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neurscience basics
jeffs 1st powerpoint
| Question | Answer |
|---|---|
| what two systems make up the nervous system? | central nervous system and peripheral nervous system |
| where is the CNS located? | inside bony case |
| where is the PNS located? | outside the bony case |
| what makes up the CNS? | cerebrum, cerebellum, brain stem, and spinal cord. |
| what is the basic functional unit of the CNS? | neuron |
| what two parts make up the neuron? | axon and cell body |
| is the axon white matter or gray matter? | white matter (b/c of myelin) |
| is the cell body white matter or gray matter? | gray matter |
| where is the grey matter located in the CNS? | cortex, nucleus and horn |
| where is the grey matter located in the PNS? | ganglia |
| where is the white matter located in the CNS? | tracks, columns, lemniscus, AND fasiculus |
| where is white matter located in the PNS? | peripheral nerves and plexus |
| is afferent a sensory or motor nerve? | sensory |
| is efferent a sensory or motor nerve? | motor |
| does afferent signal go toward brain or away from brain? | signal goes toward brain |
| does efferent signal go toward brain or away from brain> | signal goes away from brain |
| what divides the cortex into lobes? | the central sulcus and lateral fissure |
| name the lobes of the cortex. | frontal, parietal, occipital, temporal |
| frontal lobe | cognition and motor,thought,imaginations, conceptualization(making things happn) |
| parietal lobe | sensation,recognition, organizing. mostly about recognizing sensory stimulus |
| occipital lobe | vision |
| temporal lobe | hearing,recognition of sounds, making sense of sounds |
| what is a gyrus? | "Bumps" on the brains cortex |
| what is a sulcus? | "Valleys" on brains cortex |
| what is a soma? | cell body |
| what things do the nucleus contain? | dna, mitochondria to make energy |
| what are dendrites? | projections off of cell body |
| what is an axon? | long projection off of cell body |
| is the axon myelinated? | yes |
| what are the nodes inside of axon? | nodes or rambiere? |
| a nerve impulse always goes one way..True of False? | true |
| which ways can nerve impulses go? | they can go from terminals to nucleus or from cell body to axon |
| how do we know which way the nerve impulse is going to go? | depends on where the nerve cell is located . thats what determines which way the nerve impulse will go |
| what are ganglians? | places where gray matter can exists outside the CNS |
| can white matter be outside and inside the CNS? | yes |
| what is a fasiculus, column, tract,and lemniscus? | a collection of white matter within CNS |
| whats the purpose of a commissural? | connect centers within the brain and spinal cord. |
| what is the largest collection of commissural fibers in the CNS? | corpus collossum |
| what is a plexus? | collection of peripheral nerves |
| whats some other words for nerve cell? | neurons or glia |
| what are glia cells? | specialized nerve cells tht support and function |
| what are the 3 types of glia cells? | astrocyte, schwann, and oligodendrocytes |
| whats the purpose of astrocytes? | bind to different places and form a supportive network around the nerve cell. they also help to collect trash and debris and unused neurons. |
| where are the astrocytes located? | in CNS and PNS |
| what are schwann cells? | cells tht make myelin |
| where are schwann cells found? | only in PNS |
| what are oligodendrocytes? | they also make myelin |
| where are oligodendrocytes located? | in CNS |
| what happens when a nerve is stimulated? | a chemical or electrical response |
| when is a stimulated nerve going to have a chemical response? | whens its in the outside space around he neuron |
| when is a stimulated nerve going to have an electrical response? | when the components of the nerve cell itself is touching |
| can a nerve impulse be chemical and electrical? | yes |
| what is a synapse? | any type of space around nerve cell. known for what they r connecting EX:axodendritic synapse |
| how long are axons? | can be up to feet!! |
| how many nerves does the corticospinal tract have? | 2 |
| the anterior horn cell has gray matter located in the horn...True or false?? | true |
| where is the best place to get a muscle contraction?? | at the motor unit in the proximal 1/3 of the mm belly |
| is gray matter always the axon?? true or false? | FALSE..gray matter is always the cell body of the nerve |
| is white matter always the axon? tru or false? | TRUE |
| what is the purpose of gyri or gyrus? | increase surface area of the brain and gives us more storage capacity |
| what are sulci or sulcus? | fissures or grooves tht divide the brain into lobes |
| whats the purpose central sulcus? | divides the frontal lobe from the parietal lobe |
| where is the precentral gyrus located? | just before the central sulcus |
| what happens in the precentral gyrus? | motor functions |
| whats another term for precentral gyrus | motor cortex |
| what is a cortex? | gray matter in the CNS |
| where is the upper motor neuron cell body located/ | in the precentral gyrus(motor cortex) |
| where is the lower motor neuron cell body located? | anterior horn of the spinal cord |
| where is the post central gyrus located? | posterior to the central sulcus |
| where does the post central gyrus start? | parietal lobe |
| what lobe is the sensory cortex located? | parietal lobe. |
| where does the cell body of the 3rd order neuron lie? | in the post central lobe(sensory cortex) |
| what do the lateral fissures seperate? | the frontal and parietal lobe from the temporal lobe |
| what do we use the cerebellum for? | coordination and balance, and regulation of muscle tone |
| how many hemispheres do the cerebellum have? | 2...left and right brain |
| anything with the word "thalmus" is located where? | midbrain |
| whats another term for midbrain | diencephalon |
| where are most of the nuclei located? | pons and medulla |
| what are interneurons? | neurons tht connect only with other neurons |
| whats the purpose of myelin sheaths? | surround and insulate axons in the nervous system and aid in the transmission of electrical signals |
| what does the somatosensory system do? | conveys information from the skin and musculoskeletal system to areas of the brain. |
| what does the autonomic system do? | provides bidirectional communication between the brain and smooth muscle, cardiac mm, and gland cells. |
| what does the somatic motor system do? | transmits information from the brain to skeletal muscles |
