Neuroscience

No, the parasympathetic nervous system is often referred to as the resting and digesting system, as it controls functions like digestion, relaxation, and energy conservation. The sympathetic nervous system is responsible for the "fight or flight" response, activating the body in times of stress or danger.

There are actually two enzymes that breakdown dopamine:

1) MAO-B (monoamine oxidase B)

2) COMT (carboxy-O-methyltransferase)

A motor unit consists of a somatic motor neuron and all the skeletal muscle fibers it innervates. When the motor neuron fires an action potential, all the muscle fibers in its motor unit contract simultaneously. Motor units vary in size depending on the precision of movement required, with smaller units needed for fine control and larger units for more powerful movements.

Generally you can think of sympathetic stimulus causing contraction of smooth muscle with a few exceptions (bronchial dilation).

One activity would be the acute modulation of blood pressure through contraction of vascular smooth muscle cells in the resistance vessels.

While there is some debate, sympathetics probably set the steady state heart rate with very little acute control. Acute modulation of heart rate is caused by parasympathetic stimulus and mechanical factors (Frank-Starling relationship).

Sympathetics also aid in the mobilization of metabolic energy (lipolysis, glycogenolysis).

Look in any physiology textbook for autonomic nervous system and you can get all your answers.

There are several factors that can prevent a neuron from firing an action potential, such as insufficient depolarization of the cell membrane, inactivation of voltage-gated sodium channels, inadequate synaptic input, or the presence of inhibitory neurotransmitters. Additionally, factors like refractory periods and external influences such as drugs or toxins can also prevent an action potential.

The sympathetic nervous system is the part of the autonomic nervous system originating in the thoracic and lumbar regions of the spinal cord that in general inhibits or opposes the physiological effects of the parasympathetic nervous system, as in tending to reduce digestive secretions, speeding up the heart, and contracting blood vessels.

After discontinuing a dopamine receptor blocker, the extra dopamine receptors may eventually return to their normal levels through a process called receptor downregulation, where the body reduces the number of receptors due to decreased demand. This process helps restore balance to the dopamine system.

Neurotransmitters are chemicals released by neurons that carry signals across the synapse to stimulate the next neuron in the chain. They play a crucial role in influencing action potential propagation by either triggering or inhibiting the generation of new action potentials in the postsynaptic neuron. This process helps in the transmission of nerve signals through the nervous system.

Neurons do not fire action potentials because they are not excitable cells like nerve cells. Neurons are made up of a cell body, dendrites, and an axon that transmit signals in the form of electrical impulses, known as action potentials.

In waterlily cells, the function of the vacuole is to store nutrients, water, and waste products. In fish cells, the function of the mitochondria is to produce energy in the form of ATP through cellular respiration. In paramecium cells, the function of the contractile vacuole is to regulate water content by pumping out excess water to maintain internal osmotic balance.

Neurontin (gabapentin) is not typically associated with causing seizures, even if not taken with acetaminophen. In fact, Neurontin is commonly used to treat seizures as well as nerve pain. It is important to always take Neurontin as prescribed by your healthcare provider.

The inside of a hyphae is typically filled with cytoplasm and numerous organelles that are responsible for nutrient uptake and growth. It also contains a central vacuole that helps with maintaining cell turgor pressure and storage of nutrients. Additionally, the cell wall of hyphae is made up of chitin or cellulose, providing structural support and protection for the fungal cell.

The sympathetic nervous system is one of three major parts of the autonomic system. The autonomic nervous system (ANS) is the part of the nervous system that controls most of the things we don't do voluntarily. Things such as heart rate, respiratory rate, sexual arousal and tone of the muscle inside your eye (the iris).

The sympathetic part of the ANS is often considered to promote a "fight or flight response" while the parasympathetic part does the opposite ("rest and digest"). If we think about a dangerous situation where you want to have a "fight or flight response", you generally want to have more light entering your eyes so that you have a heightened visual sense. This is accomplished when your sympathetic nervous system activates the radial muscles of your iris. In contrast, your constricter muscles are relaxed. This leads to dilated pupils forming part of the sympathetic response.

