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What part of the brain do each of the cranial nerves originate from? - ANSWER - Telencephalon: CNI
- Diencephalon: CNII
- Mesencephalon: CNIII, CNIV
- Metencephalon: CNV, CNVI, CNVII
- Myelencephalon: CNVIII, CNIX, CNX, CNXI, CNXII
Describe GSA Fibers. Which Cranial nerves fall under this category? - ANSWER Typical touch/pain sensation CNV, CNVII, CNIX, CNX
Describe SSA Fibers. Which Cranial nerves fall under this category? - ANSWER Vision and vestibular/auditory sensation CNII, CNVIII
Describe GVA Fibers. Which Cranial nerves fall under this category? - ANSWER Sensory info from viscera and blood vessel walls CNIX, CNX
Describe SVA Fibers. Which Cranial nerves fall under this category? - ANSWER Smell and taste CNI, CNVII, CNIX, CNX
Describe SVE Fibers. Which Cranial nerves fall under this category? - ANSWER Control of muscles derived from brachial arches ie muscles of mastication, facial expression, neck muscles, pharynx/larynx CNV3, CNVII, CNIX, CNX
Describe GVE Fibers. Which Cranial nerves fall under this category? - ANSWER Autonomic Nervous System CNIII, CNVII, CNIX, CNX
Describe GSE Fibers. Which Cranial nerves fall under this category? - ANSWER Other skeletal muscles CNIII, CNIV, CNVI, CNXI, CNXII
Which CN are derived from the brachial arches and what muscles do they innervate - ANSWER Arch 1: V3, muscles of mastication Arch 2: VII, muscles of facial expression Arch 3: IX, pharyngeal muscles Arch 4 & 6: X, pharyngeal and laryngeal muscles
Which sensory ganglia are associated with the cranial nerves? - ANSWER Trigeminal (V) Geniculate (VII) Spiral (VIII) Vestibular (VIII)
Which autonomic ganglia are associated with the cranial nerves - ANSWER Ciliary (III) Pterygopalatine (VII) Submandibular (VII) Otic (IX)
Draw out the pathway of CNI. Describe its features. - ANSWER
Draw out the pathway of CNII. Describe its features. - ANSWER
can agree that lacrimal gland innervation comes through the pterygopalatine ganglion and to the zygomatic nerve In the classical pathway it then jumps to the lacrimal nerve before hitting the lacrimal gland In the alternate pathway it goes straight from the zygomatic to the lacrimal gland
Functional Components of the Cranial Nerves - ANSWER CN I - SVA CN II - SSA CN III - GSE, GVE CN IV - GSE CN V - SVE, GSA CN VI - GSE CN VII - SVA, GVE, SVE, GSA CN VIII - SSA CN IX - SVA, GVE, GVA, SVE, GSA CN X - SVA, GVE, GVA, SVE, GSA CN XI - GSE, SVE? CN XII - GSE
What are the major regions of the brain - ANSWER Cerebrum, Diencephalon, Brainstem, Cerebellum
Briefly describe CNS embryonic development - ANSWER CNS starts off as a neural tube and the cranial end develops to form three primary brain ventricles: Forebrain (Proencephalon), Midbrain (Mesencephalon), Hindbrain (Rhombencephalon) The proencephalon and rhombencephalon further divide into secondary brain ventricles, the telencephalon/diencephalon and metencephalon/myelencephalon respectively
Describe the locations of white and grey matter - ANSWER In the cerebrum/cerebellum
grey matter is superficial and white matter is deep In the brainstem/spinal cord white matter is superficial and grey matter is deep
Describe each of the three meninges - ANSWER Dura mater - outermost, lies against the cranium/spinal canal, very tough, provides protection, forms the dural deflections and dural sinus system, inner meningeal layer and outer periosteal layer Arachnoid mater - web like structure of collagen and elastic fibers that blood vessels and CSF can pass through, subarachnoid space Pia mater - thin delicate layer that lies right against the brain
Describe the dural deflections - ANSWER Falx cerebri - divides right and left cerebral hemispheres Falx cerebelli - divides right and left cerebellar hemispheres Tentorium cerebelli - divides cerebellum from cerebrum (occipital)
Describe the dural sinus system including pathway of blood flow - ANSWER Week 8 Review
Describe the ventricles of the brain - ANSWER Lateral - one in either hemisphere, crescent shaped, connected to the 3rd by the interventricular foramen, choroid plexus 3rd - along midline between left and right sides of the thalamus, infero-posterior to lateral ventricles, connected to the 4th by the cerebral aqueduct 4th - along midline in brainstem, between cerebellum and pons/medulla, drain into central spinal canal and subarachnoid space by 2 lateral and 1 medial aperture All lined by ependymal cells that secrete CSF
Discuss cerebral localization - ANSWER Most fibers in the brain decussate, functions like spatial awareness, facial recognition, creativity, and auditory understanding are found on the non-dominant side while functions like language and speech perception, handedness are found on the dominant hemisphere