| what are the 4 regions tht make up the nervous system.? | peripheral, spinal, brainstem and cerebellar, and cerebral regions |
| peripheral nerves, median, ulnar, sciatic, and cranial nerves are all groups of axons...true or false | TRUE |
| four continuous cavities within the brain tht is filled with cerebrospinal fluid is known as..?? | ventricles |
| how is the blood supply of the brain delivered? | delivered by the internal carotid and vertebral arteries |
| what does the somatic nervous system connecct with? | cutaneous and muskulocutaneous structures |
| what does the autonomic nervous system connect with? | viscera |
| areas of the CNS tht contain primarily neuron cell bodies are..?? | gray matter |
| what are groups of cell bodies(gray matter) in the peripherl nervous system called? | ganglia |
| what is gray matter on the surface of the brain called? | cortex |
| are afferent and efferent nerves within a peripheral nerve? | yes |
| what are some peripheral components of the somatic nervous system? | axons, sensory nerve endings, and glial cearlls |
| what are some peripheral components of the autonomic nervous system? | entire neurons, sensory endings, synapses, ganglia and glia |
| where does the spinal cord start and end? | starts in foramen magnum and goes to the level of the 1st lumbar vertebrae. |
| how many segments does the spinal cord have? | 31 segments with a pair of spinal nerves arising from each segment. |
| how are the spinal nerves connected to the spinal cord? | by a dorsal root and a ventral root |
| what does the dorsal root ganglian contain? | cell bodies of sensory neurons |
| what does the union of the dorsal and ventral root form? | spinal nerve |
| what are the 2 main functions of the spinal cord? | to convey info btwn neurons connected to peripheral structures and the brain and to process information |
| what is a function of the brainstem? | to convey info btwn the berebrum and the spinal cord, integrate info and regulate vital functions(heart rate, respiration, temp) |
| name the 4 structures tht the diencephalon consists of. | thalamus, hypothalamus, epithalamus, subthalamus |
| what is the thalamus? | large collection of nuclei in the center of the cerebrum |
| what does the epithalamus consist of? | primarily of the pineal gland |
| what do the thalamic nuclei do? | relay info to the cerebral cortex, process emotional and some memory information, integrate different types of sensation. |
| what is the purpose of the hypothalamus? | maintains body temp, metabolic rate and chemical composition of tissues and fluids within an optimal functional range |
| what does the longitudinal fissure divide? | the two cerebral hemispheres. |
| list the 6 lobes tht divide the cerebral hemisphere.. | frontal parietal temporal occipital limbic and insular |
| what marks the boundary betwwn the frontal lobe and the parietal lobe? | central sulcus |
| what marks the boundary between the parietal lobe and the occipital lobe? | parieto-occipital sulcus |
| what marks the boundry between the temporal lobe and the frontal lobe? | lateral sulcus |
| what is the cerebral cortex? | entire surface of the cerebral hemisphere composed of gray matter |
| what are commissures? | bundles of axons that convey info btwn the cortices of the left and right cerebral hemispheres |
| what is the largest commisure that connects most areas of the cerebral cortex | corpus collosum |
| what are the basal ganglia nuclei in the cerebral in the cerebral hemispheres? | caudate, putamen, and globus palidus |
| where is the limbic system located? | diencephalon and cerebral hemispheres |
| the limbic system is involved with emotions and processings some types of memory...true or fals | true |
| explain how cerebrospinal fluid circulates. | circulates from inside the brain to the surface of the central nervous system and is reabsorbed into the venous blood system. |
| list the 4 ventricles tht are the cavities inside the brain. | paired lateral ventricles in the cerebral hemisphere..3rd ventricle is a midline slit in the dienccephalon...4th ventricle is located posterior to the pons and medulla |
| true or false..the ventricular system goes through the medulla and spinal cord as the central canal and ends in the caudal spinal cord. | TRUE |
| what are the meninges? | dura, arachnoid and pia |
| the dura has two projections tht seperate parts of the brain.what are they? | falx cerebri and tentorium cerebelli. |
| what is the function of the faulx cerebri? | seperates the cerebral hemispheres |
| what is the function of the tentorium cerebelli? | seperates the posterior cerebral hemispheres from the cerebellum. |
| what are the dural sinuses? | spaces in the faulx cerebri and tentorium cerebelli |
| what is the purpose of dural sinuses? | they return cerebrospinal fluid and venous blood to the jugular veins |
| how many spinal arteries supply blood to the spinal cord? | 3 |
| what are the 3 arteries tht supply blood to the spinal cord? | anterior spinal artery and two posterior spinal arteries |
| how many arteries supply blood to the brain | 2 pairs |
| what are the two pairs of arteries tht supply blood to the brain? | two internal carotid arteries and two vertebral arteries |
| where do the paired internal carotid arteries supply blood to? | anterior, superior, and lateral cerebral hemispheres |
| where do the paired vertebral arteries supply blood to? | brainstem, cerebellum and posteroinferior cerebrum |
| what is the primary blood supply to the midbrain? | posterior cerebral artery |
| the cerebrum is entirely supplied by which arteries? | internal carotid and posterior cerebral arteries |
| what is the circle of willis? | a ring of 9 arteries supplying all of the blood to the cerebral hemispheres. |
| how does the circle of willis work? | 6 large arteries anastomose(interconnection so they communicate) with 3 small communicating arteries |
| list the large arteries in the circle of willis. | anterior cerebral artery(2)..internal carotid(2)...posterior cerebral(2)... |
| list the 3 small communicating arteries in the circle of willis. | anterior communicating artery(1)...posterior communicating artery(2) |
| what id the purpose of the anterior communicating artery? | joins the anterior cerebral arteries together. |
| wht is the purpose of the posterior ommunicating arteries? | links the internal carotid with the posterior cerebral artery |
| what are the 3 major cerebral arteries? | anterior, middle and posterior cerebral artieries |
| what part does the anterior cerebral artery supply? | the medial surface of the frontal and paretal lobes |
| what part does the middle cerebral artery supply? | supplys the internal capsule, globus pallidus, putamen and caudate |
