0
Neurophysiology
A branch of neuroscience that studies the physiology of the nervous system. From the Greek words nerve and nature, this science looks at the way that nerves function.
321 Questions
I believe it's Na+
There are several types of synapses in the body. The most commonly discussed type is the chemical synapse, but other types of synapses include electrical synapses and immunological synapses. Because chemical synapses are the most commonly discussed synapses in general, that's probably what this question is referring to.
A chemical synapse is a small gap, or commonly referred to as a connection, between two cells that allows for the first cell (the presynaptic cell) to communicate with the second cell (the postsynaptic cell) through a chemical signal. These chemical signals are called neurotransmitters, and once they are released by the presynaptic cell, they act on the postsynaptic cell through specialized protein molecules called neurotransmitter receptors.
The actions triggered by a neurotransmitter binding its receptor on the postsynaptic cell are highly varied. They vary according to the type, quantity, and frequency of neurotransmitter release, the specific receptor involved, the type of cell that is receiving the neurotransmitter signal, among other things. For example, a neurotransmitter called glutamate typically causes activation of the postsynaptic cell, while a neurotransmitter called GABA typically inhibits postsynaptic cells. Likewise, if the postsynaptic cell belongs to a gland, then activity in that cell may promote secretion, while inhibition may hinder secretion. If the postsynaptic cell is a muscle fiber, then activation triggers muscle contraction, while inhibition causes relaxation.
A synapse is a connection which allows for the transmission of nerve impulses. Synapses can be found at the points where nerve cells meet other nerve cells, and where nerve cells interface with glandular and muscular cells. In all cases, this connection allows for the one-way movement of data. The human body contains trillions of synapses, and at any given time, huge numbers of these connections are active.
What is a neurotransmitter and where is it located?
Neurotransmitters are molecules that travel from the synapses of one neuron to the dendrites of another neuron, activating channels on the second neuron that allow an influx of ions to rush in and start an impulse within the second neuron.
A rather generic term which means you have irritation/inflamation of one or more of the nerves that exit from your neck vertebrae. It is Not a ruptured cervical disc but it may give you symptoms that are similar in nature..but your MRI is probably negative for a herniated or ruptured disc..so they call it cervical neuritis.
When do you use relative refractory period?
The relative refractory period is the time during which the generation of an action potential is impossible no matter the strength of the stimulus
What is the harmful effect of genetic engineering?
Well, the bad is that it's a fairly new area, and people aren't really certain about what might happen in the long run from what they do. Something that looks good to start with might end up doing a lot of damage.
Brain areas involved in hunger and thirst?
You may think that hunger is all in your stomach and that dieting is all in your head. But nutrition experts know that hunger is regulated by a complex system of chemicals that send signals between your brain and your body.
The cells in the hypothalamus communicate with cells in other parts of the brain to coordinate the release and uptake of chemicals that help regulate how much and what you eat. Food triggers the brain to turn the desire to eat into the act of eating. How a food smells, what it looks like, and how you remember it tasting excite chemicals within your brain.
The breakdown products of foods - amino acids from protein, fatty acids from fat, and glucose fromcarbohydrates- regulate hormones such as insulin, which affect the process at a cellular level. They send messages to the brain telling it that fuel is needed.
When the body needs nourishment, neurotransmitters are released. One neurotransmitter called Neuropeptide Y (NPY) is important in sending messages to various parts of the brain.
Scientists have recently identified two chemicals - ghrelin and leptin - circulating in the blood that communicate with NPY.
Ghrelin and glucose: According to the theory, low levels of glycogen and low blood sugar levels stimulate a spike in ghrelin and NPY's activity in the hypothalamus. As NPY is stimulated, your desire for sweet and starchy foods goes up. And when ghrelin rises, so does appetite.
While you sleep, your glycogen and blood sugar stores are used up, causing the brain to release NPY. Skipping breakfast increases NPY levels so that by afternoon, you're set up for a carbohydrate binge. This craving for carbs is not the result of a lack of willpower; it's an innate biological urge at work.
The leptin link: After eating, leptin levels increase and inhibit the firing of NPY, so you feel full. If it has been a while since you've eaten, your blood levels of glucose are low and therefore leptin is low, and ghrelin is high.
The circulating levels of ghrelin peak at different times depending on when you have your heaviest meal. People who eat big lunches show ghrelin peaks at a different time than people whose main meal is at night.
In addition, these processes are at work:
The galanin-fat connection: Galanin is released when fat stores need filling up. In the evening, galanin levels tend to rise, which may be nature's way of making sure that people have enoughcaloriesto last them through the night.
CCK: When you eat, food enters and fills your stomach and then travels to the intestinal tract. As the food is digested and the body's cells are fed, a chemical called cholecystokinin (CCK) is released, turning on feelings of fullness and turning off the appetite.
Researchers think that certain conditions, such as anorexia and bulimia, may affect many appetite-control body chemicals, including CCK. In bulimics, researchers think that either the CCK mechanism doesn't work properly or the body's chemical systems become so desensitized that the person eats huge quantities of food quicker than the brain is able to signal satisfaction and fullness.
The opposite effect may occur in anorexics - the CCK mechanism is so oversensitized that they feel full after only a few bites of food. When bulimics and anorexics start eating normally, their CCK systems usually normalize.
What is reptilian cephalization?
