Term
| what does the CNS develop from? |
|
Definition
|
|
Term
| what do the PNS and ANS develop from? |
|
Definition
|
|
Term
| where do neural crest cells migrate? |
|
Definition
| to the dorsal side of the neural tube |
|
|
Term
|
Definition
| the brain and spinal cord |
|
|
Term
|
Definition
| spinal (dorsal root) ganglia, peripheral nerves |
|
|
Term
|
Definition
| sympathetic, parasympathetic and enteric nervous systems |
|
|
Term
| what is a nucleus in relation to the nervous system? |
|
Definition
| a group of neurons with related function and connections |
|
|
Term
| what does white matter contain? |
|
Definition
|
|
Term
| what is myelin formed by? |
|
Definition
|
|
Term
| True or false: all the cells of the nervous system are derived from the neural tube. |
|
Definition
|
|
Term
| what can be found in the gray matter? |
|
Definition
| neuronal cell bodies and processes, astrocytes, microglia and some oligodendroglia |
|
|
Term
| what does white matter contain? |
|
Definition
| myelinated axons formed by oligodendroglia |
|
|
Term
| True or false: all CNS cell types except microglia are derived from the neural tube |
|
Definition
|
|
Term
| what is the origin of the microglia? |
|
Definition
|
|
Term
| what type of cells are microglia cells? |
|
Definition
|
|
Term
|
Definition
| specialized cells derived from the neural tube or the neural crest; excitable cells specialized to process and communicate information |
|
|
Term
| True or False: the human CNS, the brain and spinal cord, has 200 or more functionally and morphologically distinct neuronal type |
|
Definition
|
|
Term
| where are ependymal cells found? |
|
Definition
| line ventricles of the brain and central canal of spinal cord |
|
|
Term
| what do choroid plexus cells secrete? |
|
Definition
|
|
Term
| what are the 2 types of astrocytes? |
|
Definition
| fibrous (white matter) and protoplasmic (gray matter) |
|
|
Term
| what can be found in neuronal membranes? |
|
Definition
| ion channels, receptors, and synaptic specializations |
|
|
Term
| True or False: different populations of neurons produce different neurotransmitters and neuropeptides |
|
Definition
|
|
Term
| what are the 3 regions of a neuron? |
|
Definition
| receptor region, conductive region, and effector region |
|
|
Term
| True or false: all neurons have a cell body or soma |
|
Definition
|
|
Term
| what does the cell body of a neuron contain? |
|
Definition
| the nucleus and virtually all of the protein synthetic organelles |
|
|
Term
| what does the receptor region contain? |
|
Definition
| the cell body or soma, dendrites |
|
|
Term
| where can an action potential originate? |
|
Definition
|
|
Term
| what type of chromatin does the nucleus of a neuron contain? |
|
Definition
|
|
Term
| neuronal cytoplasm is typically (basophillic or acidophillic)? |
|
Definition
| basophillic due to large amount of RER |
|
|
Term
|
Definition
| made up of RER and polysomes; reflect the high level of synthesis of membrane and secreted products |
|
|
Term
| when dendrites branch off, what is it called? |
|
Definition
| dendritic arborization or dendritic tree |
|
|
Term
| what allows for analysis of a neurons function and relations with other neurons? |
|
Definition
| the shape and orientation of the dendritic arbor |
|
|
Term
| what part of the dendrites have nissl substance? |
|
Definition
|
|
Term
| when using a nissl stain, what cannot be fully appreciated or seen? |
|
Definition
|
|
Term
| spines, thorns or gemmules are specialized regions of? |
|
Definition
|
|
Term
| if you want to be most influential on a neuron, you want to be closest to? |
|
Definition
|
|
Term
| do dendrites exhibit an action potential? |
|
Definition
|
|
Term
| what are the receptive parts of the neuron? |
|
Definition
| the cell body and dendrites |
|
|
Term
| all the inputs, excitatory and inhibitory summate to cause a? |
|
Definition
|
|
Term
| how many axons does a neuron typically have? |
|
Definition
|
|
Term
| do axons stain with nissl stains (cresyl violet)? |
|
Definition
| no because they have no RER or ribosomes |
|
|
Term
|
Definition
| tend to have uniform diameters along their entire length; they do not taper like dendrites; their contours are smooth; they branch at obtuse angles and can have branches called collaterals that come off at right angles |
|
|
Term
|
Definition
| the terminal arborizations of axons; when an axon reaches a target area |
|
|
Term
| when neurofilament synthesis goes up, axon diameter goes up or down? |
