Nerves

it takes time to reach its mechanism.

Neurons are nerve cells. Neurons in the brain are involved in thinking and perceiving and consciousness and control of the body, and neurons elsewhere in the body communicate with the brain.

1. An Optic Tract is the pathway between the optic chiasma and the brain.

when you touch a hot stove you feel pain in your hand. Your hand feels the pain and sends a message of pain to the brain. The brain sends a message to stop before any more damage is done

The Optic Nerve (one of the Cranial Nerves) is enclosed by three sheaths that are continuous with the three layers of cranial meninges (dura, arachnoid, and pia). The central artery and vein of the retina pass through these meningeal sheaths and are included in the distal part of the optic nerve.

1. Nerve impulse reaches synaptic terminal.

2. Synaptic vesicles move to and merge with the presynaptic cell membrane of the motor neuron.

3. Acetylcholine is released into and diffuses across the synaptic cleft.

4. Acetylcholine binds to receptors on the postsynaptic cell membrane of the muscle fiber.

Synapses are junctions that allow a neuron to electrically or chemically transmit a signal to another cell. Synapses can either be excitatory or inhibitory. Inhibitory synapses decrease the likelihood of the firing action potential of a cell while excitatory synapses increase its likelihood. Excitatory synapses cause a positive action potential in neurons and cells.

For example, in the neurotransmitter Acetylcholine (Ach), its binding to receptors opens up sodium channels and allows an influx of Na+ ions and reduces membrane potential which is referred to as Excitatory Postsynaptic potential(EPSP). An action potential is generated when the polarization of the postsynaptic membrane reaches threshold.

ACh acts on nicotinic receptors which can be found at the neuromuscular junction of skeletal muscles, the parasympathetic nervous system, and the brain. It also acts on muscarinic receptors found at neuromuscular junctions of the smooth muscles, glands, and the sympathetic nervous system.

Inhibitory synapses, on the other hand, cause the neurotransmitters in the postsynaptic membrane to depolarize. An example is the neurotransmitter Gamma Aminobutyric Acid (GABA). The binding of GABA to receptors increases the flow of chloride (CI-) ions in the postsynaptic cells raising its membrane potential and inhibiting it. The binding of GABA to receptors activates a second messenger opening potassium channels.

first through the back of the brain than to other parts of your body.

its a measurement of electric energy used to power things like:

houses, busynesses and other buildings

The touch receptors are grouped by type and include Mechanoreceptors (sensitive to pressure, vibration and slip), Thermoreceptors (sensitive to changes in temperature), and Nocioreceptors (responsible for pain).

Because your sensory nerve endings became adapted to it with time.

These are typically known as neuromodulators; they can either change the rate at which a neurotransmitter is released, or alter the response to a certain neurotransmitters.

can siatic nerve cause numbness and pain in calf

An interneuron (also called relay neuron, association neuron, connector neuron or local circuit neuron) is a neuron that forms a connection between other neurons. Interneurons are neither motor nor sensory.

I found this page to be helpful.

http://gme.chm.msu.edu/musclenervedb.htm

It tells where each root nerve goes and what it does.

myelin sheath

neurotransmitter

The place were neurons transfer an impulse to another structure is called a synapses. This is actually a gap between these 2 structures and the impulse has to cover that.

The initial segment of a neuron, also known as the axon hillock, is crucial for the generation of action potentials. It integrates incoming signals from the dendrites and cell body, determining whether the combined input is strong enough to trigger an action potential. This segment has a high concentration of voltage-gated sodium channels, which facilitate the rapid depolarization necessary for the propagation of electrical signals along the axon. Essentially, it serves as the "decision point" for neuronal firing.

The tenth cranial nerve is called vagus nerve it is also called as wandering nerve.It has been called wandering nerve because of many areas it innervates. the vagus nerve wanders all the way down from the brainstem to the colon, a long wandering trek.

D. All of the choices are correct.

A nerve cell, or neuron, is long and branching.