Introduction to neurons and glia. How the structure of a neuron allows it to receive and transmit information.
Log in Nafees Iqbal 8 years agoPosted 8 years ago. Direct link to Nafees Iqbal's post “What exactly occurs durin...” What exactly occurs during a reflex arc? • (11 votes) Barbara Gonzalez Busta 8 years agoPosted 8 years ago. Direct link to Barbara Gonzalez Busta's post “A reflex "arC" is not a s...” A reflex "arC" is not a series of actions but the structure that allows a reflex "acT" to happen, and it comprises (in a sequential order) a stimulus, a receptor, an afferent pathway, a synapse, an efferent pathway, an effector and a response. (29 votes) Tim Wegmann 8 years agoPosted 8 years ago. Direct link to Tim Wegmann's post “Why do we need interneuro...” Why do we need interneurons? Wouldn't a direct connection between motor and sensory neurons be faster? • (7 votes) Jack O' Light 7 years agoPosted 7 years ago. Direct link to Jack O' Light's post “Interneurons also integra...” Interneurons also integrate signals, thus "determining" an appropriate response. (10 votes) kakarorahahai 6 years agoPosted 6 years ago. Direct link to kakarorahahai's post “Is it possible that the d...” Is it possible that the dendrites on the cell body receives strong impulses of more than one type.In such a case how are all transmitted simultaneously? • (7 votes) Ivana - Science trainee 5 years agoPosted 5 years ago. Direct link to Ivana - Science trainee's post “GOOD QUESTIONThat is tr...” GOOD QUESTION That is true and that is called synapse. Dendrites convert these signals into small electric impulses and transmit them inward, in the direction of the cell body. Neuronal cell bodies can also form synapses and thus receive signals (Figure 21-3). Particularly in the central nervous system, neurons have extremely long dendrites with complex branches. This allows them to form synapses with and receive signals from a large number of other neurons (1000). (4 votes) kira 6 years agoPosted 6 years ago. Direct link to kira's post “What is the purpose of ha...” What is the purpose of having different types of neuron structures? • (4 votes) Lara 6 years agoPosted 6 years ago. Direct link to Lara's post “Different neuron structur...” Different neuron structures change the way the signal is treated and conducted. Imagine a big tree. You are sitting in the area where all the branches come together and the trunk starts, this could be the same as the soma of a neuron since all dendrites come together. A friend of yours is sitting on the grass next to the trees roots (which is the terminals in the neuron analogy). Think of the signal as a ball that you want to give your friend; you let it fall. If the trunk is long, then it will take longer for your friend to catch the ball, if the trunk is short, you might even be able to give it personally to your friend. So the axon is responsible for the temporal delay of the signal conductance, similarily to the dendrite. If the dendrites are long, it takes longer until they reach the soma. Therefore, weak signals will maybe not even arrive at the soma since they decay with time. Additionally, a huge dendritic tree means that it has a lot of potential for many many connections to other neurons. Therefore, for instance the Purkinje cell with its huge dendrical tree acts as an integrator of many different signals. (7 votes) Sonakshi 8 years agoPosted 8 years ago. Direct link to Sonakshi's post “Human brain consist of ce...” Human brain consist of cerebral cortex as its outermost layer below cranium . Does human beings have the capacity to use all areas of cerebral cortex or only few designated areas?? • (2 votes) myopicvisions 8 years agoPosted 8 years ago. Direct link to myopicvisions's post “interestingly enough, so-...” interestingly enough, so-called idiot savants, do not have a greater capacity for computation, music, or art. Instead, the parts of their brains responsible for such tasks dominate the rest of their brain because the parts that would normally compete for attention are either damaged or unable to communicate effectively with the rest of the brain. Researchers have used something called TMS (trans-cranial magnetic stimulation) to induce small currents in parts of the brain, either shutting down or activating specific regions of the brain temporarily. Their research has shown that it is possible to temporarily induce a savant-like state in normally functioning brains. And, of course, some forms of brain damage can induce temporary or permanent savant-like states as well. I met a young man who had the ability to perform amazing feats of computation after a bad car accident. (7 votes) ankit.javadev 8 years agoPosted 8 years ago. Direct link to ankit.javadev's post “What are mirror neurons a...” What are mirror neurons and are these present in humans also? • (3 votes) Ivana - Science trainee 5 years