Attracting Abundance
- 106 -
The Law
Belief - XVIII
Our Cellular Biology - XVII
Our Cellular Biology - XVII
I will dedicate this post to our nerve cells and various terminologies associated with its structure and functioning. I thought that before learning about nerve cells, it would be interesting to learn some fundamental facts about our brain because this will also help us in understanding the research findings on belief, happiness and brain plasticity which will come up later.
The brain is a supercomputer residing in the head that gives us the capability to think. It receives signals from all over the body and sends back signals to whole of the body. Id draws its energy needs from sugar which is synthesized from the food that we eat. I called it a supercomputer but it is much more than that. A supercomputer is hardwired. The hardwiring does not change on is own when the application changes. The brain is plastic and it can adapt to things going on in our environment and in our lives. Some of the important features of the brain are as follows:
- It can weigh upto 1.4 kgs, which is about 2% of the body weight, but consumes 20% of all energy needed to keep the body going
- It is made up of three parts - the cerebrum, the cerebellum, and the brain stem
- The largest part of the brain, the cerebrum, is what we use to think with. It is also responsible for emotions and senses like touch, smell, taste, smell and vision i.e. the five senses.
- The "little brain" - cerebellum - helps in keeping the balance of the body and coordinating body movements
- The brain stem connects the brain to the spinal cord. It is responsible for executing those functions which do not need your conscious involvement such as, digestion, heart beating, breathing etc.
- The brain is divided into two halves; each half controls the opposite side of the body.
- Majority of the nerves connect to the spinal cord. There are twelve nerves that come from the brain itself; these control some important functions like vision, smell, facial movements, heart rate etc.
- The brain contains billions of nerve cells - neurons - that receive and transmit signals or impulses to various parts of the body.
- When you are born, you have all the neurons that you will ever have. However all the neurons are not connected in the beginning. the connections go on building and changing as new skills are learnt, new experiences are internalized. It was initially thought that the neuronal connections become permanent with age. However the recent research reveals that the new neural connections may happen in advanced years as well.
- Every memory is stored in an area of the brain called hippocampus.
- The brain works on electricity - the same power that makes the lights glow in your home.
- Out of all the oxygen that you breathe in, the brain uses 25% of it.
- The brain floats in a fluid called cerebrospinal fluid, that helps protect it and provides nutrients.
The nervous system is a complex collection of nerves and specialized cells, known as neurons, that transmit signals between different parts of the body. It is essentially the body's electrical wiring. The nervous system comprises of two parts - the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system is made up of the brain, spinal cord and nerves. The peripheral nervous system consists of sensory neurons, ganglia and nerves that connect to one another and to the central nervous system, and the ganglia (cluster of nerve cells).
Functionally, the nervous system has two main sub-divisions - somatic and autonomic. The somatic or voluntary system consists of nerves that connect the brain and the spinal cord with muscles and sensory receptors in the skin. The autonomic or involuntary nervous system regulates certain body processes, such as blood pressure and rate of breathing, that work without conscious focus.
Neurons, therefore, are the basic building blocks of the nervous system. Neurons are specialized to transmit information, in electrical and chemical forms, throughout the body. there are different types of neurons responsible for specific tasks in the body. Sensory neurons carry information from the sensory receptor cells throughout the body to the brain. Motor neurons transmit information from the brain to the muscles. Inter-neurons communicate information between the neurons.
Neurons contain organelles common to many other cells, such as nucleus and mitochondria. However they have some specialized structures like dendrites and axons besides the soma, axon hillocks, terminal buttons, and synapses
Dendrites are tree like extensions at the beginning of a neuron that help increase the surface area of the cell body. These dendrites receive chemical signal from other neurons, convert these signals to electrical impulses that are transmitted inside the cell body. The number and size of the dendrites varies from neuron to neuron depending on the function of the neuron. For example, the neurons of central nervous system have very long and complicated dendrites, which may receive signals from thousands of other neurons. If the electrical signals transmitted inside the cell is strong enough, an action potential is generated which results in the signal being transmitted down the axon.
Note: Action Potential is part of the process that occurs during firing of a neuron.
When a neuron is resting i.e. not sending signals, its inside is negatively charged relative to the positive charge outside the cell. The resting potential of the neuron refers to the difference between the voltage inside and outside the cell. The resting potential of average neuron is about (-)70 millivolts, indicating that the inside of the cell is 70 millivolts less than outside of the cell.
When the neuron receives the signal, the sodium channels in the cell membrane open and the positively charged sodium ions flood into the cell, till a threshold is reached. Once the threshold is reached, an action potential will fire, sending the electrical signal down the axon. Action potentials either happen or they don't; there is nothing like a partial firing of action potential.