|
Definition
|
|
Term
| what are the types of things you see in slow axonal transport? |
|
Definition
| cytoskeletal components: tubulin, neurofilament proteins, actin |
|
|
Term
| what are the purpose of microtubules in the axon? |
|
Definition
| important as tracks for fast anterograde and retrograde axonal transport |
|
|
Term
|
Definition
| microtubules and neurofilaments |
|
|
Term
| neurofilaments and microtubules are transported by what type of transport? |
|
Definition
| slow axonal transport as polymers |
|
|
Term
| when neurofilaments and microtubules reach the axon terminals what happens? |
|
Definition
|
|
Term
| describe the anterograde component of fast axonal transport |
|
Definition
| conveys membranous organelles and membrane bound proteins away from the cell body toward the axon terminals |
|
|
Term
| describe the retrograde component of fast axonal transport |
|
Definition
| conveys worn organelles and endocytosed materials, such as growth factors, toxins and viruses |
|
|
Term
| what does the Rabies virus bind to? |
|
Definition
| ACh receptor of motor neurons innervating infected muscle cells; retrogradely transported to cell body where it can replicate |
|
|
Term
| what are the 2 types of synapses? |
|
Definition
| chemical and electrotonic |
|
|
Term
| what are the most common type of synapses? |
|
Definition
|
|
Term
| what is an important component of neurotransmitter release? |
|
Definition
|
|
Term
| what are 4 neural tube derivatives of CNS glial cells? |
|
Definition
| ependymal, choroid plexus cells, astrocytes, and oligodendroglial cells |
|
|
Term
| what is the bone marrow derived derivative of CNS glial cells? |
|
Definition
|
|
Term
| the anterograde component of fast axonal transport uses what as a motor protein? |
|
Definition
|
|
Term
| what is used as a motor protein for the retrograde component of fast axonal transport? |
|
Definition
|
|
Term
| what are the 2 types of astrocytes? |
|
Definition
| fibrous and protoplasmic astrocytes |
|
|
Term
| where are fibrous astrocytes typically found? |
|
Definition
| in the white matter and are also called white matter astrocytes |
|
|
Term
| where are protoplasmic astrocytes typically found? |
|
Definition
|
|
Term
| describe fibrous astrocytes |
|
Definition
| form structural support for the white matter tracts; have long slender processes packed with intermediate filaments that are composed of the protein glial fibrillary acidic protein |
|
|
Term
| describe protoplasmic astrocytes |
|
Definition
| have short, thick, bushy processes; have relatively fewer intermediate filaments than fibrous astrocytes and stain less intensely with antibodies to GFAP; these cells act as supportive cells for neurons; there is substantial evidence that they make growth factors |
|
|
Term
| describe characteristics of the blood brain barrier |
|
Definition
| the CNS has continuous capillaries with tight junctions; around the capillaries are astrocytic endfeet; experimental studies show that astrocytes induce capillaries to form the blood brain barrier |
|
|
Term
| what is an astrocytic tumor (astrocytomas)? |
|
Definition
| tumors involving cells derived from astrocytes are the most common type of primary brain tumor; they comprise 80-90% of all glial tumors in adults |
|
|
Term
| True or False: Astrocytomas have a tendency to become more anaplastic with time |
|
Definition
|
|
Term
| what is the mean survival time of an astrocytoma? |
|
Definition
|
|
Term
| True or False: Astrocytic tumors seldom metastasize to the rest of the body |
|
Definition
|
|
Term
| Some oligodendrocytes act as _____ _____ near neurons. |
|
Definition
|
|
Term
| Described by chronic demyelinating disease of the CNS with multiple plaques of demylenization |
|
Definition
|
|
Term
| what are the CNS plaques (scars) formed by in MS? |
|
Definition
|
|
Term
| what is MS characterized by? |
|
Definition
|
|
Term
| what are oligodendroglia? |
|
Definition
| myelinating cells of the CNS; myelinate up to 50 or more axons |
|
|
Term
| how prevalent is MS in the USA? |
|
Definition
|
|
Term
| has the pathogenesis of multiple sclerosis been determined? |
|
Definition
|
|
Term
| what are some of the common symptoms of MS? |
|
Definition
| unilateral visual impairment, double vision (diplopia), paresthesias (pins and needles), ataxia (unsteadiness), vertigo, fatigue |
|
|
Term
| Are microglia derived from the neuroectoderm? |
|
Definition
|
|
Term
