorsal column fiber tract is called this when it passes through the brainstemMedial Lemniscus
The name for the ascending axons of the trigeminal nerve (going to thalamus)Trigeminal Lemniscus
This UMN control of cranial nervesCorticobulbar Tract
Innervates most CN’s bilaterally. It does innervate a few things contralaterally only (like CST) thus there are a few clinical findingsCorticobulbar Tract
Pathway by which cerebellum influences coordination of skilled motor movementsRubrospinal Tract
Connects CN’s III, IV and VI for conjugate eye movements as well as the vestibular component of VIIIMedial Longitudinal Fasciculus (MLF)
Determines levels of wakefulness, amongst other thingsReticular Formation
Surrounds the cerebral aqueduct. Important component of pain suppression systemsPeriaqueductal Gray (PAG)
Supplies the midbrain with bloodPosterior Cerebral Artery
Supplies the medulla with bloodVertebral Arteries
Supplies the pons with bloodBasilar Artery


Question Answer
Cranial nerve nuclei for V, VI, VII, and VIII are found herePons
Last part of the cerebral aquaduct. Transverse fibers. Mesencephalic nucleus is part of CN V. Medial longitudinal fasciculus connects CN’s III, IV, VI and VIII. Superior cerebellar peduncle connects midbrain with cerebellumRostral Pons
The 4th ventricle. Transverse fibers. Middle cerebellar peduncle connecting the pons with cerebellum. Motor nucleus of CN V only visible hereMid Pons
The motor nucleus of CN V is only visible in this section. Middle cerebellar peduncle is prominent with transverse fibersMid Pons
The mesencephalon nucleus of CN V is found in this sectionRostral Pons
Contains CN VI, CN VII and VIII. 4th ventricle. Trapezoid body is part of the ascending auditory pathway. Inferior cerebellar peduncleCaudal Pons
Formed by the motor axons of CN VII; they ‘wrap’ around the nuclei of CN VI before exiting the ponsFacial Colliculus
First branch off of the basilar arteryParamedian Artery
Performs the same function in the caudal pons as the circumflex arteriesAnterior Inferior Cerebellar Artery (AICA)
Supplies the medial portion of ponsParamedian Artery
Supplies the medial lateral portion of the ponsShort Circumflex Branch of the Basilar Artery
Supplies the lateral portion of the ponsLong Circumflex Branch of the Basilar Artery
Supplies the superior portion of the rostral ponsSuperior Cerebellar Artery
Tract from the cortex to the pontine nucluci which cross and then talk to the cerebellumCorticopontocerebellar Tract
Sensory nucleus of CN V found in the ponsMesoencepthic Nucleus


Question Answer
Cranial nuclei for IX, X, XI and XII. The pyramids, and pyramidal decussation. Olivary nuclei. Aspects of other cranial nerves, the nucleus ambiguus, and nucleus solitarius. Reticular formation, ascending and descending tractsMedulla
This CN exits between the Olive and the pyramidHypoglossal Nerve
These CN exit behind the OliveCN 9, 10 and 11
Send fibers crossing to cerebellum via inferior cerebellar peduncle, and are involved with the cerebellum in the coordination of voluntary movement. They also connect the two cerebellar hemispheres, which makes sense since movements on both sides of the body need to be coordinatedOlivary Nuclei
The cell bodies for the motor component of CN IX, X, XI are contained in this structureNucleus Ambiguous
The second order neuron cell bodies for CN VII, IX and X (taste sensory) are contained in this structureNucleus Solitarius
Corticobalbar talks to the contralateral CN VII and CN XII cause the tongue to do thisDeviate Away from the Lesion
CN XII damage will cause the tongue to do thisDeviate Toward the Lesion