Discuss Brodmann 1, 2, and 3 - ANSWER Primary somatosensory cortex, found on the postcentral gyrus, granular heterotypic
Discuss Brodmann 40 - ANSWER Secondary sensory area, pain and tactile discrimination, just above lateral fissure
Discuss Brodmann 5 and 7 - ANSWER Sensory association areas, posterior parietal, integrates sensory info, output may go to limbic system
Discuss Brodmann 17 - ANSWER Primary visual cortex, found in the occipital right near the calcarine fissure, receives info from LGN and processes it, granular heterotypic
Discuss Brodmann 18 and 19 - ANSWER Secondary visual areas, receive image info from 17 and turn it into meaningful what/where info
Discuss other areas of interest related to vision - ANSWER Frontal eye fields in the frontal lobe precentral and middle central gyrus are important for pursuits
Discuss the brain areas related to audition - ANSWER 41 and 42 are the primary auditory cortex in the superior temporal gyrus, receive info from MGN and may also be an eye field, 22 (Wernicke's) does interpretation and association
Discuss the cortical association areas - ANSWER Prefrontal cortex: 9, 10, 11, 12 Anterior Temporal: stores sensory experiences, object recall Posterior Temporal: touch, pressure, proprioception
Discuss the Wernicke-Broca locus - ANSWER Wernicke's is found in the superior temporal gyrus of the dominant hemisphere, speech sensory, inability to understand language Broca: speech motor found in the dominant inferior frontal gyrus
Describe the basal nuclei - ANSWER The basal nuclei are found deep within the brain on either side of the 3rd ventricle, wrapping around the thalamus Includes the caudate nucleus, the lentiform nucleus, and the amygdaloid body Functions in posture, mood, emotion, and fine tuning motor signals Information flows from Brodmann 4/6 -> caudate -> putamen ->globus pallidus -> cortex -> execution
Describe the caudate nucleus - ANSWER C shaped, connects to the lentiform putamen at one end and the amygdaloid body at the other, wraps superiorly around the thalamus, split into head/body/tail regions with head and body in contact with the thalamus
Describe the lentiform nucleus - ANSWER Sits anterior to the thalamus, split into putamen medially and globus pallidus laterally Putamen meets the caudate at the nucleus accumbens, grey matter connects the two posterior to this
Describe the cerebral white matter tracts - ANSWER Association: connects different point within the same hemisphere Commissural: connects the two hemispheres (corpus callosum, anterior commissure, posterior commissure, habenular commissure) Projection: connects the cerebrum to the brainstem/spinal cord (internal capsule, external capsule, corona radiata)
What structures are part of the diencephalon? - ANSWER Epithalamus Subthalamus Thalamus Hypothalamus
What are the boundaries of the diencephalon? - ANSWER Superior: floor of lateral ventricles
Pupil Dilation/Constriction and Accommodation Physical Manifestation of Emotion Hormone Regulation
What is the purpose of the limbic system? - ANSWER Emotion and Motivation related activity Short term to Long term memory
Where is the limbic system? - ANSWER The limbic system is deep in the cerebrum and wraps around the basal nuclei and the diencephalon It is a functional brain system, meaning it crosses between more than one brain area, in this case the cerebrum and midbrain
What are the components of the limbic system? - ANSWER Hippocampal Gyri Hippocampus Fornix Amygdaloid Bodies Cingulate Cortex Thalamus/Epithalamus Olfactory Pathway Mammillary Bodies
Describe the Cingulate Cortex - ANSWER C shaped, lies superior to corpus callosum and lateral to the longitudinal fissure, merges with the parahippocampal gyrus, input from the Papez circuit, output to the parahippocampal gyrus Functions in emotion, pain, motor initiation, and emotion driven autonomic changes
Describe the hippocampus - ANSWER Lies superior to the parahippocampal gyrus of the deep temporal lobe, input from parahippocampal gyrus (entorhinal cortex), output to the fornix via fimbria
Functions in memory storage and converting short term to long term
Describe the fornix - ANSWER Body runs between the corpus callosum and thalamus, crura anterior, columns posterior, runs from hippocampus to mammillary bodies
Describe the mammillary bodies - ANSWER Lie on the inferior surface of the hypothalamus, input from fornix, output to anterior thalamic nuclei