| where are resting macrophages in the CNS derived from? |
|
Definition
| bone marrow precursor cells (monocytes) |
|
|
Term
| where do bone marrow precursor cells migrate to? |
|
Definition
| migrate into the CNS during the development of CNS vasculature |
|
|
Term
| what is the term for the microglial nuclei that enlarge and elongate due to CNS injury? |
|
Definition
|
|
Term
|
Definition
| microglia that become phagocytic due to increased damage to the CNS |
|
|
Term
| True or false: CNS injury in adults causes permanent deficits |
|
Definition
|
|
Term
| True or False: CNS regeneration is severely limited in adults |
|
Definition
|
|
Term
| when astrocytes react to injury, what is it called? |
|
Definition
|
|
Term
|
Definition
| forms a glial scar; occurs when astrocytes react to injury; inhibit aonal regeneration |
|
|
Term
| what does the dorsal root ganglion contain? |
|
Definition
| sensory neurons that signal pain and temperature, touch, pressure, vibration, and proprioception |
|
|
Term
| what are the 3 connective tissues of the peripheral nerve? |
|
Definition
| epineurium, perineurium, and endoneurium |
|
|
Term
| where in the peripheral nerve is the site of the blood-nerve barrier? |
|
Definition
|
|
Term
| what does guillan-barre syndrome affect? |
|
Definition
|
|
Term
| describe guillan-barre syndrome |
|
Definition
| acute inflammatory polyradiculoneuropathy; usually bilateral, symmetrical, motor weakness; may be an autoimmune disease; severe cases can lead to death; most cases resolve in 2-4 weeks |
|
|
Term
| can peripheral nerves regenerate after injury? |
|
Definition
|
|
Term
| when is peripheral nerve regeneration best? |
|
Definition
| when the peripheral nerve is crushed since the CT sheaths stay intact |
|
|
Term
| what cells play a critical role in peripheral nerve regeneration? |
|
Definition
| schwann cells; become phagocytic and synthesize essential growth-promoting factors and cytokines |
|
|
Term
| what are the structural and molecular changes in a neuronal cell body triggered by when an axon is severed by trauma? |
|
Definition
| a loss of target-derived neurotrophic factors |
|
|
Term
| when an axon is severed (axotomy), the neuron exhibits the? |
|
Definition
| axonal reaction: the cell body swells, there is a dissolution of nissl substance (chromatolysis); the nucleus moves to an eccentric position |
|
|
Term
| what genes are up-regulated during the axotomy response? |
|
Definition
| actin and tubulin; needed for growth cone and axon regeneration |
|
|
Term
| what are down-regulated during the axotomy response? |
|
Definition
| neurofilament genes and genes associated with synaptic transmitters |
|
|
Term
| describe the 2 parts of the severed axon and which portion is attached where |
|
Definition
| proximal attached to neuronal cell body, distal separated from the cell body |
|
|
Term
| where does the proximal portion of the severed axon degenerate back to? |
|
Definition
| the next node of Ranvier (retrograde degeneration) |
|
|
Term
| what are the morphological changes to axotomy? |
|
Definition
| chromatolysis- dissolution of RER, movement of nucleus to eccentric positon |
|
|
Term
| what are the biochemical changes to axotomy? |
|
Definition
| decrease in synthesis of less-essential proteins (neurofilament proteins, transmitter proteins), increase in synthesis of proteins needed for axonal regeneration (tubulin and actin proteins) |
|
|
Term
| what is an axonal growth cone? |
|
Definition
| a motile structure that has a concentration of receptors for neurotrophic factor and laminin |
|
|
Term
| describe neural plate formation |
|
Definition
| At the beginning of the 3rd week of embryonic development, the notochord induces the overlying ectoderm to form the neural plate. By the end of the 3rd week, the lateral edges of the neural plate form neural folds and the depressed mid-region forms the neural groove. |
|
|
Term
|
Definition
|
|
Term
| fusion of the neural folds in neurulation occurs in what directions? |
|
Definition
|
|
Term
| the neural canal is open to the amniotic cavity via what 2 pores? |
|
Definition
| rostral neuropore (cranial opening) and caudal neuropore |
|
|
Term
| what does closure of neuropores coincide with? |
|
Definition
| the establishment of a blood supply for the neural tube |
|
|
Term
| where is the spinal cord derived from? |
|
Definition
| the neural tube caudal to the 4th pair of somites |
|
|
Term
| what is the brain derived from? |
|
Definition
