NEUR 1203 Midterm I PDF

2/7/25, 5:39 PM NEUR 1203 MIDTERM I NEUR 1203 MIDTERM I coordinates actions by transmitting signals to and fr...

2/7/25, 5:39 PM NEUR 1203 MIDTERM I NEUR 1203 MIDTERM I coordinates actions by transmitting signals to and from different parts of its body detects environmental changes (ie. eyes detect the nervous system (NS) changes in light,colour..etc.) responds to certain events (ie. reflexes, moving out of the way) divided into central NS and peripheral NS part of the somatic nervous system 12 pairs of nerves that control sensory Cranial Nerves information to CNS connects the brain and the internal organs, thereby influencing several autonomic responses brings sensory information in from periphery to Afferent nerves CNS, functions include sensation to eyes, ears ,mouth ,and nose brings sensory information out, functions Efferent nerves include motor control over facial muscles, tongues and eyes The 12 Cranial Nerves 1. Olfactory (smell) 2. Optic (vision) 3. Oculomotor ( eye movement) 4. Trochlear (eye movement) 5. Trigeminal (masticatory movements, facial sensations) 6. Abducens (eye movement) 7. Facial (facial movements, sensations) 8. Auditory vestibular (hearing and balance) 9. Glossopharyngeal (tongue/pharynx movement & sensation) 10. Vagus (heart, blood vessels, viscera, movement of larynx and pharynx) https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 1/14  11. Spinal accessory (neck muscles) 2/7/25, 5:39 PM NEUR 1203 MIDTERM I 12. Hypoglossal (Tongue muscles) functionally equivalent to cranial nerves of the head, extends from spinal cord Spinal nerves control and carry information about the body, trunk & limbs each spinal nerve integrates sensory info throughout the body bilaterally symmetrical, each vertebrae has a dorsal and ventral root collection of fibers entering and exiting the Spinal Cord spinal cord segment is called a root dorsal root/fiber: afferent away from finger tips to spinal cord (in) ventral root/fiber: efferent, carries sensory info out 1. fibers entering the dorsal root bring sensory information from sensory receptors 2. fibers leaving the ventral root carry Steps of spinal fibers motor information to the muscles 3. collateral branches of sensory neurons may cross to the other side and influence motor neurons there 4. white-matter fiber tracts carry information to and from the brain Dorsal spinal cord is sensory Ventral side is motor and they both send info to the CNS Law of Bell & Magendie allows inferences about location of spinal - cord damage on the basis of changes in sensation or movement that a patient experiences Autonomic NS divided into sympathetic and parasympathetic division Sympathetic Division activating system fight or flight response https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 2/14  connected to thoracic & lumbar regions 2/7/25, 5:39 PM NEUR 1203 MIDTERM I spinal cord connects to autonomic control center, made up of ganglia (spinal connections to many ganglionic centre) increased heart rate, breathing, blood pressure…etc. calming system rest & digest pathway Parasympathetic Division connects through cranial nerves 3,7,10 also connectd to sacral region of spinal cord - allows for all other processes to occur spinal cord - control centre of the entire body vertebrae: segments of the spinal cord divided into 5 anatomical regions ( from top to bottom) Dermatomes : segments of the body, each dermatome contains sensory nerves & motor nerves, controls most body movement, divided into sections Central nervous system Cervical (C1 - C8) very top of spinal cord Thoracic (T1 - T12) Lumbar (L1 - L5) lower back Sacral (S1 - S5) can act independently of the brain, spinal relfex, autonomic movements, hard for brain to inhibit Dura mater: tough double layered fibrous tissue; encloses brain & spinal cord Arachnoid layer: thin sheet of delicate connective tissue; follow the brains contour protecting you brain and creates space for CSF Pia Mater: moderately tough membrane of connective tissue; clings to brain surface - directly attached like glue all of these layers are called meninges meningitis inflammation of the meninges, bacterial infection of the meninges, particularly the pia mater and arachnoid space CSF is implicated aswell https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 3/14  subarachnoid space is filled with CSF between 2/7/25, 5:39 PM NEUR 1203 MIDTERM I pia mater and arachnoid layer Intra Cranial Pressure (ICP) inflammation puts pressure on the brain which can lead to drowsiness, delirium and coma Frontal lobe: executive function,decision making, planning, impulse control, etc.. works with parietal lobe for goal directed movement 4 Lobes of the brain Parietal Lobe: Tactile function, senspry & motor information processing -movement Occipital Lobe: visual function, visual cortices Temporal Lobe: auditory, visual, gustatory, emotion and memory Cerebrum: forebrain structure, two idendical hemispheres, responsible for most conscious behaviour - outerpart