| what part does the posterior cerebral artery supply.? | supplies the midbrain and then supplies the occipital lobe and parts of the medial and inferior temporal lobes. |
| what is the function of the mitochondria? | convert nutrients into and enery source |
| what is the function of edoplasmic reticulum | rough endoplasmic reticulum synthesizes and tranzports proteins. smooth ER synthesizes and transports lipidsprotein sy |
| what is the function of ribosomes? | protein syntnthesize: free ribosomes synthesize proteins for the neurons own use. ribosomes attached to the rough ER synthesize neurotransmitters |
| what is the function of the golgi apparatus? | packages neurotransmitters |
| True of False..dendrites ar the neuronal input sites and the axon is the output unit of the cell.. | TRUE |
| what are presynaptic terminals? | transmitting elements of the neuron. |
| what are neurotransmitters? | chemicals contained in the presynaptic terminal that are released into the synaptic cleft to transmit info between neurons |
| what is the synaptic cleft? | space btwn neurons and serves as the site for interneuronal communication. |
| where are most of the neurotransmitters produced? | in the soma |
| what is anterograde transport? | when material travels from the soma along the axon toward they presynaptic terminal. |
| what is retrograde transport? | when substances are transported from the synapse back to the soma |
| list the two groups that vertebrate neurons are classified into.. | bipolar and multipolar |
| how are bipolar cells classified? | classified on the number of processes tht directly arise from he cell body. |
| what are the two direct processess tht bipolar cells have? | dendritic root and axon |
| are pseudounipolar cells a subclass of bipolar cells or multipolar cells? | bipolar cells |
| what are pseudounipolar cells? | cells tht have two axons and no try dendrites. |
| what are the most common pseudounipolar cells? | sensory neurons |
| what are the direct processess that multipolar cells have? | multiple dendrites and a single axon. |
| bipolar cells are the most common cells in the vertebrate nervouse system...True or False | FALSE...mulipolar |
| describe multipolar cell.. | specialized to recieve and accommodate huge amounts of synaptic input to their dendrites. |
| what are purkinje cells? | multipolar cells in the cerebellum |
| True of False..the nucleus, golgi apparatus, and rough endoplasmic reticulum are restricted to the soma.. | TRUE |
| a plasma membrane surround and seperates what? | surrounds the cell and seperates the extracellular environment from its contents |
| true or false..neurons function by undergoin rapid electrical potential actoss the cell membrane? | TRUE |
| what are the 4 types of membrane channels tht allow ions to flow across the membrane? | leak, modality, ligand, voltage gated |
| what would happen if we didnt have openings in the membrane channels? | without the openins throught the membrane , the membrane would be impermeable to charged molecules |
| what are modality gated channels? | they are specific to sensory neurons. |
| when do modality gated channels open? | open in response to mechanical forces(stretch, touch, pressure), temperature changes or chemicals. |
| when do ligand gated channels open? | open in response to a neurotransmitter binding to the surface of a channel receptor on a post synaptic cell membrane. |
| when do voltage gated channels open? | open in response to changes i electrical potential across the cell membrane . |
| what are voltage gated channels responsible for? | responsible for the electrical signals that are the basis of information transfer in the nervous system |
| what is the membranes electrical potential? | the difference in electrical charge, carried by ions. |
| what are three types of electrical potentials in neurons tht are essential for transmission of info? | resting membrane potential, local potential, action potential. |
| what is the resting membrane potential? | when the neuron is not transmitting information, it is the value of the elecctriccal potential across the membrane |
| what seperates the electrical charges on either side of the plasma membrane? | the cell membrane |
| what are 2 forces tht act on ions to detrmine their distribution across the plasma membrane.? | concentration gradiant and electrical gradient |
| what controls the movement of ions | the opposing chemical and electrical forces |
| what are anions | negatively charged molecules |
| what is the measurement of the resting membrane potential? | -70mV |
| is there more negative charges on the inside or outside of the neuron? | the inside |
| the distribution of a specific ion depends on what two things? | the concentration gradiant of the ion and the electrical forces acting on the ion |
| when is the cell depolarized? | when the membrane potential becomes less negative then the resting potential. |
| what does depolarized mean? | depolarization increases the likelihood tht the neuron will generate a transmittable electrical signal, and is considered excitatory |
| what does hyperpolarized mean? | decreases the neurons ability to generate and electrical signal and is considered inhibitory |
| when does alteration in membrane potential occur? | when ion channels open to selectively allow the passage of speccific ions |
| what is a local potential? | the initial change in membrane potential tht spreads only a short distance along the membrane |
| what are action potentials? | they are larger changes in electrical potential and they involve a brief, large depolarization tht can be repeatedly regenerated along the length of an axon |
| what are the recieving sites for sensory neurons? | the sensory receptors |
| what are the recieving sites for motor and interneurons? | the postsynaptic membrane |
| when is an action potential generated? | only when the electical potential exceeds the threshold level |
| how are local potentials catagorized? | either receptor potentials or synaptic potentials |
| what type of gated channels do peripheral receptors have? | modality gated channels |
| what type of gated channels do postsynaptic membranes have? | ligand-gated channels. |
| when are local receptor potentials generated? | when the peripheral receptors of a senosty neuron are stretched, compressed, deformed, or exposed to thermal or chemical agents |
| true or false..a receptor potential is purely localized to the receptive surface of the sensory neuron and can only spread passively a very short distance along the axon.. | TRUE |