Describe the Papez circuit - ANSWER Thalamus -> Cingulate Cortex -> Parahippocampal Gyrus -> HIppocampus -> Fornix -> Mammillary Bodies -> Anterior Thalamic Nuclei Emotional control via autonomic/endocrine functions Amygdala may provide input at the Mammillary Bodies
Describe the amygdala - ANSWER Lies at the tail end of the caudate nucleus, output to the hypothalamus and brainstem Fear, short term to long term memory
Which cranial nerve nuclei are found in the brainstem and where? - ANSWER CN III - midbrain/mesencephalon CN IV - midbrain/mesencephalon CN V - pons/metencephalon CN VI - pons/metencephalon CN VII - pons/metencephalon CN VIII - medulla/myelencephalon CN IX - medulla/myelencephalon CN X - medulla/myelencephalon CN XI - medulla/myelencephalon CN XII - medulla/myelencephalon
Describe the internal anatomy of the midbrain - ANSWER Cerebral aqueduct Tectum
Describe the CN III nuclei - ANSWER Primary motor nuclei for IR, MR, SR, IO, Levator, all ipsilateral except SR Edinger-Westphal is autonomic control of accommodation and pupil responses, ipsilateral Pupillary Light Pathway: optic tract -> pretectal nucleus -> Edinger-Westphal (bilateral) -> Eyes Near Pupillary Response Pathway: primary visual cortex -> frontal eye fields -> Edinger-Westphal -> convergence
Describe the surface anatomy of the pons - ANSWER Ventral to cerebellum, caudal to midbrain, rostral to medulla Ventral/Lateral Surfaces: Transverse fibers cross midline basilar groove which houses the basilar artery, middle cerebellar peduncles lie laterally and connect brainstem to cerebellum Dorsal Surface: covered by cerebellum, middle cerebellar peduncles mark the dorsal to lateral transition, median sulcus/medial eminences - facial colliculi are the inferior ends of the medial eminences and are the motor fibers from CN VII, fourth ventricle
Describe the internal anatomy of the pons - ANSWER Trapezoid body - hearing, receives input form CN VIII and sends output to MGN and inferior colliculi Ventral to the trapezoid body is the basal part Dorsal to the trapezoid body is the tegmentum containing the nuclei for CN IV, CN V, CN VI, CN VII, and the superior portion of CN VIII nuclei
Describe the surface anatomy of the medulla oblongata - ANSWER Ventral and Lateral Surfaces: Pyramids are divided by anterior median fissure carrying fibers of the corticospinal pathway (pyramid fibers decussate in caudal medulla), Olives are lateral to pyramids and house motor coordination and hearing Dorsal Surface: 4th ventricle floor, vagal and hypoglossal triangles, bound by inferior cerebellar peduncles, Posterior median sulcus separates gracile tubercles, the cuneate
tubercles are lateral to the superior portions of the gracile tubercles
Describe the internal anatomy of the medulla oblongata - ANSWER Nucleus Ambiguus: IX, X, XI control the throat muscles Solitary Tract Nucleus: VII, IX, X visceral sensation and taste Dorsal Nucleus: X parasympathetic vagus functions throughout the body
Describe the anatomy of a neuron - ANSWER Dendrites receive signals and transmit them to the soma The soma is the cell body that contains the nucleus and other organelles Axons transmit signals away from the soma and are the pathway for both anterograde and retrograde transport Terminal buttons are the site of synapse
What are the types of neuron by structure? - ANSWER Multipolar - motor and integration, most common in CNS, lots of dendrites Bipolar - special sensory, one dendrite and one axon Unipolar/Psuedounipolar - most common in PNS, sensory, dendrite and axon share a process off of the soma
What are the different types of glial cells and their functions? - ANSWER Astrocytes - main CNS metabolic and structural support cell, contribute to BBB, Vaso modulation, promote myelination, may connect to other nerves or blood vessels at any nonterminal point Ependymal Cells - produce CSF, line the ventricles and the central canal, typically ciliated and form tight junctions, anchor to astrocytes, absorptive functions Microglia - immune functions Oligodendrocytes - CNS myelination (important for BBB), able to wrap multiple axons
Briefly describe myelination - ANSWER Oligodendrocytes in the CNS area able to wrap multiple axons at once while keeping the cell body separate, Schwann cells in the PNS
Discuss sympathetic and parasympathetic functions of the iris, ciliary body, sweat glands, salivary glands, heart, lungs/GI, peripheral blood vessels - ANSWER Iris: dilation constriction Ciliary Body: accomm relax stimulate accom Salivary Glands: decreased increased Sweat Glands: increased NA Heart: tachycardia bradycardia Lungs/GI: inhibition stimulation Peripheral BV: constriction NA
