Hello everybody…. This post is a little different…and will surely poke the Neurons!😋 We all know that spinal dysraphism syndromes present with the external manifestation of a tuft of Hair….ever wondered why?🤔 Well there is active research going on in this field and very little is known about it..but from the articles already published and […]
Hello everybody….
This post is a little different…and will surely poke the Neurons!😋
We all know that spinal dysraphism syndromes present with the external manifestation of a tuft of Hair….ever wondered why?🤔
Well there is active research going on in this field and very little is known about it..but from the articles already published and by reading different books I tried to consolidate it….and hope it’s easy to understand too….
So let’s start with development of hair…and understand why all of it gets concentrated at one place…? Hair development is the result of neuroectodermal-mesodermal interactions …..and signalling.(meaning we have the cells forming the nervous tissue plus the soft tissue cells which will take part in the development of Hair). The spacing, orientation and density various other patterns of Hair are driven by activators which incite the development of hair… are established…. by the skin epithelium and mesenchyme. Now an important concept ..hair development is under the dominant-negative influence of inhibitors of the hair follicles….. meaning the hair follicle has to overcome a lot of local negative influence in order to develop….if it were not so we would have had hair everywhere…like we have it on our scalp….😨 Which would be weird🐏Hence the differentiation pathway must be locally negated by specific antagonists and/or overriden by stimulators of hair formation. If this process is successful we have development if hair follicles in that area…So in this senario …we need the wnt pathway to function....for spacing and proper differentiation of Hair….. (WNT gene)
The neural tube defects have been known for disturbed wnt pathway… Locally which leads to improper closure of mesenchyme forming the vertebra and improper signalling leading to improper differentiation of hair follicles on the above skin and forming A TUFT OF HAIR.☺
I hope this post was helpful.
Do let me know if I missed anything above or if you have more information on the topic. Happy to learn😀
-Medha😉
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Source: Brains!
Hello… everyone… Today… We will delve into the contents of the Blob(The human Brain)… learning more about the contents that form the brain…the basic structural unit of…
Source: What’s in the Blob?
Hello… everyone…
Today… We will delve into the contents of the Blob(The human Brain)… learning more about the contents that form the brain…the basic structural unit of the brain Called the Neuron!(sounds like Moron…😅 But well it’s the smartest cell in our Body….😎and if it decides to misbehave we would certainly be called as Morons then!😛)
Just a recap here… regarding the nervous system ….it has an axial organization . The brain and spinal cord, which constitute the central nervous system (CNS), run along the midline. The CNS receives information and sends messages through the various Neurons!. The basic structural and signal processing unit of the nervous system is the neuron.
Let’s see how the neuron works…on the inside….
A neuron is basically a cell, and hence has the basic features of a cell: the nucleus and cytoplasm, which form the cell body. But to meet its special functional needs, the cell body has extensions of the cytoplasm. The extensions which specialize in receiving messages are called dendrites, and the extensions which transmit messages from the cell body are the Axons.
So the neuron has a headquarter for itself …The Nucleus of the cell…. Imagine that a wise old man is sitting in a chamber looking at the computer screen where all the information/messages from the outside world are been displayed….he has many subordinates working for him analysing the information being received as he himself would be unable to to decode …..all of it.(approximately 30,000 signals that they receive every second… Isn’t it insane😨 amount of work!)….
Now the chief at the headquarter has to be efficient and take quick decisions regarding the response that has to be generated by the neuron….Once the decision is made ….the message is conveyed to the neighborhood Neurons via the speedy runners (some what like the Cartoon Road Runner💨) these carry the neurotransmitters .. and set a unidirectional chain of command… in motion …that ends as the (receptor organ or muscle)response to the stimulus received.
The Brain is made up of so many of these self sustaining Neurons… that take decisions and respond to a variety of different stimuli….quicky and efficiently once it has the status update on all the other systems of the body.
The speedy runners run on their respective tracts and deliver the messages. These tracts are present within the cytoplasmic extensions that take the signals away from the cell body …aka the Axons! (The longest axons extend from the Brain till your pinky toe! They can be that long….😵😱)
These tracts terminate at the end of Axons..the ends of Axons are a little swollen to increase the area of contact with the surface where it terminates… for more and better transmission of the messages with the help of the Neurotransmitters!..
The Neurotransmitters are either excitatory or inhibitory to the successive neuron …. Depending on the response desired. Each Neurotransmitters is like a unique key which fits into its respective slot on being released from the bulbous Axonal end.
This junctional space between the two Neurons is called a the Synapse!…
We’ll learn more about the Synapses and the various responses that are generated in subsequent posts…..😁
I hope this has been helpful and not boring …..and hope you guys liked it.
_Medha🐝
Hello…. everyone…. So let’s get started and drive our way thorough the central nervous system… So the basics… We have a Brain …(yes we all do😂) the brain is be… Source: How was the Bolb made?…
Source: How was the Blob made?
Hello…. everyone….
So let’s get started and drive our way thorough the central nervous system…
So the basics… We have a Brain …(yes we all do😂) the brain is been allotted a certain set of function to perform in order to maintain equilibrium within the body and with the surroundings.
So the brain has evolved over all these years and attained it’s final form….(really complex stuff). So in its final form we have a Central Nervous system which contains… The brain… Called the cereBrum ,the midbrain,Pons ,Medulla ,and the spinal cord with its spinal nerves…. also to aid it’s function we have a peripheral nervous system…. which handles the local matters in the body …whereever the CNS can’t physically reach…Don’t worry about the terminology they will all soon make sense….
