Neuroscience

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The regeneration of action potential is called "propagation." It involves the transmission of the action potential along the length of the neuron's axon.

To keep your nervous system healthy, it's important to maintain a balanced diet rich in fruits, vegetables, whole grains, and lean proteins. Regular physical exercise, sufficient sleep, stress management techniques, and avoiding habits like smoking and excessive alcohol consumption also contribute to nervous system health. Additionally, staying hydrated, managing chronic conditions like diabetes, and protecting yourself from head injuries can help support overall nerve function.

When an action potential reaches the end of a neuron (presynaptic neuron), it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the next neuron (postsynaptic neuron), causing ion channels to open and generate a new action potential. This communication process allows signals to be transmitted from one neuron to another.

An example of a non-antagonistic interaction of the sympathetic nervous system is when it triggers the "fight or flight" response in response to a perceived threat. This response involves simultaneous activation of multiple physiological processes such as increased heart rate, dilated pupils, and release of adrenaline to help the individual respond to the threat effectively.

Repolarization is the phase in which the cell membrane potential returns to its resting state after depolarization. This is driven by the efflux of potassium ions, resulting in the membrane potential becoming more negative. Repolarization is essential for the heart to reset and prepare for the next action potential.

Sensory neurons have one axon to transmit signals from the peripheral nervous system to the central nervous system. This allows for the efficient relay of sensory information such as touch, pain, and temperature to the brain for processing. Having one axon helps maintain the specificity and accuracy of the sensory signals being conveyed.

The outer nervous system consists of the somatic nervous system and the autonomic nervous system. The somatic nervous system controls voluntary movements and receives sensory information. The autonomic nervous system regulates involuntary functions like heart rate, digestion, and breathing.

Motor neuron endings are specialized structures at the terminal ends of motor neurons that form synapses with muscle fibers. These endings release neurotransmitters, such as acetylcholine, to stimulate muscle contractions. They play a crucial role in transmitting signals from the nervous system to muscles, allowing for voluntary movement.

No. The inside of the neuron becomes more positively charged.

The resting potential is -70 millivolts. So, the outside of the neuron starts off being more positively-charged, and the inside is more negatively-charged.

As sodium ions (which are cations - positively-charged ions) move into the neuron (via sodium ion channels), this depolarizes the neuron (induces a "signal"). If this net signal is above a certain threshold, it will trigger an action potential, whereby channels will open in the axon, just ahead of the action potential itself, which allows more cations to flow into the axon, increasing the positive charge inside the axon, and further triggering the opening of cation channels downstream.

Note: As the action potential (positively-charged region inside an axon) propagates down the axon, sodium channels open behind it to pump sodium ions back outside the axon, restoring the inner negative charge of that region, so that it can return to the resting potential. Therefore, once the action potential is formed inside the axon, and is moving downstream, sodium pumps open behind it so that the signal is dampened in an already-activated region, thereby restoring the resting potential. This prevents retriggering a secondary action potential (which would result in amplification of the end signal).

On the other hand, when an inhibitory neurotransmitter binds with the neuron, or else a chloride ion channel (chloride ions are anionic - negatively-charged) opens, chloride ions enter the neuron, which drives the membrane potential further into the negative, thereby reducing the likelihood of action potential (signal) generation.

No. The sympathetic nervous system is excitatory. It works via epinephrine and norepinephrine to put the body on a state of alert, vigilance, and action.

The parasympathetic nervous system (controlled mainly by acetylcholine) is relaxing and calming.

When you accidentally drop a ballpen, sensors in the skin and muscles of your hand detect the tactile sensation and send signals through nerves to the spinal cord. The spinal cord then relays this information to the brain, which quickly processes it and sends commands back to the muscles to pick up the ballpen. This process happens rapidly and automatically, allowing you to react and retrieve the ballpen without much conscious effort.

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The axon is the structure in the neuron that sends signals to other neurons or organs. It transmits electrical impulses away from the cell body towards the target cells, allowing for communication within the nervous system.

A false statement about a cell's resting membrane potential could be that it does not involve the movement of ions across the cell membrane. In reality, the resting membrane potential is primarily due to the unequal distribution of ions, such as sodium and potassium, across the membrane, maintained by ion channels and pumps.

