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87 Cards in this Set
- Front
- Back
Anatomical Structure and Function of Neuron |
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Cell Body (Soma) |
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Dendrites |
Receives messages from other cells |
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Axon |
Passes messages away from the cell body to other neurons, muscles, or glands |
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Action Potential |
Electrical signal traveling down the axon |
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Myelin Sheath |
covers the axon of some neurons and helps speed neural impulses. |
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Node of Ranvier |
These gaps in the myelin sheath help the conduction of nerve impulses |
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Generation of Action Potential |
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Electrochemical Gradient |
- Potassium (K) on inside - Na+ and Cl- on outside - Potassium will defuse out and Nitrogen flow in |
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Voltage Gated Channels in Membrane |
Next 4 Slides |
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Threshold Potential |
Voltage reaches certain level, causing voltage gated Na+ channels to open |
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Depolarization |
Na+ flow in creating a positive charge voltage gated |
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Repolarization |
K+ flow out, reversing charge, making it negative Na- channels begin to close |
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Hyperpolarization |
Sodium-potassium pump combined w/ K+ flowing out, lowers charge of cell |
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Saltatory Conduction |
A form of nerve impulse conduction in which the impulse jumps from one Ranvier's node to the next, rather than traveling the entire length of the nerve fiber. |
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Graded Potential |
- Can be anywhere - Relative to the stimulus (opens specific channel) - Excitatory or Inhibitory |
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Steps of Synaptic Transmission (6 Steps) |
1. Voltage gated ion channels open 2. Calcium rushes in 3. Calcium binds to vessels, pulls them down, and allows them to bind to synaptic cleft 4. Vessel bind to pre-synaptic membrane, open up, and release neurotransmitters into synaptic cleft 5. Neurotransmitter is going to bind to spefic channel to it 6. Once bind, channel opens up (confirmational change). Neurotransmitter is booted out, and gate closes |
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EPSP's |
- Excitatory Post-Synaptic Potentials - they increase the likelihood of a postsynaptic action potential occurring |
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IPSP's |
- Inhibitory Post-Synaptic Potentials - they decrease the likelihood of a postsynaptic action potential occurring |
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Differences Between Graded Potentials & Action Potentials |
Graded: - Anywhere on Neuron - Relative to stimulus - Dissipates Action - Occurs on axon - All-or-nothing - Remains strong - Refractory period |
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Motor Unit - What is it? |
- Smallest unit of motor control - A motor neuron and all the muscle fibers it innervates |
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Motor Unit - What does it do? |
Neuromuscular Junction: calcium mediated Ach release - Causes muscle action potential -> twitch or muscle contraction |
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Motor Unit Size/Force Principle |
Next 4 slides |
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Small Motor Unit |
Slow twitch Slow to fatigue Low threshold Few muscle fibers |
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Medium Motor Unit |
Moderate muscle fibers Fast twitch Slow to fatigue Moderate threshold |
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Large Motor Unit |
Fast twitch Fast to fatigue High threshold Many muscle fibers |
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Size Principles |
- Order of motor unit recruitment to accomplish a movement task is from small to large - Why? -> Smallest motor neurons must have the lowest threshold for activation because they're all small in diameter |
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Firing Properties of a Motor Neuron can Affect Force Generation |
- Rate Coding - Asynchronous (less force) / synchronous Firing (More force) - Low Rate = less force - High Rate = more force - Speed (velocity) of contraction impacts force generation - Muscle length impacts force generation - Biomechanics of improvement - Types of levers impact force and velocity |
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Golgi Tendon |
- Located near tendon/muscle contraction - Fire in response to active contraction - Function = To protect from tearing muscle (autogenic inhibition - Important role in over contracting muscle |
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Proprioceptor |
Tells us where our limbs are in gravity |
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Deaffrentation |