Blood Supply

Question Answer
Small perivascular extensions of the SAS that surround the blood vessels as they penetrate the brainVirchow-Robin space(s)
Provides interconnection between the two carotid arteries and the two vertebral arteriesCircle of Willis
Artery from internal carotid (ICA) to anterior communicatingAnterior Cerebral Artery (ACA) A1
Artery after anterior communicating arteryAnterior Cerebral Artery (ACA) A2
Medial surface of the cerebral hemispheres which would include ‘leg’ area of pre- and post-central gyriAnterior Cerebral Artery
Very big striate artery, supplies head of caudate, anterior part of putamen and globus pallidus, anterior limb of internal capsuleRecurrent Artery of Heubner
ACA A2 gives rise to this medial striate artery, which supply some of the deep grey structuresRecurrent Artery of Heubner
Artery from Internal Carotid Artery to insulaMiddle Cerebral Artery (MCA) M1
Supplies Dorsal head, and whole body, of caudate nucleus. Parts of lentiform nucleus (globus pallidus and putamen). Internal capsule (part of anterior limb along with ACA, the genu, and posterior limb along with anterior choroidal)Lateral Striate Branches Middle Cerebral Artery (MCA) M1
Supply lateral surface of hemispheresMiddle Cerebral Artery (MCA) M2 & M3
Branches into Central retinal artery. Externalizes to supply - Frontal area of scalp, Ethmoid and frontal sinuses, Dorsum of the nose. Travels with optic nerveOpthalmic Artery
Supplies Choroid plexus of inferior horn of lateral ventricles, third ventricle, amygdala, hippocampal formation, posterior limb of internal capsule, LGN of thalamus, tail of the caudate. And maybe a little midbrainAnterior Choroidal Artery
Supplies blood to posterior 1/3 of spinal cordPosterior Spinal Artery
Supplies blood to anterior 2/3 of spinal cord. This single artery arises from both vertebral arteriesAnterior Spinal Artery
Supplies blood to inferior vermis, central nuclei of cerebellum, inferior side of cerebellar hemispheres. Also medulla, and choroid plexus of the 4th ventriclePosterior Inferior Cerebellar Artery (PICA)
Travels with VII and VIII to innervate the inner ear. Note in picture that it branches off basilar, but mostly branches off AICA (80-85% of the time)Labyrinthine Artery
Supply blood to the pons. Paramedian pontine arteries. Short circumferential arteries. Long circumferential arteries, which includes the Anterior Inferior Cerebellar Artery (AICA)Pontine Arteries
Supply blood to the superior surface of cerebellum, pons, and pineal glandSuperior Cerebellar Artery
Supply inferolateral, and medial, surface of temporal lobe (including hippocampus), and medial/lateral surfaces of occipital lobeCortical Branches Posterior Cerebral Artery
Supply internal structures, such as thalamus, midbrain, geniculate bodies, etc.Central Branches Posterior Cerebral Artery
Supplies choroid plexus in lateral and third ventriclesChoroidal Branch Posterior Cerebral Artery
Supplies the geniculate bodies of the thalamus, ventral lateral and ventral posterior nucleiThalamogeniculate Branch Posterior Cerebral Artery
Supplies Thalamus and parts of hypothalamus, parts of midbrainThalamoperforate Branch Posterior Cerebral Artery
Supplies primary visual area (Brodman's area 17)Calcarine Branch Posterior Cerebral Artery
Supplies midbrain (Colliculi)Quadrigeminal Branch Posterior Cerebral Artery
Supplies midbrainMedial Posterior Choroidal Branch Posterior Cerebral Artery
Ascend upwards over lateral surface of hemispheres. Empty into superior sagittal sinusSuperior Cerebral Vein
Drains lateral surface of cerebral hemispheres. Passes through lateral sulcus and empties into cavernous sinusSuperficial Middle Cerebral Vein
Along with anterior cerebral and striate veins, forms the basal vein. Drains insulaDeep Middle Cerebral Vein
Empties into the straight sinus. It is formed from the union of the thalamostriate, and choroid veinsGreat Cerebral Vein
Supplies the pineal gland with bloodSuperior Cerebellar Artery