| what determines whether the synaptic potential will be depolarizing or hyperpolarizing? | the action of the nurotransmitter on the membrane channel |
| true or false...depolarizing is inhibitory and hyperpolarizing is excitatory | FALSE...depolarizing is excitatory and hyperpolarzing is inhibitory |
| what is temproal summation? | combined effect of a series of small potential changes tht occur within milliseconds of each other |
| what is spatial summation? | process by which either receptor or synaptic potentials generated in different regions of the neuron are added together |
| true or false..receptor and synaptic potentials only spread passively over short distances. | TRUE |
| what is an action potential? | a large depoarizing signal thts actively propagated alog an axon by repeated generation of a signal |
| true or false..action potentials transmit information over sorter distances than receptor or synaptic potentials. | FALSE. action potentials transmit info over longer distances than receptors |
| action potentials are all or none. explain this. | this means tht every time even minimally sufficient stimuli are provided, an action potential will be produced. |
| this is an example similiar to firing of an action potential. | striking of a key on a compute keyboard, the letter will be inscribed when the sufficient amount of pressure is achieved. the shape of the leteter is not influenced by how hard the key is pressed |
| what is the threshold stimulus intensity? | the stimulus itensity thts just sufficient to produce an action potential. |
| how much depolarization is needed to trigger an action potential? | a change in membrane potential from -70 to -55mV is sufficient to trigger an action potential |
| how is the resting membrane potential restored? | restored by the diffusion of ions through leak channels |
| is it more difficult to initiate a subsequent actino potential when the membrane is hyperpolarized or depolarized? | hyperpolarized |
| when is a membrane said to be refractory? | when the membrane is hyperplarized, it is more difficult to initiate a subsequent actino potential. it is said to be refractory during this time |
| list the 2 states the refractory period can be divided into. | absolute refractory period...relative refractory period |
| what happens during the absolute refractory period? | the membrane is unresponsive to stimuli |
| what happens during the relative refractory period? | the membrane potential is returning toward its resting level and may even be hyprpolarized. |
| when does the relative refractory period occur? | during the later part of the action potential. |
| whT would happen if there were no refractory period? | the passive flow of ions associated wit an action potential could spread both forward and backward along the length of an axon |
| what is the propagation of the action potential dependent upon? | dependent upon both passive properties of the axon and actve opening of ion channels distributed along the lenghth of the axon |
| what needs to happen in an axon to keep the action potential above threshold? | the uneven distribution of ions must be maintained |
| true or false...current flow for a shorter period of time can result in membrane depolarization over greater distance | TRUE |
| the nodes of ranvier are specialized for what? | specialized for active propaation of an action potential by allowing ion flow across the membrane |
| does an action potential slow down or speed up when crossing the nodes of ranvier? | slows down |
| what is saltatory conduction? | when an action potential propagates down a myelinated axon, it quickly jumps from node to node |
| what is convergence | process by which multiple inputs from a variety of cells terminate on a single neuron |
| what is divergence? | process whereby a single neuronal axon may have many branches tht terminate on a multitude of cells |
| this is an example of convergence.. | neural input to sensory association from hearing, vision, and touch is integrated. |
| this is an example of divergence.. | the signaling of information from a pinprick |
| does divergent and convergent synaptic connections contribute to the distribution of info throughout the nervous system? | YES! |
| where are astrocytes found? | CNS |
| how are astrocytes stimulated? | by signals from adjacent neurons or by mehanical changes |
| true or false...communication between neurons and strocytes travles in both directions | TRUE :) |
| do astrocytes have synaptic contact and generate action potentials? | NO and NO. they do release neurotransmitters buy have no synaptic contacts and dont generate action potentials. |
| what do astrocytes do? | remove chemical transmitters from the synaptic cleft between neurons and clean up other debris in the extracellular space |
| true or false...oligodendrocytes and schwann cells form a protective covering caled myelin sheath.. | TRUE |
| what are neurons of the CNS myelinated by? | oligodendrocytes |
| what are neurons of the PNS myelinated by? | schwann cells |
| what do schwann cells do when peripheral nerves are inflamed? | they act as phagocytes |
| what is the overall purpose of the macroglia cells? | act as the CNS immune system and clean the neural environment |
| explain guillain-barre.. | involves acute inflammation and demyelination of peripheral sensory and motor fibers. the persons immune system generates antibodies tht atack schwann cells. |
| what might be affected by guillain-barre? | cranial nerves of the face which can cause difficulty with chewing, swallowing, speaking and facial expressions. also have deep aching pain or sensitivity to touch |
| what is plasmapheresis? | process of filtering the blood plasma to remove the circulating antibodies responsible for attacking te schwann cells |
| can a postsynaptic cell be a gland, mm cell, or other neuron? | yes |
| what does the presynaptic terminal contain? | vesicles of neurotransmitters |
| what does the postsynaptic membrane contain? | receptors |
| what binds to the receptors of the postsynaptic membrane? | specific neurotransmitters |
| where does synaptic contact between neurons occur? | occur on the cell body(axosomatic), the dendrites(axodendritic), or the axon(axoaxonic)of the postsynaptic neuron |
| what are postsynaptic potentials? | local changes in ion concentration across the postsynaptic membrane |
| what is an EPSP? | excitatory postsynaptic potentials |
| what is an IPSP? | inhibitory postsynaptic potentials |
| what is a local depolarization? | excitatory postsynaptic potential |
| what is a local hyperpolarization? | inhibitory postsynaptic potential |
