Module 6 - Nervous system

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what are the two major branches within the nervous system? how do these divisions sub-branch.
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like the frontal lobe, the parietal lobe contains __________, which serve a similar purpose - what is that purpose?somatosensory association areas - these serve to integrate somatosensory information with other associations areas to create a meaningful perception.cerebellum - aka? what three major functions does this do?little brain processes sensory information and also coordinates execution of movement of the body and corrects ongoing movement.which brain structure houses the largest number of neurons?cerebllum. this structure actually contains more neurons than the rest of the brain combined.the cerebellum receives input from which three sources?somatic receptors receptors for equilibrium balance/motor neurons from the cortex.which brain structure is involved in modification of some reflexes?cerebellumwhich brain structure is involved in pavlovian conditioning and the vestibular ocular reflex? does the cerebellum work to ensure muscles are doing what they are supposed to be doing?the cerebellum processes information leaving from the PMC going to muscles, but it also processes proprioceptive information coming from the muscles. compares these two pieces of information and modifies output from the PMCthe temporal lobe houses _______. what else is contained here? what are the functions of these regionsprimary auditory cortex auditory association areas. receives and processes signals from the auditory nerve and integrates them with other sensory input.which brain structure contains regions known to process olfaction and mediate short term memory storage and recall?temporal lobe.which brain structure is responsible for processing vision? what is housed here? where does this receive input from? what else is housed here like the other areas of the brain we've looked at?occipital lobe primary visual cortex optic nerve associations areas that integrate input from the optic nerve with other sensory input to create a meaningful perception.what brains structures are visible from a medial view? (4)corpus callosum pituitary gland diencephalon brain stemwhat is the corpus callosum? what is its function?it is a bundle of nerve fibres that serves to connect the two cerebral hemispheres. allows integration of motor and sensory input from both sides of the body.pituitary gland regulates _________.endocrine organsanterior pituitary is derived from ...?epithelial tissues of the pharynxposterior pituitary is derived from ...?neural tissue from the hypothalamusanterior pituitary hormones?FLAT PIGwhat is the function of the thalamus?receive sensory input coming from the body and integrate sensory information before sending it off to different parts of the cortex/what is the function of the hypothalamus? how? where is it located?processes endocrine functions. through the release of hormones into the blood. located at the base of the brain, anterior to the brain stemMidbrain - aka? - bridges what two structures? - what does it control? (3)mesencephalon lower brain stem and diencephalon eye movement and auditory/visual motor reflexespons - relay station for transferring information between what two structures? what does this do?cortex and the cerebellum assists in the control of breathing along with the medulla.medulla oblongata - portion of the brain that controls _______, such as _________ - fibers from the ______ (originate from the _______), do what?involuntary movements like blood pressure, breathing, swallowing corticospinal tract (originate from the motor cortex) and cross over to opposite sides and go innervate parts of the body.from the ventral view, what can we see?optic nerves brain stemoptic nerves from each eye meet at the ______, where they do what? where do they go? from here where do they go?optic chiasma, where they cross over and continue on as optic tracts to the lateral genticulate bodies of the thalamus. from here, the information is directed to their respective hemispheres on the PVA of the occipital lobe.what can we see from the dorsal view?primary motor cortex primary somatosensory cortex language and math areasmath and language areas are most often found in which hemisphere?left hemisphere.what cells make up 90% of the brain? what do these do? what makes up the rest?glial cells, provide the necessary environment for the neurons to function properly. Neuronsthere are three types of neurons - what are they? how are they classified?bipolar, unipolar, multipolar. classified based on the number of processes that emerge from the cell body.what are bipolar cells and where can they be found?soma has two processes that emerge from it. can be found in the retina of the eye.what are unipolar cells? where are these found? how are the cell bodies oriented?only one process extending from the soma. typically found in the PNS and are sensory in nature cell bodies are typically found pushed off to one side of the axonmultipolar cells - ? - location?contain multiple processes extending from the soma found in the CNSglial cells - what do these do? (2) how do they do it? three types of glial cells?support cells of the brain (gluing things together) and maintain the environment of the CNS (interstitial environment of the brain and nutrients) glial