Discussion in Context to Curriculum group: Reflex arc
[6:32 pm, 20/12/2024] Dinesh Datta : Let’s look at it like this…stepwise…
1.when we touch a hot stove,it activates pain receptors(nociceptors in the skin).
2.Heat activates what we call TRPV1,which is for heat,pain and inflammation.
3.This receptor activation causes rapid depolarization of nociceptor membrane and generates what we call ‘action potential’./I e voltage gated sodium channels open and Na+ rushes into the cell.
4.This action potential is propagated along the length of nociceptor axon to spinal cord.
5
[6:34 pm, 20/12/2024] Arunan Sir: Let’s understand the electrical energy transfers, in biological cells, like nerve cells or Neurons, as in sudden reflex of withdrawing hand from a hot object.
How do you try explaining the so called energy transfers, for example, while withdrawing hand in reflex action? @~Vickram Crishna @Dinesh Datta CUBE @Theertha @Enas
[6:36 pm, 20/12/2024] Arunan Sir: What is this depolarisation?
Depolarisation of what?
What was in a state of polarization?
[6:41 pm, 20/12/2024] Dinesh Datta : 5.action potential is generated and propagated due to rapid changes in membrane potential which is maintained by NaKatpase.This pump is powered by hydrolysis of atp.
6.action potential reaches to spinal cord and then to other neurons through synaptic transmission.
7.action potential causes release of neurotransmitters like glutamate and substance P in this case,from nerve terminal.
8.this neurotransmitters bind to postsynaptic neuron and cause postsynaptic potential.
9.this postsynaptic neuron activates motor neuron which sends signals to muscles of arm.
10.this causes muscle to contract and withdraw it from hot vessel.
11.This muscle contraction is due to acting myosin complex and similar NaKAtpase,hydrolysis,depolarization,action potential…Some differences
[6:42 pm, 20/12/2024] Dinesh Datta : That is resting membrane potential
[6:44 pm, 20/12/2024] Dinesh Datta : But management of burn injuries is different.
We have to evaluate degree of burns,Rule of 9(if anyone’s interested can check out),risk of dyselectromia,dehydration,infections
[6:47 pm, 20/12/2024] Dinesh Datta CUBE: Electric and chemical.
Electric as in movement of ions.Chemical as in release of neurotransmitters.
Mechanical in withdrawal of hand/muscle contraction,along with electrical and chemical
[6:51 pm, 20/12/2024] Arunan Sir: Let’s use simple language or with explanation of technical terms.
Surely, this is not an easy topic. @Dinesh Datta CUBE
Let’s take time and energy to simplify the explanation on how or how not nerve cells behave like electrical conductors.
Are they working like conducting wires that connect our switch to the bulb , to light up, or there is some subtle difference, since these are living cells with nucleus etc.? @~Vickram Crishna @Dinesh Datta CUBE @~Batul Pipewala @Enas @Theertha
[6:53 pm, 20/12/2024] +91 : 
very well summarized @Dinesh Datta CUBE
[6:54 pm, 20/12/2024] +91 : Do u mean time gap due to junctions between neurons?
[6:59 pm, 20/12/2024] Arunan Sir: Too many concepts in too short sentences using technical terms like depolarisation etc.
Let’s go slow and explain for all to understand the difficulty in comparing conduction of current through copper wire and that through Nerves Cells or Nerve.
For example, is there a difference between a Nerve Cell and a Nerve as we commonly understand?
Let’s try to resolve it and carry all readers together in our understanding. @Dinesh Datta CUBE Truly, a great opportunity.
@~Vickram Crishna Please raise questions for further clarification.
[7:02 pm, 20/12/2024] Arunan Sir: Too, text bookish, it reads. Let’s make it in the Chatshaala mode, as if talking over a cuppa tea, across the table.
I am sure, a non biologist like @~Vickram Crishna can be with us, too as much as most cubists, including those in plant science and microbiology.
[7:05 pm, 20/12/2024] Arunan Sir: Surely, this is complex enough and across conventional disciplines.
So, let’s go slow to get young cubists to ask queries too.
What do you say? @Sakshi @Enas @Theertha @~Batul Pipewala @Aditya Joshi
[7:11 pm, 20/12/2024] Dinesh Datta : Let’s think it like this.