| when does an EPSP occur? | occurs when neurotransmitters bind to postsynaptic membrane receptors tht open ion channels allowing a local, instantaneous flow of Na+ or Ca+ into the neuron |
| what can the summation of EPSP lead to? | generation of an action potential |
| true or false...the action of the neurotransmitter acetylcholin is always inhibitory to the mm cell.. | FALSE. its always excitatory |
| explain the IPSP.. | a local hyperpolarization of the postsynaptic membrane which decreases the possibility of an action potential |
| what happens if excitatory postsynaptic poteneials coincide with inhibitory postsynaptic potentials? | summation determines wheter an action potential will be generated |
| when is an action potential generated in the postsynaptic cell? | only if sufficient depolarizationoccurs to reach the threshold |
| a presynaptic facilitation allows what? | allows more neurotransmitters to be released |
| activity at a synapse can be influenced by presynaptiv facilitation or presynaptic inhibition? | BOTH |
| a presynaptic inhibition allows what? | allows les neurotransmitter to be released |
| neurotransmitters may excite or inhibit the postsynaptiv neuron depending on what? | depends on the molecule released and the receptors present on postsynaptic membrane |
| how do neurmodulators alter neural function? | by acting at a distance away fromthe synaptic cleft. they are usually more slow and last longer than neurotransmitters |
| what do neurons tht synapse with skeletal mm fibers use to elicit fast acting effects on mm membranes? | they use ACh. |
| what do ligand-gated ion channels consist of? | proteins tht function both as receptors for the neurotransmitter and as ion channels |
| waht are some endogenous ligands? | hormones and neurotransmitters |
| true or false...electrochemical gradients are affected by the distribution of electrical charge and teh concentration gradient of the specific ion | TRUE |
| do some ligand-gated ion channels inhibit neuronal activation? | YES |
| ion channels will open and close rapidly as long as what is present in the synaptic cleft? | the neurotransmitter |
| drugs tht effect the nervous system usually bind with what?q | bind with receptors or prebent the release of neurotransmitters or neuromodulators. |
| what is a neurotransmitter agonist? | if a drug binds to the receptor and mimics the efffects of naturaly occuring neurotransmitters |
| what is a neurotransmitter antagonist? | drugs tht prevent the release of neurotransmitters or binds to the receptor and impedes the effect of a naturally occuring transmitter |
| what is neuroplasticity? | ability of neurons to change there function, chemical profile, or structure. |
| is neuroplasticity essential for recovery from damage to the CNS? | yes! |
| what is habituation? | its a decrease in response to a repeated, benign stimulus. |
| what is habituation of the withdrawal reflex(withdrawing a limb froma painful stimulus) due to? | due to a decrease in synaptic activity between the sensory neurons and interneurons. |
| true or false? with habituation there is a decrease in the relsease of excitatory neurotransitters, including glutamate. | TRUE |
| how long after resting are the effects of habituation present? | many seconds |
| can a reflex be elicited in response to sensory stimuli after many seconds of rest? | YES |
| some children are extremely reactive to stiimulation on their skin. what is this abnormal sensitivity called? | tactile defensiveness |
| what does short-termm changes in neurotransmitter release and post synaptic receptor sensitivity result in? | a decreased response to specific, repetitive stimuli |
| True or false...long term memory requires tht synthesis of new proteins and the growth of new synaptic connnections. | TRUE |
| what is long-term potentiation(LTP)? | a cellular mechanism for the formation of memory |
| where does long-term potentiation occur? | hippocampus,motor and somatosensory cortex, cerebellum, and visual cortex. |
| long term potentiation contributes to what kind of learning? | motor, somatosensory, and visual learning |
| true of false...long term potential is not important to neural recovery following an injury or insult.. | FALSE.. long term potential is essential to neural recovery following an injury |
| what kind of harmfull consequences can long term potentiation have? | it may contribute to chronic pain syndromes including low back pain |
| with repitition of a specific stimulus, the synthesis and activation of new proteins can alter what??? | the neurons excitablity and promote or inhibit the growth of synaptic connections |
| what is the mechanism responsible for long term potentiation? | conversion of silent synapses to active synapses. |
| how are silent synapses converted to active synapses? | by long term potentiation |
| true or false..long term potentiation changes the shape of the postsynaptic membrane, producing a new dendritic spine. | TRUE |
| what must there be for a neuron to structurally change? | a genetic alteration in the cell during the learning process |
| true or false...changes in calcium within the cell are likely to be one of the signals leading to altered gene regulation during the learning process.. | TRUE |
| can magnetic stimulation improve motor memory? | yes it can :) |
| magnetic stimulation of afferent pathways induces long-term potentiation, this produces what? | produces an increase in the amplitude of exitatory postsynaptic potentials (EPSP)of an associated neuron |
| do non-neuronal cells also play an important role in brain plasticity? | yes, astrocytes change reapidly in response to changes in stimulation patterns. |
| true or false...injuries tht damage axons always cause cell death.. | FALSE..they cause degeneration but may not result in cell death some neurons have the ability to regnerate the axon. |
| if there is an injury that destroys the cell body, what happens? | it leads to cell death. when a neuron dies, the nervous system promotes recovery by altering specific synapses, functionally reorganizing the cns, and changing neurotransmitter release in response to neural activity. |
| what happens immediately after an injury when an axon is severed? | the cytoplasm leaks out of the cut ends, and the segments retract away from each other. once isolated from the cell body the distal segmemt of the axon undergoes a proccess called wallarian degeneration |
| what is sprouting? | the regrowth of damaged axons |
| name the two forms tht sprouting takes. | collateral sprouting and regenerative sprouting |