agoPosted 5 years ago. Direct link to Ivana - Science trainee's post “mirror neurons respond to...” mirror neurons respond to actions that we observe in others. The interesting part is that mirror neurons fire in the same way when we recreate that action ourselves. Apart from imitation, they are responsible for a myriad of other sophisticated human behavior and thought processes. And yes, they are present in humans. :D (1 vote) yinqin09 a year agoPosted a year ago. Direct link to yinqin09's post “is there relay neuron in ...” is there relay neuron in this section • (2 votes) ibsatit a year agoPosted a year ago. Direct link to ibsatit's post “its an interneuron in thi...” its an interneuron in this context (2 votes) Potatosalad021 3 years agoPosted 3 years ago. Direct link to Potatosalad021's post “How the neurons sense our...” How the neurons sense our taste and other stuff? sorry if the question is bad :P • (2 votes) Natrium Chloride 3 years agoPosted 3 years ago. Direct link to Natrium Chloride's post “When eating, the taste re...” When eating, the taste receptor cells in our taste buds detect concentrations of different chemicals and fire electric signals to sensory neurons, which in turn fire a nerve impulse to the brain. That said, it is not the neuron that senses the taste, but the taste receptor cell. The neuron is the one that transfers the message (nerve impulse) to the brain. In the same way, the cell that senses the stimuli in any part of the body is the receptor, not the neuron. So about taste sensation, the stimuli is actually the chemicals in our mouth. When the pH is low, we feel that it's sour. When the pH is high, we feel that it's bitter. When there is sugar, we feel that it's sweet. When there is salt, we feel that it's salty. And certain proteins cause the taste of unami. When it comes to taste, it's actually the concentration of different substances that cause the senses. (pH is the concentration of H+ ions) And no worries, your question isn't bad. If a question helps you learn, it's not bad. Even if we ask bad questions every now and then, there's nothing wrong with that either. (3 votes) Sindhu Gunturi 8 years agoPosted 8 years ago. Direct link to Sindhu Gunturi's post “The word "active potentia...” The word "active potential" is mentioned many times. What does it mean? • (0 votes) Justin Cabezas 8 years agoPosted 8 years ago. Direct link to Justin Cabezas's post “Action potential is a sho...” Action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. (6 votes) megarn.melling 7 years agoPosted 7 years ago. Direct link to megarn.melling's post “In the axon of someone wi...” In the axon of someone with Multiple sclerosis what happens to the myelin sheath and nodes of ranvier? I know that the myelin sheath is not there so it slows down the action potential, but I would like a bit more in depth explanation. thanks • (2 votes) Ivana - Science trainee 5 years agoPosted 5 years ago. Direct link to Ivana - Science trainee's post “Multiple sclerosis (MS) i...” Multiple sclerosis (MS) is the most common demyelinating and an autoimmune disease of the central nervous system characterized by immune-mediated myelin and axonal damage, and chronic axonal loss attributable to the absence of myelin sheaths. with concomitant degradation of myelin, oligodendrocytes and axons, along with reactive astrogliosis and activated microglia - meaning that there is no only the problem of demzeliniyation but of hzperactive microglia. additional T-cell subsets play a prominent role in MS immunopathology: Th17 cells, CD8+ effector T cells and CD4+CD25+ regulatory T cells. There are different mechanisms for lipid antigen uptake depending upon the antigen source and its structure such that endogenous lipids are differentially distributed in subcellular compartments and internalized lipids are transported to different endocytotic vesicles. Demyelinated plaques and associated astrocytic activation (gliosis) are the results of local inflammation and the major pathological characteristics of the disease. (2 votes)Want to join the conversation?
The reflex "acT" is an involuntary response to a stimulus, where the components I just mentioned interact. So what happens is the following:
1) A stimulus activates a receptor.
2) The receptor transmits the signal to an afferent pathway.
3) The afferent pathway carries the signal to a place (e.g. spinal cord) where this pathway synapses (or communicates with) the efferent pathway.
4) The efferent pathway carries a signal to an effector (e.g. muscle)
5) The effector executes a response (e.g. muscle contraction)
So basically each anatomical structure has different functions to offer.
Lipids containing alkyl chains that have multiple unsaturation sites or shorter saturated tails are trafficked to early or recycling endosomes [62]; compartments surveyed by CD1c and CD1a that present these types of lipids.