| the neural tube rostral to the 4th pair of somites |
|
|
Term
| what are the 3 zones of spinal cord development? |
|
Definition
| ventricular zone, intermediate zone, and marginal zone |
|
|
Term
| describe the ventricular zone in spinal cord development |
|
Definition
| region of cell proliferation; cells become neurons and macroglia |
|
|
Term
| describe the intermediate zone (mantle layer) in spinal cord development |
|
Definition
| neurons differentiate and form axons and dendrites |
|
|
Term
| describe the marginal zone in spinal cord development |
|
Definition
| area at edge of cord where longitudinal axon fasicles grow |
|
|
Term
| what does the alar plate become in spinal cord development? |
|
Definition
| becomes sensory (afferent) portion of cord |
|
|
Term
| what does the basal plate become in spinal cord development? |
|
Definition
| becomes motor (efferent) portion of the cord |
|
|
Term
| where is the dorsal (posterior) horn derived from? |
|
Definition
|
|
Term
| where is the ventral horn derived from? |
|
Definition
|
|
Term
| what are the 3 primary vesicles that form in brain development? |
|
Definition
| forebrain, midbrain, hindbrain |
|
|
Term
| what are the 5 secondary vesicles in brain development? |
|
Definition
| telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon |
|
|
Term
| what are the 3 flexures of brain development? |
|
Definition
| midbrain, pontine, cervical flexure |
|
|
Term
| what are the 2 components of the autonomic nervous system? |
|
Definition
| sympathetic and parasympathetic |
|
|
Term
| what are the 2 neuron systems in the autonomic nervous system? |
|
Definition
| preganglionic neuron in CNS, postganglionic neuron |
|
|
Term
| describe preganglionic neurons in the sympathetic nervous system |
|
Definition
| in the spinal cord lateral horn from T1-L2 or 3; some synapse in paravertebral ganglia; others travel via splanchnic nerves to prevertebral ganglia; cholinergic |
|
|
Term
| describe postganglionic neurons in the sympathetic nervous system |
|
Definition
| in paravertebral or some prevertebral ganglia; most are adrenergic except to eccrine sweat glands |
|
|
Term
| describe preganglionic neurons in the parasympathetic nervous system |
|
Definition
| located in the brainstem nuclei or sacral spinal cord; cholinergic |
|
|
Term
| describe postganglionic neurons in the parasympathetic nervous system |
|
Definition
| in wall of viscera, cholinergic |
|
|
Term
| what are some predominant features of a motorneuron in a slide? |
|
Definition
| euchromatic nucleus, prominent nucleolus, abundant Nissl substance |
|
|
Term
| Some neurons, such as the Purkinje cells of the cerebellum have dendrites characterized by _______ protrusions. |
|
Definition
|
|
Term
| what are neurofilaments believed to be important in maintaining? |
|
Definition
|
|
Term
| what happens when retrogradely transported endosomes and multivesicular bodies reach the cell body? |
|
Definition
| they fuse with lysosomes; material is digested |
|
|
Term
| can lipofuscin be digested? |
|
Definition
| no; accumulates with age and in some diseases |
|
|
Term
| how are cell bodies and dendrites identified in double-label immunofluorescence? |
|
Definition
|
|
Term
| how are synaptic terminals identified in double-label immunofluorescence? |
|
Definition
|
|
Term
| what is the glia limitans? |
|
Definition
| the joined end-feet processes of astrocytes coating the pia mater |
|
|
Term
| what are examples of 2 toxins that are retrogradely transported? |
|
Definition
| tetanus toxin and ricin toxin |
|
|
Term
| the epidermis and neural tissue arose from what germ layer? |
|
Definition
|
|
Term
| the muscle and connective tissues arose from what germ layer? |
|
Definition
|
|
Term
| the epithelial linings of the GI tract and respiratory tracts arose from what germ layer? |
|
Definition
|
|
Term
| the cerebral hemispheres arise from what secondary vesicle in brain development? |
|
Definition
|
|
Term
| the midbrain arises from what secondary vesicle in brain development? |
|
Definition
|
|
Term
| the pons and cerebellum arise from what secondary vesicle in brain development? |
|
Definition
|
|
Term
| the medulla arises from what secondary vesicle in brain development? |
|
Definition
|
|
Term
| the thalami arise from what secondary vesicle in brain development? |
|
Definition
|
|
Term
| what are the three components of the autonomic nervous system? |
|
Definition
| symphathetic, parasympathetic, and enteric |
|
|