If a neuron was stimulated simultaneously at both ends, the action potential generated in the middle would effectively cancel out due to the opposing electrical currents flowing towards each other. This phenomenon is known as antidromic collision and may prevent the neuron from conducting signals efficiently.

they would react to it

An action potential does not have a conduction velocity. Rather, it makes sense to measure the conduction velocity of nerves or nerve cells and this is usually done in metres per second (m/s.).

An action potential is characterised as "an all or none response". This means you cannot alter the characteristics of an action potential in a given nerve cell. If you get a nerve cell and manage to get it to threshold, produce and measure an action potential 1000 times or more at the exact same point on the cell, the action potential you measure will not change in timing or amplitude.

Information travels down a nerve cell through action potentials. But it is not one action potential that travels the whole length of the axon. Instead what happens is that one action potential causes the next bit of the nerve cell to reach threshold and therefore creates an entirely new action potential. So you actually need multiple action potentials to happen along a nerve cell to send information down it. We call this "propagation of action potentials" since each action potential produces a new one. More properly, it is referred to as "saltatory action potential conduction".

Conduction velocity is basically a measure of how quickly we can produce a series of action potentials to travel the distance of the nerve cell axon. Since action potentials only happen at each "Node of Ranvier", then the longer the distance between each node (internodal distance), the faster the conduction velocity of a nerve cell. Since the internodal distance is positively correlated with myelin thickness, more thickly myelinated nerve cells have faster conduction velocities. The thickest and fastest nerve cells are motor neurones and Ia fibres from muscle spindles with a diameter of 12-20 micrometres and a conduction velocity of 70-120 m/s. The thinnest/slowest are fibres used to convey slow pain (<1.5 micrometres and 0.5-2 m/s).

Immature precursors that give birth to new specialized cells in the body are called stem cells. Stem cells have the ability to self-renew and differentiate into various types of cells, depending on the signals they receive from their environment. They are crucial for tissue repair, regeneration, and normal development.

Myelinated axons with a larger diameter will conduct action potentials the fastest due to saltatory conduction, where the action potential jumps from one node of Ranvier to the next, skipping the myelin-covered regions. Smaller-diameter and unmyelinated axons will conduct action potentials more slowly.

== == The nervous system of a wolf works just like that of a dog, and almost identical to yours. He doesn't have as large a neocortex as yours, especially the frontal lobes (presumedly for planning future actions), but on the other hand his sense of smell is several thousand times better than yours.

The resting membrane potential value for sodium is closer to the equilibrium of potassium because the sodium-potassium pump actively maintains a higher concentration of potassium inside the cell and a higher concentration of sodium outside the cell. This leads to a higher permeability of potassium ions at rest, resulting in the resting membrane potential being closer to the equilibrium potential of potassium.

Contributions are replacing broken bones in which builds blood vessels, cell by cell

1. Scientist coats the mucle of a tube of plastic scaffolding with muscle cells.

2. Scientist places the tube in nutrient-rich liquid which washes over and through the tube in gentle waves.

3. After eight weeks, the muscle cells have broken down the plastic scaffolding and they begin replacing it with connective tissue.

4. Scientist paints the inside of the tube with skin cells. A blood vessel has been built, cell by cell.

Yes, Lyrica (pregabalin) has been associated with an increased risk of seizures, particularly in individuals with a history of seizure disorders. It is important for individuals starting Lyrica to discuss their medical history with their healthcare provider to assess this risk and to monitor for any signs of seizure activity during treatment.

No, action potentials are all-or-nothing events that either reach their full potential or do not occur at all. Once the threshold is met, the action potential will propagate along the neuron without diminishing in strength.

Potential triggers for behaviors of concern can include stress, changes in routine, sensory overload, communication difficulties, physical discomfort or pain, and feeling overwhelmed or frustrated. Identifying and understanding these triggers can help in managing and addressing the behaviors effectively.

A hemangioma is a benign tumor comprised of blood vessels, usually in a cluster formation, similar to a rasberry. Lipo refers to fat, so this is a combined fatty, vascular growth. Main problem with these tumors is that the blood vessels can rupture, causing bleeding. They may cause no symptoms, or if large, may cause symptoms such as pain from pressure on surrounding organs. Symptoms depend primarily on location and size. They can be external or internal.