Reptilian cephalization refers to the development of a more advanced and specialized head region in reptiles. This includes features such as a larger brain, sensory organs like eyes and nostrils, and specialized structures for feeding and communication. Cephalization allows reptiles to exhibit more complex behaviors and adapt to different ecological niches.
What can make your tongue twist?
Factors such as rapid speech, unfamiliar sounds, accents, tongue twisters, or physical conditions like a tongue tie or neurological disorders can make your tongue twist while speaking. Additionally, factors like stress, nerves, or fatigue can also contribute to tongue twisting.
Why is the amygdala important?
It is a roughly almond-shaped mass of grey matter inside each cerebral hemisphere, involved with the experiencing of emotions. The amygdala is a section of the brain that is responsible for detecting fear and preparing for emergency events.
How many neurons does the cerebellum have?
How many neurons does the cerebellum have?
This is an interesting question. Of the sources I have reviewed thus far, I have not found a consistent approximation of neurons in the cerebellum.
The human brain has (estimate) 100 billion neurons. Some sources say 10-100 billion. According to Wikipedia, the cerebellum takes up 10% of the brain's total volume and contains roughly 50% of all the neurons in the brain. In that case, 50 billion neurons in the cerebellum.
However, in the book I'm currently reading, it has suggested that the cerebellum neuron count is more like 70 billion. Therefore, the cerebrum (rest of the brain) has the remaining 30%.
Interesting isn't it? Such a small structure contains majority of the brain's neurons. Additionally, the cerebellum has Purkinje cells, which are among the largest neurons in the brain. According to Wikipedia, Granule cells (very tiny neurons) are very numerous in the cerebellum which are accountable for the mass % of neurons in this particular cortex.
Hope I have helped you! However, take note that to some people Wikipedia is not a valid source. To me it's reliable in some circumstances. The book I'm reading now was written by an M.D so I feel that is more reliable, so I'll go ahead and say that the cerebellum has (estimate) 60-70 billion neurons.
What are the neurophysiological process?
The processes pertaining to the functions of the nervous system of an organism. http://www.genomeknowledge.org/cgi-bin/eventbrowser?DB=gk_current&FOCUS_SPECIES=Homo%20sapiens&ID=160046&
How do livng things respond to stimuli?
There are two types of responses to stimuli. 1)Deep response which requires integration by the brain such as thinking. 2)Simple response which is done by reflex arc. The reflex Arc is consisted if receptor, sensory neuron, relay neuron, motor neuron and effector which is either muscle or gland.
For example in humans. If your hand touches a hot object.
Heat receptors in your hand will act as sensor, passing an impulse by generating action potential in the sensory neuron. The sensory neuron passes the impulse to along it till reaching the spinal cord passing the impulse to the relay neuron by a process called synapse. The relay neuron synapse with motor neuron to pass the impulse to it. The end of the motor neuron is connected to the bi-ceps muscle in the arm. As the impulse reaches the end of the motor neuron it passes impulse to the muscle ordering it to contract, thus the hand is removed away from stimulus. This process take a fraction of a second.
How is cerebral-spinal fluid formed?
It is formed by filtration of blood through the fenestrations of the choroidal capillaries in the choroid plexus. It is flows by the active transport of substances (Particularly sodium ions) across the choroid epithelium into the ventricle, water then flows passively across to maintain osmotic balance.
It has also been shown that if the choroid plexus was removed the ventricles still produced substantial quantities of CSF, though less than normal. And is generally considered to be fluid movement from CNS capillaries into the parenchyma of the brain, and from there across the ependymal lining into the ventricle.
What is the problem with nudity?
The problem with nudity is often rooted in societal norms and expectations around modesty and privacy. Different cultures and communities have varying views on nudity, with some considering it taboo or inappropriate in certain contexts. Additionally, there may be concerns around exploitation, objectification, and consent when it comes to the public display of nudity.
Where can a neuron be stimulated?
The cell membrane becomes more permeable to the sodium potassium ions.
How are stimuli converted into signals for the body to respond to?
stimuli are converted into electronic signals. Such electronic signals travel by a huge network of nerves throughout the body. These signals converge to the brain, where sensory neurons interpret them and send back an "order" through the Central Nervous System, to the correspondent point of the body where the stimulus has happened. Such "order" may refer to the release of defence cells, or simply tell your arm to touch the point of the stimulus,in order to calm you down, as a simple example. The signal that flows through the nerve, uses a mineral, magnesium, as a basis to conduct the electronic signal. Sodium is another mineral that participates of the process. Such travel may take only miliseconds to reach the brain and to come back.
What receives stimuli and forms impulses?
Neurons receive stimuli from the environment or other cells, which triggers the formation of electrical impulses that travel along the neuron's axon. These impulses then allow for communication between different parts of the body or with other neurons.
Not electronically. Brain activity can be recorded but it gives no indication of the content of a dream
What is the Most common variation of the circle of Willis?
The proximal part of the posterior cerebral artery is narrow and its ipsilateral posterior communicating artery is large, so the internal carotid artery supplies the posterior cerebrum.
What is the sequence of events that follow a threshold potential?
Following a threshold potential, voltage-gated sodium channels open, allowing sodium ions to rush into the cell, depolarizing the membrane. This triggers an action potential that spreads down the length of the neuron. Once the action potential reaches the end of the neuron, it triggers the release of neurotransmitters into the synaptic cleft to communicate with the next neuron.
What is the importance of the arterial anastomoses?
they form alternate pathways for blood to reach a given body region