Term
| where are the regions where migrating neurons may reside? |
|
Definition
| dorsal root ganglion, sympathetic ganglion, preaortic ganglion, organ plexus |
|
|
Term
| preganglionic neurons in the sympathetic are mainly? (cholinergic or adrenergic) |
|
Definition
|
|
Term
| postganglionic neurons are mainly? (cholinergic or adrenergic) |
|
Definition
| adrenergic (epinephrine or norepinephrine) |
|
|
Term
| True or false: the sympathetic nervous system goes to all parts of the body. |
|
Definition
|
|
Term
| True or false: every spinal nerve has sympathetic innervation associated with it. |
|
Definition
|
|
Term
| the intermediolateral cell column is characteristic of the ______ cord. |
|
Definition
|
|
Term
| the prevertebral ganglia receive preganglionic axons via the ______ nerves. |
|
Definition
|
|
Term
| where are preganglionic neurons that have their axons in the splanchnic nerves typically found? |
|
Definition
in the intermediolateral cell column of the spinal cord at the following levels:
Greater T5-T9
Lesser T10-T11
Least (T11)-T12 |
|
|
Term
| what viscera type do the greater, lesser, and least splanchnic nerves innervate? |
|
Definition
| abdominal viscera but arise in the thorax |
|
|
Term
| what are the 4 things an axon leaving the intermediolateral cell column may do once they enter the sympathetic chain? |
|
Definition
They may ascend in the chain and synapse in more rostral ganglia.
They may descend in the chain and synapse in more caudal ganglia.
They may pass through the chain without synapsing and go to a prevertebral ganglion.
They may synapse in the ganglion at the same spinal level from which they arose. |
|
|
Term
| what does the white communicating ramus contain? |
|
Definition
| myelinated preganglionic sympathetic axons |
|
|
Term
| what does the gray communicating ramus contain? |
|
Definition
| unmyelinated postganglionic axons |
|
|
Term
| postganglionic sympathetic neurons like to follow _____ _____ to reach their targets. |
|
Definition
|
|
Term
| what is Horner's syndrome characterized by? |
|
Definition
| ptosis (partial drooping eyelid) and miosis (small pupil) |
|
|
Term
| where are preganglionic neurons found in the parasymathetic branch? |
|
Definition
| located in the brainstem nuclei or sacral spinal cord; cholinergic |
|
|
Term
| where are postganglionic neurons found in the parasympathetic branch? |
|
Definition
| in the wall of viscera; cholinergic |
|
|
Term
| what are the 2 plexuses formed in the enteric nervous system? |
|
Definition
| submucosal (meissner's plexus) and myenteric (Auerbach's plexus) |
|
|
Term
| True or false: the enteric nervous system can work in the absence of input from the brain and spinal cord. |
|
Definition
|
|
Term
| what does the myenteric plexus regulate? |
|
Definition
| peristalsis and sphincters |
|
|
Term
| what does the submucosal plexus regulate? |
|
Definition
| secretion by glandular epithelial cells; motility or muscularis mucosa; some may be sensory neurons that help signal presence of material in lumen |
|
|
Term
| what are the events involved in peristaltic reflex? |
|
Definition
Bolus of material distorts mucosa
Enterochromaffin cells release serotonin (5-HT)
5-HT stimulates nerve endings in lamina propria
Cell bodies of these sensory neurons in the submucosal (Meissner’s) plexus
Sensory neurons activate motor neurons in myenteric (Auerbach’s) plexus |
|
|
Term
| what kind of nucleus does auerbach's plexus normally have? |
|
Definition
|
|
Term
| what is hirschsprung's disease? |
|
Definition
Also known as congenital aganglionic megacolon
There is a failure of neural crest cells to migrate into the distal colon
1:5000 births
Males affected more than females 4:1 |
|
|
Term
|
Definition
Formerly called cardiospasm
Onset 25-60 years
Men=women
Loss of myenteric neurons (Auerbach’s plexus) in lower the esophagus
Lower esophageal sphincter (LES) paralyzed in constricted state
Esophagus dilated
Acquired disease; usually a postviral infection |
|
|
Term
| pain afferents travel with the ________. |
|
Definition
|
|
Term
| stretch afferents travel with the _______. |
|
Definition
|
|
Term
|
Definition
Pain associated with visceral disease and inflammation is referred to the abdominal wall.
This is because visceral nociceptive (pain) afferents enter the spinal cord with somatic afferents.
All pain fibers run with the
sympathetic system and enter the spinal cord at the same segment that gives rise to the preganglionic efferents. |
|
|
