Neural Basis for Motor Control Learning Flashcards
Does size of our brain matter?
- No, makes up 2% of our body mass.
- 25% of body energy
- Uses 500kcal per day.
- 2000kcal/day diet.
What is the function of a neuron?
- Information messengers.
- Use electrical and chemical signals to send info between different areas or the brain, spinal cord, and body.
How many neurons do we have?
- Average: 86 billion
- 16 billion in the cerebral cortex.
What is the function of dendrites?
- Receive information from other cells (input)
What are neurotransmitters?
- Chemicals that carry signals from cell to cell.
What is the function of the cell body?
- Integration of information in the cell.
- Also called soma, or initial segment, initiates action potential.
- Takes info from all dendrites and compiles it in the axon hillocks
What is the function of the Axon?
- If signal from dendrites is strong enough, it gets sent to the axon.
- At this point, the signal is called action potential.
What is Myelin?
- Covers axon to prevent signal from degrading as well as speeds up signal.
What are axon terminals?
- Output.
- Once signal reaches axon terminal, neurotransmitters are released.
- Also called synaptic buttons.
What are the different types of neurons?
- Sensory neurons
- Motor neurons
- Local interneurons
- Projection interneuron
- Neuroendocrine cell
Hydrophilic
- Attracted to water
Hydrophobic
- Afraid of water
Why is the charge of resting potential -70?
- There are more negatively charged K ions inside the cell and more positively charged Na ions outside of the cell.
What is Membrane Potential?
- Refers to the difference in electrical charges inside and outside of a neuron.
Plasma Membrane
- Separates inside of the cell from the rest of the environment.
Ions
- Atoms that have either lost or gained electrons thus have a pos or neg charge.
Anion
- Neg charged ions
Cation
- Pos charged ion
Concentration Gradient
- Passive form of diffusion.
- Movement of ions from areas or high concentration to low concentration.
Electrical Gradients
- Difference in charge across a membrane.
How does sodium and potassium move in and out of cell membrane?
- Sodium goes inside via electic and concen.
- Potassium goes outside via concen, and inside via electic
How is the resting membrane potential maintained?
- For every 3 positively charged sodium ions leaving the cell, two negatively charged potassium ions enter, making it so the cell or neuron is more negative (resting potential)
- This is done via leak channels or Na-K pump.
Leak channels or ion channels
- Passive channels that are always open that allows sodium and potassium to move through the membrane to reach equilibrium.
- Potassium is the most influential to keep -70mV
Na-K pumps
- Active transport of ions across a membrane (3Na, 2K)
- Transport protien.
Graded potentials
- Travel over short distances and are activated by the opening of mechanically or chemically gated channels.
- They occur in the cell body and dendrites of the neuron.
- Strength is proportional to the strength of the triggering event.
EPSP
- Graded potential depolarization called excitatory postsynaptic potential.
IPSP
- A graded potential hyperpolarization is called inhibitory postsynaptic potentials.
Action potentials
- Travel over long distances and they are generated by the opening of voltage gated channels
- Rapid sequence of changes in the voltage across a membrane.
What are the variety of stimuli that gated ion channels in the membrane are open to?
- Mechanical forces: Sensory neurons.
- Chemical ligands: Neurotransmitters (acetocholine)
- Voltage: Changes in the resting membrane potential.
Threshold voltage/trigger
- Point of no return.
- A graded potential travels through the neuron until they reach the trigger zone. If they depolarize the membrane above threshold voltage, an action potential is triggered and travels down the axon.
How does action potential move faster?
- By jumping over myelin and depolarizing at the Nodes of Ranvier.
Where is the synapse located?
On the dendrites of another neuron.
What are the Nodes of Ranvier?
- Parts of the axon not covered by myelin.
What is a synapse?
- Where neuron to neuron communication happens.
- Postsynaptic current causes excitatory or inhibitory postsynaptic potential that changes the excitability of the postsynaptic cell.
What 4 structures most directly involved in the control of voluntary movement?
- Cerebrum
- Diencephalon
- Cerebellum
- Brainstem
Cerebrum anatomy
- Left and right, connected by the corpus callosum
- Covered by cerebral cortex
- gray tissue, 2 to 5 mm thick
Ridges
- Each is called a gyrus
Grooves
- Each is called a sulcus
4 lobes of the cerebral cortex
- Frontal
- Parietal
- Occipital
- Temporal
Frontal Lobe function
- Control of voluntary movements
Parietal lobe function
- Control of perception of sensory information
Occipital lobe function
- Control visual perception
Temporal
- Control memory, abstract thought and judgment.
Motor cortex function and location?
- Location: Frontal lobe, just anterior to central sulcus.
- Function: Initiation and coordination of movements for fine motor skills.
Sensory Cortex function and location?
- Location: Posterior to central sulcus.
- Function: Receives axons specific to type of sensory information.
Cerebral Cortex-Premotor area location and function.
- Location: Anterior to the primary motor cortex
- Function: Organization of movement, rhythmic coordination, learning from others
Cerebral cortex-Supplementary motor area function and location
- Location: Medial surface of frontal lobe adjacent to portions of the primary motor cortex.
- Function: Sequential movements, preparation and organization of movement.
Basal ganglia
- Motor Control