In electric or copper wire,they can transmit electricity but cant modify or process the information.
Think of neurons like this.
10 neurons are next to each other.When first neuron receives the message,it can process and modify the signal.Like it can add extra information,remove some or even change the message(like touching a hot object is the message received to first neuron,it became withdrawal of arm at the last neuron).
Now in humans,it’s not just neurons,when we touch a hot object,the entire body changes from homeostasis,causes inflammatory,pain response,healing response,electrolyte changes,changes in temperature,breathing rate,hydration status and many more
[7:15 pm, 20/12/2024] Arunan Sir: Let’s try describing the first and second para, first. @Dinesh Datta
[7:17 pm, 20/12/2024] Arunan Sir: Please join Chatshaala to inspire all, as well as to get more inspired.
https://webinar.hbcse.tifr.res.in/b/kir-qwu-8bc-2ur
[7:34 pm, 20/12/2024] Dinesh Datta : Copper wires can’t modify or process the signal.
While neurons can.
However,now we are not looking at just neuronal modification or processing.
We are looking at ‘whole body response’.
I,e PNI(psychoneuroimmunology) and there’s significant body of evidence suggesting endocrinology is also interconnected.
@Rakesh Biswas
[8:46 pm, 20/12/2024] +91 : It needs a leap of understanding. Conventional thinking is largely aimed at pushing all thoughts and decisions into the complex specialised organ called the brain.
However, many ordinary observations, such as touching a very hot object, show us that decisions and decision-making can take place in a distributed manner.
Sets of neurons may therefore act together as action processors. Possibly this needs training, as very young babies might not be able to show this kind of behaviour.
So now we are able to understand that training is a mechanism by which sets of neurons begin to work together to carry out functions that do not need the brain.
Moving away from hot stoves, we can now understand more pleasant, or less painful, actions, such as returning a p…
[9:27 pm, 20/12/2024] Enas: The variability of compound-leaf forms is generated by flexible tuning of partially common players. It is therefore informative to study leaf development in different species. Cardamine (Cardamine hirsuta), pea (Pisum sativum), medicago (Medicago truncatula) and tomato (Solanum lycopersicum) all possess compound leaves. Here, we focus on key factors involved in leaf development in the above mentioned model plants. Leaf development of these plant species is presented in Box 1 and Figure 1. Using tomato leaf development as a context, we will stress the similar and divergent elements in leaf development of each of the model species as they are known today.Compound leaf development in model plant species - ScienceDirect
[9:27 pm, 20/12/2024] Enas: The xylem consists of tracheary elements, xylem parenchyma cells, and xylem fiber cells. Tracheary elements are dead, hollow cells with patterned cell walls comprising xylem vessels and tracheids, which function as conductive hollow tubes for water and nutrient transport throughout the plant body.Xylem Cell - an overview | ScienceDirect Topics.
[9:27 pm, 20/12/2024] Enas: Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period.The diverse roles of cytokinins in regulating leaf development | Horticulture Research.
[9:28 pm, 20/12/2024] Enas: Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period. Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period.
[9:28 pm, 20/12/2024] Enas: The diverse roles of cytokinins in regulating leaf development | Horticulture Research.
[10:46 am, 21/12/2024] Dinesh Datta : Yes.
There is a difference between nerve cell and nerve.
Basically,cell is fundamental living block of life.
Nerve cell is majorly ‘neuron’.
Kidney cell is mainly nephron.
Blood cells are mainly rbc,wbc,platelets.
Collection of cells forms a tissue…
Nerve is a bunch of ‘axons’ in Peripheral nervous system.
Collection of tissues/different types of cells functioning together forms an organ.
Different organs functioning together forms ‘organ system’.
Different organ systems,functioning together makes an ‘organism’ like humans here…
So,can anyone tell the Different ‘organ systems’ in human body?
[10:46 am, 21/12/2024] Dinesh Datta : Let’s breakdown from different organ systems to cells…
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Does hydra possess nervous system? If yes, how simple or complex it is?
@Lakshmy CUBE & others.
How many of you want coffee, if arunan sir will going to make it? But before saying “YES” think twice🧐because coffee will not come straightforward from his side while it will come with some lessons of basics; so pick it carefully.
In our hand 3Types of nerves involves in Reflex action.