Cutting Sensory information off - Fire in response to movement of joint - Minor role in propriceptor |
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Cutaneous Receptors (6) |
1. Meissner's Corpuscle (light touch) 2. Merkle's Corpuscle (touch) 3. Free Nerve Ending (Pain) 4. Pacinian Corpuscle (Vibration and Deep Pressure) 5. Raffini Corpuscle (warmth) 6. Hair Receptor (touch) |
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Motor Pool |
consists of all individual motor neurons that innervate a single muscle |
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Brainstem Reflexes What causes the blink reflex? What's the resulting movement? |
You blink when something comes close to your face |
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Brainstem Reflexes Vestibulo Ocular Reflex |
Even if your head moves, the eyes move in the counter direction |
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Tonic Asymmetric Reflex (Neck Reflexes) |
Doing opposite movements |
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Symmetric Reflex (Neck Reflexes) |
Doing the same movement |
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Startie Reflex (Neck Reflexes) |
Arms go up to protect |
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Righting Reflex (Balance/Posture) |
Velocity or excelleration of head (not position of head) Fall down -> head goes up |
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Primary Motor Areas |
Primary Motor Cortex (M1) -> Sends out signal |
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Secondary Motor Areas |
1. Premotor Area (PMA) 2. Supplementary Motor Area (SMA) 3. Cingulate Motor Area |
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Secondary Motor Areas: Function of Premotor Area (PMA) |
- Receive info from cerebellum - External initiation, sensory driven |
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Secondary Motor Areas: Supplementary Motor Area (SMA) |
- Receives info from basal ganglia - Internal initiation, intention driven |
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Secondary Motor Areas: Cingulate Motor Area |
- Motivation/desire - Sudden Insight - Participates in long term memory |
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Homunculus What is it? Where is it found? Where is it most abundant? |
- In the primary motor cortex area, in both hemispheres - Largest representation in the face and mouth - Fine motor units, tongue, etc.. |
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Basal Ganglia (Multiple Nuclei) |
- Sends information to the Cerebral Cortex |
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Basal Ganglia is involved in... |
Before and during movement - Selecting movement options -> Cognitive set -> Motor set - ballistic force generation - Internally generated - Movement sequencing - bimanuel coordination |
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Brain stem controls what movements? |
Automatic |
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Brain Stem Tracts? (5) |
1. Tectospinal 2. Reticulospinal - 3. Vestibulospinal 4. Corticospinal 5. Rubrospinal |
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Brain Stem Tracts: Tectospinal |
eye and head movements |
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Brain Stem Tracts: Reticulospinal |
trunk and proximal limb movements for locomotion and postural control |
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Brain Stem Tracts: Vestibulospinal |
Position of head and limbs to support positive balance |
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Brain Stem Tracts: Corticospinal |
Descending command from M1 -> finger movements |
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Brain Stem Tracts: Rubrospinal |
Redundant w/ corricospinal tracts except for individual finger movements |
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Hair Cells in Hearing |
- Sound waves deflect the hair cells in the cochlea opening channels -> mechanoreceptors - Signal is transmitted through several brainstem centers and then thalamus before reaching primary auditory cortex |
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What are the sensory structures in the vestibular system? |
- Fluid filled semicircular canals - neolithic organs are located inside canals and contain cupola and ampulla |
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Hair cells in the vestibular system fire in response to what? |
Linear and angular of the acceleration |
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Difference between Ambient and Focal vision? |
Ambient - Not conscious - relatively fast - not fully focusing in on a object Focal - conscious - relatively slow - focusing in on something/recognizing it |
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Advance visual information? How does this influence movement? |
- gaining info prior to movement - Location, size, weight, texture, where object is relative to self |
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Movement Disorders ALS |
Due to cell death of upper motor neurons in cortex. Very uncommon |
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Movement Disorders Stroke |
Due to internal capsule blood clot, or even a hemorrhage |
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Movement Disorders Multiple Sclerosis |