Let’s just get a brief review of the evolution …for us to make more sense of the structure and function of the central nervous system.
The first development was…of appearance of a few cells in multicellular organisms which were very sensitive to changes in the environment..in order to communicate and coordinate within the organism….these sensitive cells developed the ability to communicate with one another. Communication across the distance between them was achieved through the development of various cell wall extensions called as processes. (The now called axons and Dendrites)Now…with the development of processes the messages could be transferred between them… But which way should the message flow….away or towards the cell??.🤔….to solve this confusion…there was development of one-way traffic in the processes so that a process was either bringing a message to the cell(Dendrites) or carrying a message away from the cell(Axons).Another….development was the tendency of these sensitive cells, to form Groups…..(groupism doesn’t spare anyone..well this was a well formed and essential one.😛) these groups had a complex circuitry which could function and process the information so efficiently that would not be possible with a simple chain of neurons…..( See The power of mobs…. since time immemorial😎)These groups of cells were later called ganglia.
A major development which may be termed the beginning of a revolution was the appearance of bilateral symmetry in the animal kingdom.This fancy term denotes nothing but having similar functioning body parts…on either side. In bilaterally symmetrical animals… it was possible to achieve specialization at one end which would enable the animal to move about…using both his limbs so that the coordination wouldn’t be sacrificed….in simple organism who were not bilaterally symmetrical this didn’t happen as they moved in any direction they were stimulated…. like the algae…Due to this phenomenal evolution of the simple cell clusters…the group of cells predominately occupied the head end of the organisms….and the head developed a specially big cluster of of these cells i.e. the Neurons….!and this lead to the development of a primitive Brain…. Now the…receptor organs, specially sensitive to light, sound or chemical changes also developed at the head end, and these got information from the environment and sent it to the Brain. This information at the head end helped the animal in locomotion and find food and mate for itself…..
I hope this brief overview … stimulated and sensitized your head end…. And you got an idea about the evolution and formation of the Mystical Brain….
I’ll be back …with the some new cool and easy to understand blogs on development of human nervous system with a video explaining the same….
Thank you ..very much …for Reading…do like and comment on the mistakes any special additions or recent developments that you have noticed…. On this subject….
Let’s make learning simple and Fun…😊
Hello everybody….. From today ….everyday I will be posting on the topic of Central nervous system. I know it is the most confusing and daunting system as a medical student but u will tr…
Source: The Blob of Squishy Mush.
Hello everybody…..
From today ….everyday I will be posting on the topic of Central nervous system.
I know it is the most confusing and daunting system as a medical student but u will try and keep it as simple as it can get…. Without boring you guys.
Starting with embryology I will cover till the topic of neurosurgery!
I hope you guys will like and enjoy the posts…as much I will enjoy making them..
See you guys soon.😀
Hello!
After driving through the Neurons we have reached at the end of one neuron and the beginning of another…. the Synapse!…. (synapsis meaning a junction) It was coined by the eminent neurophysiologist, Sir Charles Sherrington. The talking between two neurons across a synapse is called synaptic transmission.
Neurons in the CNS are highly interconnected. Just like bunch of GirlBffs … One gossip travels faster than the speed of light ,sound everything….Girls will be Girls!!!! 👱 In the human brain we have about 1011 neurons, and each neuron receives about 1000 synaptic connections.😱😵A huge group of Bffs! And they make about 1014 synaptic connections.It literally means that every part of the brain is directly or indirectly connected to every other part…. No secrets here!😷
Neurons send information across junctions called synapses. To have a smooth streamlined command the transmission across synapses is one-way, and is mediated by a chemical called the neurotransmitter(the gossip). The presynaptic neuron releases the neurotransmitter.So from our analogy …..the Bffs …some of the Girls got a new gossip…they will now give the message to the other Girls of the squad.. (here the neurons ) and they will relay it to the next….and this will continue… The neurotransmitter …(gossips) comes in two flavors Glutamate… meaning forward the gossip …and Glycine or GABA saying keep the gossip to your self…. The arrival of the Neurotransmitter (gossip)…then incites a reaction with its receptor on the postsynaptic neuron… (the receiver girl)….Formation of the neurotransmitter-receptor complex (the gossip and its receptor)changes the excitability of neuron….if the message is a Glutamate! 💨(Let the gossip circulate)The next girl will set in action and the message would be transmitted….but if the message says STOP!🚨(Keep the message to yourself!) The Girl stays still. …and looks pretty!👰
We now know that the Neurons are highly interconnected ….which means single neuron receives messages from a large number of presynaptic neurons at a time…. which is a lot of…Glutamates and Glycines…. now how is the neuron (Girl)supposed to decide what to do ???? So….in this situation The response of the postsynaptic neuron(girl) depends on the integrated summation of all the messages it receives… (Majority in the received messages winds..🎖) And depending whether the majority was for Glutamate or Glycine the Girl decides to either circulate the gossip or keep it to her self..
The neuronal connections can get very confusing at times…. but we shall go step by step and decode them😎 so no need to worry.
Let me know if the analogy was useful…or was too confusing 😅
We’ll learn more on synapses in subsequent posts…😃
-Medha👩
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