| what is collateral sprouting. | it occurs when dendrites of neighboring neurons reinnervate a denervated taraget. the target is reinnervated by branches of intact axons of neighboring neurons. |
| what is regenerative sprouting? | occurs when an axon and its target cell have been damaged. |
| where does functinal regeneratin of axons occur more frequently? | in th PNS. |
| can peripheral sprouting cause problems? | yes when an inappropriate target is innervated.EX: when motor axons innervate different mm's than they previosly did, resulting in unintended movements when the neuron is fired. |
| what is synkinesis? | unintended movements when lower motor neuron fire. |
| two types of support cells in the nervous system responsible for production of myelination are?? | schwann cells and oligodendrocytes |
| multipolar neuron cells are designed to do specific neurological tasks. can u describe the design and name an area in the cns in which their located. | they have multiple dendritic projections and are located in the cerebellum |
| several types of neuronal membranne channels exist to allow the diffusion o ions. the type of ion channels in which opens in response to a neurotransmitter is ? | ligand gated |
| a given cell membrane voltage is measured at -100 mv. we would be ccorrect in saying?? | this is hyperpolarized |
| an initiation of an action potential begins with opening of voltage gated cchannels along the membrane. we see an immediate influx of blank ions across? | sodium |
| propagation of an action potential along a neuron is immediately followed by? | polarization of the presynaptic membrane |
| temporal lobe | long and short term memory |
| cerebellum | coordination of movement |
| abstract thinking and judging is which lobe? | frontal |
| when does synkineses occur. | occurs when secered motor neurons regrow to innervate different muscles than they innervated prior to being severed |
| what happens to targets that are deprived an input due to a damaged neuron? | they can attract new inputs to maintain nerous system function |
| true or false...functional aon regeneration occurs in CNS | FALSE..it does not occur in CNS |
| what does the developement of glial scars and the absence of nerve growth factor prevent in the brain and spinal cord? | prevents axonal regeneration in the brain and spinal cord |
| what are some synaptic mechanisms our body uses to recover after an injury to the CNS? | recovery of synaptic effectivenss, denervation hypersensitivity, synaptic hypereffectiveness and unmasking of silent synapses |
| when does synaptic effectiveness occur? | once edema has resolved, the relief of pressure on the presynaptic neuron restores normal cellular function, allowing syntheses and transport of neurotransmitters which causes synaptic effectiveness to return |
| when does denervation hypersensitivity occur? | when presynaptic axon terminals are destroyed and new receptor sites decelop on the postsynaptic membrane in response to transmitter released from other nearby axons |
| when does synaptic hypereffectiveness occur? | when only some branches of a presynaptic axon are destroyed. the remaining axon branches recieve all the neurotransmitter tht would normally be shared among the terminals. |
| what is the result of synaptic hypereffectiveness? | it results in larger than normal amounts of transmitter being released on tpostynaptic receptors. |
| what is the unmasking of silent synapses? | in the normal nervous system, many synapses seem to be unused unless injury to other pathways reslutls in their activation. |
| how can coritcal maps be modified? | by sensory input, experience, and learning, and brain injury |
| true or false...changes at individual synapses reorganize the brain, which can have significant functional consequenses | TRUE |
| can people who are blind or deaf demonstrate brain reorganization? | YES...people with congenital deafness have enhanecd peripheral vision to moving stimuli, compared to hearing subjects |
| what does plasticity allow for? | allows for recovery from nervous system injury. however active movement is crucial for optimizing motor recovery |
| what can repeated stimulation of somatosensory pathways cause? | can cause increases in inhibitory neurotransmitters, decreasing the sensory cortex response to overstimulation. |
| what can understimulation of the somatosensory pathway cause? | can cause the cortex to be more responsive to weak sensory inputs |
| what happens to the neurons when the brain suffers a stroke or traumatic brain injury? | the neurons tht are deprived of oxygen for a prolonged period die and do not regenerate. |
| what is excitotoxicity? | cell death caused by overexcitation of neurons |
| do oxygen deprived neurons release large or small quantaties of glutamate? | LARGE..they release the large amounts of glutamate fro the axon terminals |
| what is glutamate? | an excitatory neurotransmitter |
| what influences the recovery of neuronal function following a brain injury? | the intensity of rehabilitation and the amount of time between the injury and initiation of rehabilitation influences the recovery |
| what could occur if there was a prolonged lack of active movement follwing a cortical injury? | subsequent loss of function in adjacent, undamaged regions of the brain. |
| true or false...task-specific practice is essential for motor learning | TRUE |
| true or false...excessive vigorous rehabilitation of motor function too soon after injury can be counter productive | TRUE |
| does rehabilitation initiated 3 to 5 days after a lesion increase or decrease the lesion size or worsen behavioral outcome? | it does NOT increase lesion size or worsen outcome |
| what are the 3 stages of development in utero? | preembryonic...embryonic..fetal |
| what is the time period for preembryonic stage of development? | conception to 2 weeks |
| what are the 3 layers of cells tht form during the preembryonic stage of development? | ectoderm...endoderm..mesoderm |
| what happens during the embryonic stage of development? | nervous system develops fromm the ectoderm |
| what happens during the fetal stage of development? | nervous system continues to develop and myelination of axons begins |
| true or false..somites appear during the fetal stage.. | FALSE... somites appear during the embryonic stage |
| what is a blastocyte? | a solid sphere of cells that happens during the preembryonic stage and is formed by repeated cell division of the fertilized ovum |
| what is the time period of the embryonic stage of development? | 2 to the end of the 8th week |
| what does the extoderm develop into in the embryonic stage? | ectoderm develops into sensory organs, epidermis, and nervous system |