of the brain Cerebellum (ie. little brain) controls and Dorsal and ventral views of the brain coordination of fine motor skills; does not initiate movements, but coordintes the timing, precision and accuracy of movements - animals that are faster or move a lot more have bigger cerebellums (ie. cheetah vs sloth) brainstem: resposnible for unconscious behaviours, structurally continuous with the spinal cord (sits under cerebellum) Gyri: bumps & ridges of the cerebral cortex Sulci: cracks & valleys of the cerebral cortex (fissures are known as deep sulci) lateral & medial view of the brain together gyri and sulci create a larger sufrace are for the human brain larger cortical surface area = greater cognitive functioning lateral fissure - goes very deep and is the longest sulci in the brain, seperates the frontal and parietal lobes from the temporal lobe aka central sulcus cerebral arteries 1. anterior cerebral artery 2. Middle cerebral artery 3. Posterior cerebral artery https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 4/14  3 major arteries that supply the 2/7/25, 5:39 PM NEUR 1203 MIDTERM I cerebrum blockage of any of these leads to regional death = stroke there are three so that of there is blocklage, there will still be some part of the brain that can still work but the region being blocked can completely die Gray matter: largely composed of cell bodies and capillary blood vessels; processes information and supports behaviour - outerportion of the brain White matter: nerve fibers with fatty coverings; forms connections between cells, sends information to outer layer Inside the brain ventricles: 4 cavities filled with cerebral spinal fluid, derived from blood plasma, NaCl and other salts, 3 main functions are buoyancy,cushioning, immune support ( our brains are very heavy anf=d it helps releive some weight cells that line the walls of the ventricles are called ependymal cells and they produce CSF largest white matter tract that connects the right and left hemispheres over 200 million nerve fibers that connect the 2 Corpus Callosum hemispheres; divides brain into cortical (above corpus callosum) and subcortical regions (below corpus callosum) allows us to interact with both sides of the brain simultaneously acts as a divisor. corpus callosum prevents cross talk between hemispheres because the language center of the brain is on the opposite side of dominant side split brain most of the brain is symetrucal some functions (ie. language) is localized to one side patients with a cut corpus callosum cant name objects in their left visual field https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 5/14 2/7/25, 5:39 PM NEUR 1203 MIDTERM I all information travels through receives afferent nerves from all the body’s senses and sends efferent nerves to the spinal the brainstem cord, it is divided into 3 distinct regions: 1. hindbrain 2. midbrain 3. diencephalon consists of.. cerebellum : controls fine motor movement pons: connects the cerebellum to the rest of the brain the hindbrain reticular formation: located at the core of the brainstem; netlike mixture of grey and white matter, helps send signals between the spinal cord and the brain medulla: controls breathing and cardiovascular system Tectum: dorsal side of midbrain, recieves sensory information from the eyes and ears, allows production of oriented movements (reflexes) Tegmentum: superior colliculus (receives visual input) and inferior colliculus receives auditory Midbrain information, inside includes… red nuclei: motor coordination of the limbs substantia nigra: initiates voluntary movements - dopamine system periaqueductal grey matter - sexual behaviour and pain largest and most recently evolved, controls perception, movement etc. mostly found in mammals divided into 4 parts forebrain 1. the neocortex 2. basal ganglia 3. allocortex - limbic system 4. olfactory system https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 6/14 2/7/25, 5:39 PM NEUR 1203 MIDTERM I controls certain aspects of voluntary movements, procedural learning and habit fdormation, consists of caudate nucleus basal ganglia putamen globus pallidus subtsantia nigra above the brainstem deeper in the brain but still considered cortical, includes.. hippocampus: memory storage, particularly spatial memories; neurogenesis (production of new neurons) Allocortex amygdala: emotional regulation, fear acquisition, memory enhancement and activation - info feeds into HC to create memory cingulate cortex: helps certain aspects of memory formation and recollection which helps respond to future events part of limbic system contains olfactory bulbs - permits the sense of smell, sends sensory information directly to pyriform cortex for processing relatively small in humans compared to other Olfactory system animals (eg. dogs, rats,cats) plays a very significant role in memory formation - since its part of the limbic system, any other system goes directly to hypothalamus but this one goes through allocortex then hypothalamus