Due to death of myleninated cells |
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Movement Disorders Spinal Cord Injury |
result from damage to the vertebrae, ligaments or disks of the spinal column or to the spinal cord itself. |
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Movement Disorders Progressive Supernuclear Palsy |
Due to cortical basal degeneration, multiple system atrophy |
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Movement Disorders Cerebral Palsy |
Cerebral palsy is caused by brain injury or brain malformation that occurs before, during, or immediately after birth while the infant’s brain is under development. |
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Movement Disorders Corical Basal Degeneration |
Corticobasal degeneration (CBD) is a rare progressive neurological disorder characterized by cell loss and deterioration of specific areas of the brain. Affected individuals often initially experience motor abnormalities in one limb that eventually spreads to affect all the arms and legs. |
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Parkinson's Disease Cause? Where does cell loss occur? |
- No clear cause - Occurs in the spinal cord |
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Parkinson's Disease Main Motor Symptoms |
- Bradykinsea - Akinsea - Rigidity - Tremor - Postural Instibility` |
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Huntington's Disease |
Cause -> Genetic Produces to much dopamine |
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Main symptoms of Huntington's Disease |
- Chroea and ticks - Movement - Mood/emotion - Thinking - Attention/memory |
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Causes of Huntington's Disease |
Caused by death of brain cells in the brain *Mostly occurs in Basal Ganglia* |
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Cause and Symptoms of Cerebellar Damage |
Cause - Progressive Symptoms - poor coordination - ataxic gait and reaching - difficulty in balance - dysmetria - intention tremeor |
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Symptoms of Basal Ganglia Dysfunction |
- Movement changes, such as involuntary or slowed movements. - Increased muscle tone. - Muscle spasms and muscle rigidity. - Problems finding words. - Tremor. - Uncontrollable, repeated movements, speech, or cries (tics) - Walking difficulty. |
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Prenatal Development - Major Time Points |
- Notochord develops at 18 days - 20 days, Neural Plate folds up - 22 days, neural plate closes, forming neural tube - 24 days, have what's becoming the spinal cord - 25 days -> neural tube -40 days -> Forebrain, Midbrain, Hindbrain, spinal cord 100 days -> Major parts of brain are formed |
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When do gyri and sulci begin to develop? |
20 to 22 weeks |
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When do reflexes begin to develop? |
20 to 22 weeks |
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What does the Telencephalon give rise to? |
1. Olfactory Lobes 2. Hippocampus 3. Cerebrum - Smell - Association - Memory Storage |
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What does the Diencephalon give rise to? |
1. Retina 2. Epithalamus 3. Thalamus 4. Hypothalamus - vision - pineal gland - relay center for optic/auditory neurons - Temp, sleep, breathing regulation |
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What does Mesencephalon give rise to? |
Midbrain - Fiber tracts between anterior and posterior brain, optic lobes, and tectum |
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What does the Metencephalon give rise to? |
Cerebellum Pons - Coordination of complex muscular movements - Fiber tracts between cerebrum and cerebellum |
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What does the Myelencephalon give rise to? |
Medulla - Reflex center of involuntary activities |
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Postnatal Development Birth - 6 months |
- There is minimal addition of neurons, but their are additions of trillions of connections - The size of neurons increase through dendritic branching and mylination |
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Postnatal Development 6 months - 6 years |
- Brain continues to make new connections, but also begins to purge away connections not being used and strengthen those that are - Brain weight triples |
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Postnatal Development 6 - 20 years |
- Prune and myelinate - Different rate of maturing -> occipital lobe (1 year) -> Temporal lobe (6 years) -> Prietal Lobe (6 years) ->Frontal Lobe (20 years) |
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Environmental Factors influence postnatal development Enriched and Impoverished |
Enriched - myelination increases - dendretic growth Impoverished - cell loss |
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Neural Changes that Happen with Aging |
- Decrease in brain weight - loss of dendritic spines - Plaques and Tangles - Cell death - Decrease in neurotransmitters |
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Envi Factors that affect aging brain Exercise |
Larger brain size More white and gray matter |