| what does the mesoderm develop into in the embryonic stage? | dermis, mm, skeleton, and excretory and circulatory systems. |
| what does the endoderm develop into in the embryonic stage? | becomes the gut,liver, pancreas, and respiratory system |
| what is the time period of the fetal stage? | end of 8th week to birth |
| what happens in the fetal stage of development? | nervous system develops more fully and myelination of axons begins |
| what does the nervous system develop from? | from the ectoderm, the outer cell layer of the embryo |
| what are the 2 phases tht occur during the formation of the nervous system.? | tissues tht will become the nervous system coalesces to form a tube running alon the back of the embryo.when the end of the tube closes, the 2nd phase is brain formation |
| what is the time period for neural tube formation? | days 18-26 |
| the nervous system begins as a longitudinal thickening of the ectoderm. this is called what? | neural plate |
| where does the neural plate form? | on the surface of the embryo, extending from the head to the tail region. |
| what is the neural groove? | its when the edges of the neural plate fold and the folds grow toward each other |
| on what day of development do the folds tht create the neural grooves touch? | day 21 |
| list the sequence of the neural tube closing? | first, future cervical regions..second, it rapidly closes rostrally and caudally leaving open ends called neuroporees. |
| what are neural tubes? | open ends of the neural tube |
| how is the neural crest formed? | when cells adjacent to the neuural tube seperate from the tube and the remaining ectoderm |
| what happens to the neural tube and neural crest once the neural crest has developed? | the neural tube and the neural crest move inside the embryo |
| the overlying ectoderm tht closes over the tube and neural crest is designed to be what? | destined to become the epidermal layer of skin |
| when does the superior neuropore close? | by day 27 |
| when does the inferior neuropore close? | 3 days after the superior neuropore..30 days |
| by day 26, the neurotube differentiates into 2 rings..what are these? | mantle layer(inner wall) and marginal layer(outer wall) |
| what does the mantle layer (inner wall)contain/ | cell bodies and will becom gray matter |
| what does the marginal layer(outer wall) contain? | processes of cells, whose bodies are located in teh mantle layer. ths will become white matter. consisting of axons and glial cells |
| true or false...the brain and spinal cord develop entirely from the neural plate.. | FALSE..develop from the neural tube |
| what are somites? | as the neural tube closes, the adjacent mesoderm divides into these spherical cell clusters |
| where do somites first appear? | future occipital region |
| what is the sclerotome/ | anteromedial part of a somite |
| what does the sclerotome become? | the vertebrae and the skull |
| what is a myotome? | posteromedial part of the somite |
| what does the myotome become? | skeletal mm |
| what is a dermatom? | lateral part of the somite |
| what does the dermatome become? | dermis |
| as the cells of the mantle layer proliferate in the neural tube, grooves form on each side of the tube, seperating the tube into ventral and dorsal sections. whats the ventral section called? | motor plate |
| true or false...axons from cell bodies located in the motor plate grow out from the tube to innervate the myotome region of the somite. | TRUE |
| is a sclerotome a group of mms derived from one somite and innervated by a singe spinal nerve? | NO! a myotome is |
| true or false..in the mature spinal cord, the gray matter derived from the basal plate is called the dorsal horn.. | FALSE..Ventral Horn |
| what is the dorsal section of the neural tube called? | association plate |
| what is the gray matter in the mature spinal cord, thts derived from the association plate called? | dorsal horn |
| what do neurons in the dorsal region of the neural tube processess.? | sensory information |
| what do neurons with cell bodies in the ventral region innervate? | skeletal mm |
| what does the neural crest seperate? | seperates into columns. on eon each side of the neural tube. |
| the cells tht become peripheral sensory neurons grow 2 processes. what are these processes? | one connects to the spinal cord, and the other innervates the region of the somite tht will become dermis |
| what neurons convey information from sensory receptors to the association plate during development? | peripheral sensory neurons |
| where are the cell bodies of the peripheral sensory neurons located> | outside the spinal cord in the dorsal root ganglion |
| true or false..the peripheral nervous system, with the excception of motor neuron axons, develops from the neural crest | TRUE :) |
| as the fetus matures, the spinal column grows faster then the cord. what happens as a result of this? | the adult spinal cord ends a the l1-l2 vertebral level |
| what day during development does brain formation begin? | day 28 |
| when the superior neuropore closes, the future brain region of the neural tube expands to form three enlargements..what are these enlargements | hind brain, midbrain, and forebrain |
| the hind brain divides into 2 sections. name these | myelencephalon and metencephalon |
| is the myelencephalon the upper or lower section of the hindbrain? | upper section |
| is the metencephalon the upper or lowers section of the hindbrain? | lower section |
| what do the myelenchephalon and mentencephalon later become? | medulla, pons, and cerebellum |
| true or false...to become the cortex, the mantle layer cell bodies migrate through the gray matter to the outside.. | FALSE migrate through the white matter |
| epithelial cells tht line the neural tube divide to produce what? | neurons and glia. |
| how do neurons migrate to their final location? | by sending a slender oricess to the bran surface and hoistenein themslvs along process or climbing along radial glia. |
| function of the neuron is not genetically determined. instead, function depends on what? | depends on the area of the brain where the neuron migrates |
| how do neuron in one regino of the nervous system find the correct target cells in another region? | by a process tht emerges frm the neuron cel body. it expands to form the growth cone. the growth cone samples the enivron. contacting othr cels and chemicl cues. grwth cone recoils from sum chemicls an advnces into othr regions wher chemicls are mor compa |
| true or false...neuronal death and axon retraction sculpt the developing nervous system | TRUE |
