Lecture 2 Flashcards

Question

What are the cells of the nervous system?

Answer 1

Neurons Glia (CNS) Satellite cells (PNS) Hundreds of billions

Answer 2

``` Specialized cells for electrochemical signals -reception -conduction -transmission LOOK IN TEXTBOOK ```

Answer 3

Nerve fiber = nerve process(axon or dendrite) Nerve = bundle of nerve fibres in PNS Tract= bundle of nerve fibres in CNS Ganglion = cluster of neuronal cell bodies in PNS Nucleus = cluster of neuronal cell bodies in CNS

Answer 4

``` Largest glial cell -9 subtypes Star shaped Provide metabolic support to neurons Clean up neurotransmitters Signal NTs Hold neurons in place - rearrange synapses -control establish and maintain synapses Regulate ions in extracellular space Regulate blood floe to activate regions Form BBB Astrocytes sanctum : connected by gap junctions ```

Answer 5

``` Really small Macrophages -engluf debris Multiply in response to injury/disease -mediate cell death Activate immune defence - antibodies can't pass bbb Fast acting Synaptic plastcity (formation or pruning) Sensitive to changes in K+ ```

Answer 6

``` Only in the CNS Extensions wrap around axons -multiple axons -mulitple segments Rich myelin Form myelin sheath -speed condution -nourish axon -white matter - necessary for complex nerve interaction -occurs for 20 years postnatally ```

Answer 7

Only in PNS Each cell has only one axon segment Guide regeneration (only can occur in PNS)

Answer 8

Composed of fats and proteins • Synthesized by oligodendrocytes and schwann cells • -Wrapped 250X+ • Speed conduc2on • Saltatory conduc2on • Jump • Not all axons myelinated • Large diameter • Providenutrientsto segments far from cell body • Loss=MS

Answer 9

Glia REGENERATE • SUPPORT NEURONS • MORE NUMEROUS THAN NEURON Neurons MULTIPLE PROCESSES (DENDRITES, AXONS, AND SYNAPSES) • CANNOT REGENERATE • REQUIRE GLIA TO SURVIVE

Answer 10

``` First axis • Anterior= nose or front • Posterior=tail or back • Second axis • Dorsal=top of head (think dorsal fin) • Ventral=bodom of head • Third axis • Medial=midline • Lateral= away from middle ```

Answer 11

``` Links brain to body & body to brain • 2 nerve roots • Dorsal • Sensory=afferent • Unipolar • Ventral • Motor=efferent • Mul2polar • 31 pairs • 4 regions • Cervical • Thoracic • Lumbar • Sacral • 2% of CNS • Major site of injury • Diagnose nature and loca2on of injur ```

Answer 12

``` White mader in periphery • Myelinated axons • Grey mader in middle • Cell bodies • Unmyelinated • Buderfly or H-shaped • CSF in central canal • Differs across 4 regions • Lower regions grey:white is higher • Lower level has less afferent & efferent nerves ```

Answer 13

* Consists of neuronal cell bodies, interneurons and glia * 4 main columns * Dorsal horn * Somatosensory nuclei * Axon terminals of sensory nerves * All levels of spinal cord • Ventral horn * Motor neurons dendrite and cell body * Innervate skeletal muscle (SNS) or internal organs (ANS) * Lateral horn * Intermediate column * Autonomic nerves innervate visceral and pelvic organs (also lateral horn)

Answer 14

``` “ENCEPHALON” • IN THE HEAD BRAIN DEVELOPS AS 3 SWELLINGS • FORE • Forms into tele and di • MID • HIND • Met and myel ```

Answer 15

``` • Most posterior—in hindbrain • AKA medulla • Ascending and descending tracts at core • Origin of re2cular forma2on • Core network of 100 nuclei • Also composes core of hindbrain and midbrain • Arousal system (re2cular ac2va2ng system) • Not really func2oning as a system ```

Answer 16

``` Acsending and descending tracts • Cerebellum • Sensorimotor coordina2on • Maintain fine motor skills • Role in cogni2on/language/ aden2on • Pons • Contains re2cular forma2on • Swelling on ventral surface of brainstem • Transfer informa2on between the brainstem and the ```

Answer 17

* Midbrain * Tectum “roof” * Superior collliculi • visuomotor * Inferior colliculi * Tegementum * Re2cular forma2on (arousal) • Red nucleus (sensorimotor) * Motor coordina2on: gait • Hemoglobin and ferra2n * Substan2a nigra (sensorimotor) * Reward, addic2on, and movement • Melanin * Periaqueductal grey (analgesia) • Defensive behaviour * Gate control theory of pain * Releaseendorphinsanddense endorphin receptors * Stimulaton=analgesia

Answer 18

* Thalamus * 2 lobes * Massa intermedia * Runs through third ventricle to connect * Sensory relay nuclei :see appendix V * LGN: vision * MGN: audi2on * Ventral posterior nuclei: touch * Feedback bidriec2onal to and from Thal ctx * Consciousness?

Answer 19

* Hypothalamus * Under the thalamus * Pituitary gland suspended by hypothalamus * Release hormones via pituitary gland that modulate behaviour * Stress * Reproduc2on • Feeding * Mammillary bodies * Op2c chiasm • Decussate * Contralateral • ipsilateral

Answer 20

``` • Cerebral hemispheres separated by longitudinal fissure • Corpus callosum • Largest tract connecting 2 hemispheres • Cortex convolutions • Gyri (hills) • Sucli/fissures (valleys) • Largest division of human brain • Controls sensory perception • Limbic system • Basal ganglia ```

Answer 21

``` 4 lobes defined by fissures, not unitary system • Frontal • Parietal • Central fissure • Occipital • Temporal • Lateral fissure • STG=auditory • IFT=object identity • MTL=memory • Longitudinal fissure • Between hemispheres • Precentral gyri • Primary motor cortex • Postcentral gyri • Primary somatosensory cortex • Superior temporal gyri • Auditory cortex • Prefrontal cortex • Nonmotor portion of frontal lobe ```

Answer 22

* 6 layers * Layer 1 at surface * Differ in * Size of cell body * Density of neurons * Proportion of cell types * Thickness * Varies across brain * Columnar organization * Vertical flow of information * Mini circuit

Answer 23

* 2 types of neurons * Pyramidal * Large * Multipolar * Large dendrites * Apical dendrites * Reach surface * Long axon * Stellate * Interneurons * Small * Star-shaped

Answer 24

* Regulation of motivated behaviours * 4 Fs * Feeding * Fleeing * Fighting * Sex * Structures circle thalamus * Primitive cortex * Hippocampus * Spatial Learning and memory * Cingulate cortex * Subcortical structures * Amygdala * Emotional memory * Fear and anger * Kluver-Bucy syndrome * Fornix * Tract * Hippocampus -> septum * Septum * Anterior tip of cingulate cortex * Mammillary bodies

Answer 25

* Motor system * Voluntary * Procedural learning * Deep subcortical structures * Amygdala * Part of both limbic and bg * Nucleus accumbens * Medial ventral striatum * Reinforcement learning * Drug reward learning * Striatum (caudate nucleus+putamen) * Striped * Projections from substantia nigra * Depleted in PD * Globus pallidus