Discuss the Enteric Nervous System - ANSWER Regulates motility, secretion, blood flow, and absorption in the GI tract Submucosal plexus (inner) and myenteric plexus (outer) Pretty much takes care of itself
List the fiber types of the cranial nerves - ANSWER CN I - SVA CN II - SSA CN III - GVE, GSE CN IV - GSE CN V - GSA, SVE CN VI - GSE CN VII - GSA, SVA, GVE, SVE CN VIII - SSA CN IX - GSA, GVA, SVA, GVE, SVE CN X - GSA, GVA, SVA, GVE, SVE CN XI - SVE, GSE CN XII - GSE
Describe the external anatomy of the spinal cord - ANSWER Enlargements in the cervical and lumbar regions because of the volume of information leaving/entering in those areas Cauda equina, conus medullaris, filum terminale, vertebral canal, meninges Epidural space is a real space filled with adipose in the spine as opposed to a potential space in the cranium, pia mater forms the filum terminale
Describe the internal anatomy of the spinal cord - ANSWER Grey matter is internal and has dorsal/ventral/lateral horns and a grey commissure
- dorsal horn = sensory and interneuron nuclei, ventral = motor, lateral = autonomic
- central canal within grey commissure is lined be ependymal cells White matter contains nerve tracts divided into anterior, posterior, and lateral columns/funiculus, anterior white commissure, funiculi are divided into fasciculi
Discuss interneurons and spinal reflexes - ANSWER Very short neurons that are found in the grey matter, info doesn't have to go all the way to the brain, provides a survival advantage Stretch, Golgi Tendon Organ, Withdrawal reflex
Give an overview of afferent tracts - ANSWER Three neuron chain Primary: from PNS receptor to CNS with soma in sensory ganglia (dorsal root ganglia, trigeminal, geniculate) Secondary: entirely within the CNS, soma in spinal cord or brainstem Tertiary: from thalamus to cortex, soma in thalamic nuclei Lower spinal level fibers are carried more medially, higher spinal level fibers are carried more laterally Somatotopic - tracts are arranged according to origin site
Describe the medial lemiscal pathway - ANSWER First order neuron: collects sensory info from sckin mechanoreceptors, neuromuscular spindles, Golgi Tendon Organs; info from upper limbs/trunk ascend in fasciculus cuneatus and synapse in cuneate nucleus in cuneate tubercle; info from lower limbs/trunk ascend in fasciculus gracilis and
Discuss the central autonomic pathways - ANSWER Descend beside intermediate grey matter, give rise to preganglionic fibers from lateral horns
Describe the regions of the reticular formation - ANSWER Median Paramedian - parapontine RF is responsible for initiating lateral eye movements, mostly efferent Lateral - mainly afferent, receives info from all sensory pathways, reticular activating system
Explain how the reticular formation affects eye movements - ANSWER Parapontine Reticular Formation
What are the functions of the reticular formation? - ANSWER Pattern generators: conjugate eye movements, rhythmic chewing motion, swallowing, vomiting, sneezing, coughing, yawning, locomotion patterns Higher level bladder control Preganglionic parasympathetic fibers to CN VII and IX Cardiovascular control Respiratory control Sleeping and wakefulness Sensory modulation
Describe the external anatomy of the cerebellum - ANSWER Left and right hemispheres join at vermis 3 lobes: anterior, middle, flocculonodular 2 fissures: primary and posterolateral Folia similar to gyri, midbrain superior cerebellar peduncle, pontine middle cerebellar peduncel, medullary inferior cerebellar peduncle
Describe the functional organization of the cerebellum - ANSWER Flocculoarnodal lobe - maintenance of posture and balance (vestibulocerebellum) Anterior lobe/portion of vermis/medial portion of meddle lobe - reulation of muscle tone (spinocerebellum) Lateral portion of middle lobe - skilled movements (pontocerebellum)
Describe the cell layers of the cerebellum - ANSWER Molecular - outermost, inhibitory Purkinje - inhibitory Granular - innermost, excitatory; golgi cells are inhibitory
Describe input to the cerebellum - ANSWER Climbing fibers - originate and the inferior olivary complex, synapse onto purkinje cells in the molecular layer, excitatory Mossy fibers - originate anywhere else, synaptic complexes with granular cells called cerebellar glomeruli in the granular layer, excitatory, granule cells synapse with Purkinje cells, local inhibitory functions
Describe output from the cerebellum - ANSWER Purkinje cell axons via cerebellar nuclei, to red nucleus of midbrain and vestibular nuclei and reticular formation