| what is mm fiber typ dependent on? | innervation |
| what are the two types of mm fiber? | fast twitch mm and slow twitch mm |
| how is fast twitch mm fiber converted to slow twitch? | when innervated by a slow motor neuron |
| how is a slow twitch mm fiber converted to a fast twitch? | when innervated by a fast motor neuron |
| what is a myelin sheath composed of? | lipids and protein |
| when does myelination begin in developemtn? | 4th fetal month |
| when are myelin sheaths usually completed? | by 3rd year of life |
| when are motor roots of the spinal cord myelinated? | 1 month |
| when are tracts sendin info from the cortex to actiate motor neurons completely myelinated? | 2 yrs old |
| what would happen if neurons tht project from cerebral cortex to motor neurons were damaged perinataly? | motor deficits might no be observed until the child was older. |
| what is growing into deficit? | nervous system damage tht occurred earlier is not evident until the systems damaged would normally have become functional |
| when is the cns mos susceptible to major malformation during development? | between day 14 and week 20 |
| what is anencephaly? | formation of a rudimentary brainstem without cerebral and cerebellar hemispheres. |
| when does anencephally occur? | when the cranial end of the tube remains open and the forebrain does not develop. |
| true or false.. the skill does not form over the incomplete brain, leaving the malformed brainstem and meninges exposed. this is associated with anenecephally.. | TRUE |
| what is arnold-chiari malformation? | developmental deformity of the hind brain |
| explain arnold-chiari 1. | consists of herniation of the cerebellar tonsils through tht froamen magnum into the vertebral canal. medulla and pons are small and deformed. |
| what are some issues tht can occur with arnold-chiari 1? | hydrocephalus, malformation of lower cranial nerves which can cause problems with facial weakness, decreased hearing, problems with coordination. |
| abnormalities of the upper cervical cord may cause loss of ?? | pain and temperature sensation on the shoulders and lateral limbs |
| arnold-chiari 2 consists of what? | malformation of the brainstem and cerebellum leadin to extension of teh medulla and cerebellum through the framen magnum |
| what disorder is arnold-chiari 2 almost always associated with? | incomplete closure of the neural tube caled meningomyelocele |
| what is spina bifida? | neural tube defect tht resulst when the inferior neuropore dos not close. the developing vertebra dont close around an incomplete neural tube. results in a bony defect at the distal end of the tube |
| what is spina bifida occulta? | when the spinal tissue does not protrude through the bony defect. usually spinal functino will be normal |
| what is spina bifida cystic? | the meninges and sometimes the spinal cord protrude through the posterior opeining in the vertebrae. |
| what are the 3 types of spina bifida cystica? | meningocele..meningomyelocele...myeloschisis. |
| what is meningocele? | protrusino of the meninges through the bony defect |
| what is meningomyelocele? | neural tissue with the meninges protrudes outside the body.always results in abnormal growth of te spinal cord and some degree of lower extremity dysfunctino |
| what is myeloschisis? | most severe defect.. malformed spinal cord open to the surface of the body, which occurs when the neural folds fail to close |
| what is a tethered spinal cord? | end of the spinal cord adheres to one of the lower vertebra. interferes with movement control signals decendin from the brain |
| what are some physical charecteristics of fetal alchohol abuse? | small head, indistinct groove above upper lip, thin lips |
| what problems might occur with fetal alchohol abuse? | behavioral problems and cognitive movement problems |
| what can cocaine exposure in utero cause? | difficulties with attention and impulse control |
| what happens in development when cells fail to reach their normal destination in the cerebral cortex? | abnormal gyri due to abnormal number of cells in the cortex, and heterotopia(displacement of gray matter). |
| what is mental retardation associated with? | abnormalities of dendritic spines |
| how is cerebral palsy classified? | by type of motor dysfunction |
| what are the most common types of cerebral palsy? | spastic..athetoid..ataxic..mixed |
| what is cerebral palsy? | movement and postural disorde caused by permanent, nonprogressive damage of developing brain |
| what is spastic cerebral palsy? | mm shortening results in toe walking and scissor gate. |
| what is scissor gate? | one leg swings in front of the other instead of straight forward. |
| what is athetoid cerebral palsy? | the neuronal damage is in the basal ganglia. slow, writhing movements of the extremities and or trunk. |
| what is ataxic cerebral palsy? | damage is in cerebellum. incoordination, weakness, and shaking during voluntary movement |
| what is hemiplegia? | affects both limbs on one side of the body |
| what is quadriplegia? | affects all four limbs equally |
| what is diplegia? | the upper limbs are less severely affected than both lower limbs |
| true or false...most cases of cerebral palsy result from events before the onset of labor or in the newborn after delivery? | TRUE |
| what is developmental coordination disorder? | children with normal intellect, without TBI or cerebral palsy or other neurologic problems, who lack the motor coordination to perform tasks tht most children their age are able to perform. |
| what is autism? | range of abnormal behaviors including impaired social skills |
| what are the 3 autism disorders> | autistic disorder..aspergers disorder..pervasive development disorder.. |
| true or false..people with autistic disorder engage in repetitive behaviors, have limited interest, appear to lack imagination, and are uninteredted in interacting with other people. | TRUE |
| describe aspergers disorder? | they spak and have normal intelligence. limited social skills, their narrow range of interests and their repetive and frequently obsessive behaviors interfere with school, wrk, social life |
| explain pervasive developmental disorder. | indicates atypical behaviors similar to autism or aspergers |
| what are critical periods during development? | the time when nuronal projections compete for synapticc sites, the nervous system optimizes neural connections during the critical period |
| normal function of the neural systems is dependent on appropriate experience durin the critical period....true or false | TRUE!!! |
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