hypothalamus - controls hormone production Diencephalon thalamus - relay station that sends all information where it needs to go parts of a neuron 1. soma - core region, processes information 2. dendrites - brancing extensions, collects information and sends it to https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 7/14  the axon, the # of dendrites = amount 2/7/25, 5:39 PM NEUR 1203 MIDTERM I if incoming information 3. dendritic spines: small synapses on a dendrite that serve as a point of contact with other axons 4. axon hillock: point at which the axon leaves the soma (cell body) 5. axon: carries information to other neurons through white matter tracts 6. myelin sheath: insulates axons, signals travel faster and further, electrical transmission 7. axon collaterals: point at which axon branches out: allows messages to be sent in multiple directions simultaneously 8. terminal button: stops extremely close to dendritic spine of anotjer neuron, does not touch other neurons at the end of axon collaterals 9. synapse: junctio between one neuron and the other; space between the terminal buttom and dendritic spine, where NTs are released neurons carry out the brains major functions brings information to the brain (afferent), structurally they are the simplest type of sensory neurons neuron with one single dendrite on one side, cell body and single axon on the other side, subtypes of this neuron are… bipolar neurons - retinal bipolar cell somatosensory neurons - multipolar cell links sensory and motor neurons, branch extensively to collect more information subtypes include… stellate cell (star shaped): very small, many interneurons dendrites, extending around entire cell body - in thalamus pyramidal cell (pyramid shaped): long axon with mulitple sets of dendrites - in cortex purkinje cell: output cell, extremely branched dendrites - in the cerebellum https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 8/14 2/7/25, 5:39 PM NEUR 1203 MIDTERM I carry information (motor instructions) from brain into spinal cord and muscles (efferent), extensive dendritic networks to collect Motor neurons information from multiple sources, large cell bodies to process information, all outgoing information must pass through motor neurons to reach target muscles. includes upper and lower motor neurons cells that provide insulation and support to all neurons, they are like the parnts of neurons, and they take care of them, types of glial cells include: 1. ependymal cell: located on walls of ventricles, produces CSF and very small 2. astrocyte: provides structural support, holds neurons in place, regulates the blood brain barriers, produced in the Glial cells bloodsteam , star shaped and symmetrical which allows for more blood flow, glucose and oxygen 3. oligodendrocytes: insulates axons in the CNS, assymetrical, forms myelin around axons in the brain and spinal cord, can wrap around multiple axons at once through white matter tracts 4. Shwann cell: insulates axons in the PNS, assymetrical, wraps around peripheral nerves to form myelin A nerve is cut or severely damaged. The section of the nerve that is no longer connected to the main cell (neuron) starts breaking down because it can’t get nutrients anymore. Special immune cells (like Schwann cells in the wallerian degeneration PNS or microglia in the CNS) come in to remove the debris. In the peripheral nervous system (like in your arms and legs), Schwann cells help guide the axon to regrow. However, in the central nervous system (like the brain and spinal cord), regrowth is very limited. https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 9/14 2/7/25, 5:39 PM NEUR 1203 MIDTERM I 1. proximal axon regresses and the distal decomposes 2. shwann cells grow and form myelin 3. neurons send out axon sprouts neuronal repair glial cells 4. shwann cells shrink and form a path sometimes axons get lost and projects somewhere else or never comes, repair is much less common in CNS due to complexity and it does not have shwann cells axons carry information that connects neurons to each other nerves when outside the CNS and tracts within the CNS how do neurons communicatea? neurotransmission occurs in two steps 1. electrical 2. chemical for on neuron to communicat with another neuron, it must use both electrical and chemical signals part of electrical communication each neuron has a resting membrane potential - at rest the cell has no stimulus this occurs because the cell is negative membrane potential charged inside and positively chathed outside cell membranes are permeable, it is difficult to pass through which is why cells travel through channels resting potential is -70mV large protein anions are made inside the cell and cant leave ( negatively charged) maintaining membrane potential ungated potassium and sodium channels are free moving positive ions travel through a potasium sodium pump electrochemical gradient help neurons send signals by controlling ion movement. Ions move due to two forces: 1. Electrical