cells are able to execute their roles by regulating the passage of things between the blood brain barrier. astrocytes microglia oligodendrocytes.what is neural coding - give an example? what does this require? what is the general rules?neural coding is the process by which different stimuli are coded differently WRT the firing rates of the AP from receptor to brain. heavier objects have higher firing rates. this requires neurons to communicate with each other as the AP make their way to the brain. stronger stimuli have higher firing rates (higher frequency)the structure of the chemical synapse is as follows 1. __________ - contains ________, _________, lots of _______ 2. _________ 3. _________ contains _______, ________pre-synaptic neuron axon terminals that contain voltage gates calcium channels, synaptic vesicles with Nt in them and lots of mitochondria synaptic cleft post-synaptic neuron which contains chemical receptors and ligand gated ion channels.what the the 6 general steps that occur in the chemical synapse1. Nt are synthesized and stored in synaptic vesicles within the pre-synaptic axon terminals 2. an AP travels down the axon and reaches the axon terminal of the pre-syn neuron. this triggers voltage gated calcium channels to open and calcium rushes into the axon terminal 3. the influx of calcium triggers the binding of synaptic vesicles to the membrane, and the exocytosis of the Nt. 4. Nt diffuse across the syn cleft, and bind to receptors on the post syn neuron 5. binding of Nt triggers the opening of ligand gated ion channels 6. depending on the Nt released, the post syn neuron will either locally depolarize or hyperpolarize.Nt can either be _______, in which case they produce ________ or they can be ______, in which case they produce _______excitatory, local depolarization inhibitory - hyperpolarization.what are the 4 major classes of Nt. how are they categorized?Ach Biogenic amines Neuropeptides amino acids categorized based on chemical structurewhere does Ach take its effect?at the NMJwhat are some examples of biogenic amines?catecholamines, dopamine, epinephrine and norepinephrine.what are the two categories of amino acid Nt? give an example of eachexcitatory - Glutamate --> most common inhibitory - GABA --> most common.what are neuropeptides? e.g.?endogenous opioids - endorphin -VIPwhat is the main difference between a chemical synapse and the NMJ?at the NMJ, a single AP from the motor neuron can stimulate the muscle to transmit the AP and initiate a contraction. at the chemical synapse a single AP coming from the Pre-Syn neuron will NOT generate an AP on the Post-Syn neuron.the Ligand gated ion channels on the Post-Syn neuron are sensitive to ________, and will often allow the influx of _______. will this generate an AP? if not, what does it generate?positive ions sodium into the cell No. it generates a local depolarization of the Post-Syn membrane called an EPSP.what are EPSPs and what are characteristic of these phenomena?EPSPs are excitatory post synaptic potentials - these are local depolarization events that diminish in strength over time and distance from the source.EPSPs trigger local depolrizations - are these APs? why or why not? how can an EPSP generate an APThese are NOT APs. there are no voltage gated Ion channels on the dendrites or the cells body of the neuron. you need voltage gated channels to generate an AP, and these are found at the axon hillock. an EPSP can generate an AP if it is strong enough to reach the axon hillock and trigger depolarization here.what are the two ways we can achieve a strong enough EPSP?spatial summation temporal summationwhat is spatial summation?the additive effect of many pre-syn neurons that stimulate one post-syn neuron at the same time. EPSPs spread from many synapses to the axon hillock, which if depolarized will fire an AP.what is temporal summation?the additive effect produced by many EPSPs that have been generated at the same synapse by a series of high frequency APs from the pre-syn neuroninhibitory Nt produce _________ called an _______.hyperpolarizations inhibitory post synaptic do IPSPs work? two mechanismsthey produce a hyperpolarization by opening different ligand gated ion channels. they can either open Chlorine channels to let chlorine in or potassium channels to like K out.IPSPs are similar to EPSPs in that they are ____(2)local events can spatial or temporally summate.what is synaptic integration?this refers to net effect of thousands of synapses on a single post synaptic neuron. which one wins - EPSPs or IPSPs. after determining this, the cell can either hyperpolarize or generate an AP.what 7 structures can we say belong to the somatic motor system?supplamentary motor area pre motor area PMC spinal tracts nerves that go to and from the brain and muscles muscle receptors basal ganglia.describe the sequence of events that occur in the frontal lobe if you want to pick up a cup of coffeeyou see the cup of coffee and think "i want to pick this up". the thought is generated in the prefrontal cortex. signals are passed to the premotor cortex, which develops the "plan" of movements that you'll need to pick up the cup. once you've developed the plan of movements, signals are sent to the supplementary motor areas to program muscles that will be used in your plan. programming what muscle will do what, and with what strength once the program is written, the code is sent to