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Description
Flashcards by Jillian Lynch, updated more than 1 year ago
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Created by Jillian Lynch
about 8 years ago
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| Question | Answer |
| What are the 3 organization principles of the brain? | 1. Localization of Function 2. Laterilization of function 3. Topographic Representation |
| How many output systems do we have? | We have one output system known as the motor system |
| What are some of the conditions that affect the motor system? | -ALS -stroke |
| What is Human Motor Control? | Human Motor Control is the study of posture and movements and the mechanisms that underlie them. |
| In which situations will 100% of your brain be used? | 100% of your brain will be used while you are hit by lighting, having an epileptic seizure, or sitting in an electric chair. It is not realistic or normal to have more than 20% of your brain active at a given time. |
| What areas of the brain are involved with planning to hit a tennis ball? | Visual cortices – which see the ball Premotor Cortex which plans the movement Amygdala and Hypothalamus provide memory of the sport and best decision to make in order to return the tennis ball. |
| CNS consists of 7 main regions: | 1. Spinal cord 2. Medulla 3. Pons 4. Midbrain 5. Cerebellum 6. Thalamus 7. Cerebral hemispheres |
| What is Excitability? Which cells are excitable? | Excitability is a neutrons ability to produce electricity and pass current. Neurons are excitable and release ions onto the next set of neurons. |
| What are the 3 types of neurons: | Sensory Neurons: are 1 ended receptors in the muscles, eyes, or skin, etc. that provide info about world to our CNS. Sensory neurons are also known as afferent neurons (arrive in the nervous system) Receive information through dorsal horn. Motor neurons: Also known as Efferent neurons: send information out through ventral horn to the final common pathway. Interneurons: Located in between the Sensory and Motor neurons. Ensure that the correct information is sent in it’s correct direction. |
| Alpha Motor neuron: | lower motor neuron (the workhorses- they take all of your thoughts, and desires to perform your output behavior). Located in the ventral horn of the spinal cord. Innervate muscle. |
| What happens if I have a contusion in my spinal cord? | Once a contusion occurs the person may need to learn how to walk again or how to perform several other movements (depending on the severity and location). A contusion causes the circuitry to be disrupted and plasticity needs to occur to repair movement. |
| White matter- | where the travelling happens (nerve fibers/ tracts) Fatty substance. Acts as insulation for neural electrical conduction (inside of brain) |
| How do sodium channels influence the positive charge on the inside of the cell? | Typically there is a set of doors (nodes of ranvier) which need to be opened for positive to enter. Positive enters through the sodium channels. |
| How does the cell depolarize? | Inhibitory postsynaptic potential. Chloride is usually on the outside but it is opened to all Chloride in to make the cell more negative. |
| what is spatial summation? | 1000's of inputs from thousands of presynaptic neutrons at once |
| What is temporal summation? | input from one presynaptic neutron in quick succession. -Very important! JUST ONE! |
| Convergence | information from several sources is being sent to one neutron. |
| Divergence | One neuron that sends out signals to several other neurons. (spilt the cable) |
| Terminating the postsynaptic potential | You have released vesicles containing neurotransmitters, but if you have too many neurotransmitters it is known as neurotoxicity or habituation-too much of a certain neurotransmitter reduces your sensitivity to it (drug addiction). |
| Glia cells (astrocyte) | The pit crew clear out neurotransmitter so that it can be broken down and used again later |
| Cocaine | Blocks dopamine reuptake. which allows dopamine to sit and saturate the receptors of the synaptic cleft. Ultimately affects mood. |
| Alcohol Cerebellum and Frontal Cortex | Facilitates postsynaptic (GABA) stimulation. This keeps chloride channels open. Which means you will require anymore EPSPs in order to achieve action potential. Takes longer to process information. |
| Alpha Motor Neuron | The last point that your brain has connection with. Ventral horn. |
| Motor Unit: is an alpha motor neuron and all the fibres it innervates | It's size depends on it's function. large muscle groups are going to have very large motor units. small motor units are found in the eye. Thumb has both small and large power units |
| Motor Neuron pool | all the motor neurons affecting a single muscle |
| Intrafusal Muscle Fibres | Detect change in muscle length |
| Motor Neuron types | Alpha Motor Neuron: innervate extrafusal muscle fibres. Contraction control. Gamma Motor Neurons: innervate muscle spindles. Sensitivity Control. |
| cortical motor areas can control alpha motor neurons and the brainstem (higher levels monitoring lower areas) | travel through the cortical tract to communicate with the Alpha Motor Neurons |
| Tectum (roof of midbrain) | Medial brainstem pathway From Tectum to tectospinal tract (where crossover occurs) to spinal cord |
| Vestibular spinal tract: 5 accelerometers in ears which land on alpha motor neurons which are set off by gravity. constantly sending a tonic signal to inform you of where you are | Does NOT cross over controls postural stability and it is very important that is is near the spinal cord to quickly send a signal to re-stabilize. |
| Reticulospinal tract Reticular means web like | Ipsilateral-des NOT cross over Brain stem to spinal cord Very important for posture of axial and proximal muscles. |
| Lateral brain stem pathways: GOAL directed movements not used as much in humans as in animals | Heirachy in the brain-takes over control of movements. our rubrospinal tract is not as active as animals. Cats can still move their hind legs with a severed spinal cord. |
| Humans have a Lateral Corticospinal tract | True |
| M1 Neuroplasticity | Your motor mapping changes based on what is being used. if you lose a finger or a limb you will have better control over other areas to make up for the lack of control in one area. |
| PMA lesions | impairs movement made by sensory cues |
| SMA lesions | disrupts self-initiated movements and impairs bimanual coordination alien hand syndrome |
| Imagining a sequence of movements | activates 30% of motor units |
| true or false: the Basal Ganglia made of ganglia | False. It is made of nuclei |
| What two parts of the basal ganglia make up the striatum? | Caudate and Putamen |
| Input into the Basal Ganglia: | striatum |
| Output from Basal Ganglia | Globus Pallidus Interior Substantia Nigra |
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