force (opposites attract, like charges repel). https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 10/14  2. Chemical force (ions spread from 2/7/25, 5:39 PM NEUR 1203 MIDTERM I high to low concentration). At rest, the neuron is more negative inside. When activated, ions move, changing the charge and creating a nerve signal. without stimulus a cell will remain at -70mV a stimulation is required to elicit a change in membrane potential hyperpolarization: membrane potential is potential changes in electrical communication exagerated, so difference between inside and outside are greater depolarization: membrane potential is diminished, so difference between inside and outside are lessened stimulus - opens channels brief but very large, reverses the polarity in the axons membrane the inside of the cell becomes positive, relative actrion potential to the outside which becomes negative this change is abruptly reversd, thanks to an influx of potassium and then goes back to -70mV neurons receive both excitatory and inhibotry inputs: excitatory pos-synaptic potentials (EPSP) and inhibitory post-synaptic potentials (IPSP) spatial summation: presynaptoc neurons reaching threshold release NT at different locations, combined signals trigger an action potential temporal summation: single presynaptic neuron releases NT repeatedly over a short period of time, overlapping signals add up to trigger an action potential when EPSP reaches -50mV which is the threshold to trigger a response initiation of action potential large influx of sodium to do channels opening and potasium leaves the cell all or nothing —> continues until inside the cell reaches +30mV https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 11/14 2/7/25, 5:39 PM NEUR 1203 MIDTERM I Sodium and potassium channels are gated until -50mV is reached sodium channels are faster and open first, then what happens at -50mV? a second gate closes once reached +30mV no more sodium at peak action potential potassium channels are slower and take longer to close = repolarization 1. stimulus - signal or change that triggers cell to respond 2. threshold (-50mV) - minimum charge needed for the neuron to activate and start sending a signal 3. depolarization (influx of sodium) - sodium rushes into the neuron making it positively charged 4. peak ( + 30mV) - chage inside the Action Potential Steps neuron reaches its highest point during activation 5. repolarization - potassium moves out of the cell brining the charge back down 6. refactory period - neuron briefly recovers, can fire again but would need an even stronger stimulus 7. returning to resting state - neuron goes back to -70mV ready for next signal In myelinated neurons, the signal jumps between gaps (nodes of Ranvier) for faster action potential propogation transmission (saltatory conduction). if we have a larger action potential but our axons are not very large/thick, myelin doesnt cover the whole axon chemical transmission how information is passed to the next cell? through the release of neurotransmitters NTs are released in the synaptic clef (space between two terminals) NT = chemicals that can be excitatory or inhibitory vesticle: storage of NT https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 12/14  synaptic cleft: space between button and spine 2/7/25, 5:39 PM NEUR 1203 MIDTERM I post-synaptoc receptor: binding side of neurotransmitter 1. must be synthesized in the neuron or otherwise be present in it 2. when the neuron is active the transmitter must be released and produce a response in some target 4 main criteria for a molecule to be classified 3. the same response must be obtained as a neurotransmitter when the transmitter is experimentally placed on the target 4. a mechanism must exist for removing the transmitter from its site of action after work is done all NT are chemicals but not all chemicals are NT 1. monoamine: dopamine, norepinephrine, epinephrine, serotonin and histamine types of NT 2. amino acid: GABA, glutamate, glycine, D-serine 3. Peptide: spmatostatin, subtance P 4. Transmitter gases: nitric oxide, carbon monoxide 1. synthesis - synthesized from DNA and stored in vesicles 2. Release — transported to pre-synaptic membrane, released in response to 4 steps of chemical transmission action potential 3. receptor action: activates target receptors on post synaptic membrane 4. inactivation: 4 different ways that the NT is taken back into terminal or stops working removal of NT’s can be removed or inactivated in four main ways: 1. Reuptake – The NT is sucked back into the neuron that released it (like recycling). https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 13/14  2. Enzyme Breakdown – Special 2/7/25, 5:39 PM NEUR 1203 MIDTERM I enzymes break down the NT (like cutting it into pieces). 3. Diffusion – The NT drifts away from the synapse (spreads out naturally). 4. Glial Cell Uptake – Nearby support cells (glia) absorb and remove the NT. https://knowt.com/flashcards/bd3b7942-cc51-4692-a4e7-8b882f042a52 14/14