An aura is a sensation that can happen before a seizure, often acting as a warning to the person that they are about to have one. Different people experience different things. It could be a feeling, like a tension or fear or nervousness. It could be a physical sensation, maybe a feeling in their mouth or their stomach or a tingling around their body. It could be a sensory perception or a feeling of confusion. Any of these and other things can be called an aura.

It can be a warning of a seizure coming, but it is like a mini-seizure in itself and sometimes nothing else happens after it. To explain that aspect to someone who has never had a seizure you could refer to other kinds of experiences, like when you feel you are about to sneeze and then it doesn't happen. If they do have a seizure the aura may come immediately before the seizure or there may be a time delay of minutes or even as much as an hour before the seizure happens. A person will know they are having an aura and will remember that, though they will not remember a seizure itself. Although there are different kinds of auras any individual that gets auras will normally always have the same type of one. Auras can also happen for other conditions to do with the head, like migraines.

also known as the "nerve impulse". with stimulus the permeability of the membrane to NA+ at the point of stimulation increase, and NA- ions rush into the cell causing the outside to lose its excess of positive ions. That location becomes depolarized only for an instant, and this produces an action potential.

In muscle contraction and impulse conduction, important ions include calcium (Ca2+), sodium (Na+), and potassium (K+). Calcium plays a key role in triggering muscle contraction by binding to troponin, sodium influx starts the action potential at the synapse, while potassium efflux helps repolarize the membrane after the action potential passes.

Sodium ions flow into the neuron via voltage-gated sodium ion channels, driving the membrane potential into the positive. Beyond the threshold, more sodium ion channels are opened, causing the influx of sodium further downstream, and the process repeats, propagating the action potential down the axon.

When a resting neuron's membrane depolarizes, it becomes more positive due to an influx of positively charged ions like sodium. This change in membrane potential triggers an action potential, leading to the propagation of electrical signals along the neuron.

When an action potential reaches the axon terminal of the presynaptic neuron, it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the postsynaptic neuron, leading to changes in its membrane potential. This process either excites or inhibits the postsynaptic neuron, depending on the neurotransmitter and receptor type involved.

The dendrites of a neuron receive impulses from other neurons and transmit them to the cell body.

The brain generates efferent signals for the body.

Efferent signals travel down the spinal cord, and out to target areas of the body.

Afferent feedback signals travel back to the spinal cord, and back up to the brain for processing.

1. A neurotransmitter (NT) released from another cell (or in some cases the same cell) will diffuse across the synaptic cleft and bind to a recipient receptor.

2. The receptor will then change it's permeability to certain ions in the extracellular fluid, allowing the ions to flux into the cell (the exception here would be pharmacological agents designed to occupy the receptor without leading to a conformation change)

3. The influx of ions will alter the membrane potential. If the NT is inhibitory (e.g. GABA), then the GABA receptor that it binds to will increase its permeability to negatively charged ions (chloride) and thereby lower the local resting membrane potential (which is normally -70mV). If the NT is excitatory (e.g. glutamate) then the glutamte receptor (AMPA or NMDA) will increase its permeability to positively charged ions (sodium) which will increase the resting membrane potential from -70mV.

4. If enough NTs bind then the local membrane potentials will summate - and in the case of excitatory NTs - cause the membrane potential to change (by opening of voltage-gated ion channels) to around 0-20mV leading to an action potential

5. The action potential, which is generated in an 'all or none fashion' at the axon hillock, will then propagate all the way down the axon to the axon terminal causing the release of stored NTs (although not all NTs are stored - e.g. NOS)

6. NTs released from the presynaptic cell will then diffuse across the synaptic cleft and bind their postsynaptic receptor (normally located on a dendrite, although also located on the cell body themselves) and the whole process starts all over again

During repolarization, potassium channels open and potassium ions exit the cell, causing the inside of the cell to become more negative. This process restores the cell's resting membrane potential. It follows the depolarization phase, where sodium channels open and sodium enters the cell, causing the inside of the cell to become more positive.