the PMC, where neurons will be activated and stimulate the appropriate muscles.the PMC is oriented along the pre-central gyrus. it can be topographically mapped out to represent parts of the body that will be stimulated.see a picture for this. motorhomonculus.signals from the PMC travel down the _________.corticospinal tractthe corticospinal tract is the major pathway from the ______ to the _______ - where are the cell bodies? - as it travels to the spinal cord, what happens as it passes over the medulla? what happens when the fibres reach the level of the spinal cord where they will synapse with motor neurons?PMC to the motor neurons that innervate muscle cells - PMC - the the tract passes the medulla, the majority of fibres cross over to the contralateral side of the body, while a small minority remain on the ipsilateral side. once at the level of the spinal cord where they synapse, the fibres on the ipsilateral side now cross onto the contralateral side.what is proprioception? how is this possiblethe muscle sense that allows the brain to be aware of the positions of the limbs in space and the extent of contraction of muscles at all times. this is possible because of receptors in muscle that send signals back to the brain.which two receptors allow proprioception to occur? define eachmuscle spindles - detect, stretch, length, and rate of change of length golgi tendon organs - detect muscle tensionmuscle spindles are found in the _______, adjacent to the _________ (aka - ?)whole muscle real contractile tissue (extrafusal fibres).muscle spindles consist of (4)intrafusal muscle fibres central sensory region 2 sets of gamma motor neurons that activate the intrafusal fibres and sensory neruons that originate from the sensory region.when the whole muscle stretches, what happens to the sensory region of the spindle? what is it sensitive to?it also stretches and triggers AP in the sensory nerve that get sent to the brain. the brain interprets stretch and location in space. sensitive to changes in shape.signals that travel from the brain to the muscle do so along ________. what happens when this is the only input? (2). how do we solve this problem? what is this called/alpha motor neurons. if this is the only input, only the extrafusal fibres would be stimulated. the intrafusal fibres would go slack and information from the spindle to the brain would not be transmitted. to solve this problem and keep intrafusal fibres active as well, during a muscle contraction, commands are simultaneously sent through gamma motor neurons to the intrafusal fibres. alpha gamma co-activation.the reflex arc is an integrated neural process - what 6 things does it require?sensory receptor afferent neurons at least one synapse sometimes interneurons efferent fibers effector organhow does a reflex arc begin? what happens next? then?Reflex arc begins in the sensory receptor, which produces a receptor potential that triggers an AP in the afferent neuron. next, the AP enters the spinal cord where it synapses with interneurons and then efferent neurons efferent neurons stimulate the effectorwhat is the key defining feature of a reflex arc?it does not require any input from the brain to generate a muscle contraction.provide and describe an example of a reflex arcstretch reflex tapping the patellar tendon causes the quadriceps muscle to contract and stretch, and the hamstring muscles to relax.the limbic system is the __________, and is made up of these structures. (5). How are these structures oritented. what is the function of these structures?emotional centre of the brain - amygdala - hypothalamus - hippocampus - cingulate cortex - septum these structures form a ring around the brain stem. these structures link higher ordered thought processes with more primitive emotional responsesthe autonomic nervous system controls things that are __________. eg?not under voluntary control. - breathing rate, - heart rate - pupil diameter - smooth muscle contractionswhat are the two major divisions of the ANS?sympathetic nervous system parasympathetic nervous systemthe sympathetic nervous system regulates what response? how does it do this? where do the nerves exit for this system? describe the structure of the neurons invovled and how they communicatefight or flight response - increases HR, bp, dilates airways and blood vessels in the muscles. constricts blood vessels in the digestive system nerves exit at the thoracic and lumbar regions pre-ganglionic neurons are short and synapse in ganglia onto a second postganglionic neuron (long) that travels to the effectorPSNS regulates what? how does it do this? where do the nerves for this system exit? describe the structure of the nerves involved and how they communicate with each otherstorage and conservation of energy. rest and digest lowers bp and heart rate. nerves exit at the brains stem and lower sacral regions the pregang neuron is long and synapses with a post gang neuron near the effector organ.pre-gang neurons that leave the spine in both the SNS and PSNS release the Nt __________acetylcholinewhich branch of the ANS can sometimes release more than one Nt onto the effector organ? what are these two Nt? what about the other branch?SNS. Ach and NE the PSNS always deals in Ach.which body tissues receive only SNS input? (don't receive PSNS input) (4)adipose tissue adrenal blood vessels kidneysee table for the functions of the ANS from notes----------