After the neuron has fired, there is a nascent period in which another action potential is not possible. During this time the potassium channels open and potassium ions move inside the neurons and simultaneously a larger number of sodium ions exit the interior of the neuron thus restoring the negative charge inside the cell relative to the outside charge thus gradually returning the neuron to its resting potential. Now the neuron is ready for another firing.
The cell body, or soma, and the nucleus are not involved in transmission of signals. These two structures, like in other cells, maintain the cell and keep it functioning. They contain organelles like any other cell.
The axon hillock is the last part of the cell body, or soma, of a neuron that connects to the axon. This is where the membrane potentials generated by the synaptic inputs are summated before being transmitted to the axon.
An axon is a long thread-like part of a neuron through which impulses are transmitted from one neuron to other cells like other neurons, muscle cells and organs. The length of the axon can widely vary, say from a tiny one to as long as a meter long, depending on the location of the neuron. Larger the axon, faster is the rate of transmission of the signal. Some axons are coated with a fatty substance called myelin. The neurons with myelinated axons can transfer information much faster than other neurons. Most neurons have only one axon.
Note: Myein: a mixture of proteins and phospholipids forming a whitish insulation sheath around nerve fibres, which increase the speed at which signals are conducted.
Axons connect with other cells at junctions known as synapses.
The axons terminate at the terminal buttons. The terminal buttons contain vesicles holding neurotransmitters. At the end of the terminal button is a gap known as synapse. Neurotransmitters are used to carry the signal across the synapse to other neurons. When an electrical signal reaches the terminal button, neurotransmitters are released in to the synaptic gap. The terminal buttons essentially convert the electrical impulses into chemical signals. The neurotransmitters then cross the synaptic gap where they are then received by other neurons.
Note: Synapse is a junction between two neurons, consisting of a minute gap across which impulses pass by diffusion of neurotransmitter.
A neurotransmitter is a chemical messenger that carries signal from a neuron to other neurons and other cells in the body. More than 100 types of neurotransmitters have been identified so far. Neurotransmitters play a vital role in functioning of the body. A problem in these lead to diseases.
Neurotransmitters are also classified as per their function.
Namaste
See you soon
Prabir
Made by - AS Roma (own brand)
Neurons, therefore, are the basic building blocks of the nervous system. Neurons are specialized to transmit information, in electrical and chemical forms, throughout the body. there are different types of neurons responsible for specific tasks in the body. Sensory neurons carry information from the sensory receptor cells throughout the body to the brain. Motor neurons transmit information from the brain to the muscles. Inter-neurons communicate information between the neurons.
Neurons contain organelles common to many other cells, such as nucleus and mitochondria. However they have some specialized structures like dendrites and axons besides the soma, axon hillocks, terminal buttons, and synapses
Note: Action Potential is part of the process that occurs during firing of a neuron.
When a neuron is resting i.e. not sending signals, its inside is negatively charged relative to the positive charge outside the cell. The resting potential of the neuron refers to the difference between the voltage inside and outside the cell. The resting potential of average neuron is about (-)70 millivolts, indicating that the inside of the cell is 70 millivolts less than outside of the cell.
When the neuron receives the signal, the sodium channels in the cell membrane open and the positively charged sodium ions flood into the cell, till a threshold is reached. Once the threshold is reached, an action potential will fire, sending the electrical signal down the axon. Action potentials either happen or they don't; there is nothing like a partial firing of action potential.
After the neuron has fired, there is a nascent period in which another action potential is not possible. During this time the potassium channels open and potassium ions move inside the neurons and simultaneously a larger number of sodium ions exit the interior of the neuron thus restoring the negative charge inside the cell relative to the outside charge thus gradually returning the neuron to its resting potential. Now the neuron is ready for another firing.
The axon hillock is the last part of the cell body, or soma, of a neuron that connects to the axon. This is where the membrane potentials generated by the synaptic inputs are summated before being transmitted to the axon.
An axon is a long thread-like part of a neuron through which impulses are transmitted from one neuron to other cells like other neurons, muscle cells and organs. The length of the axon can widely vary, say from a tiny one to as long as a meter long, depending on the location of the neuron. Larger the axon, faster is the rate of transmission of the signal. Some axons are coated with a fatty substance called myelin. The neurons with myelinated axons can transfer information much faster than other neurons. Most neurons have only one axon.
Note: Myein: a mixture of proteins and phospholipids forming a whitish insulation sheath around nerve fibres, which increase the speed at which signals are conducted.
Axons connect with other cells at junctions known as synapses.
Note: Synapse is a junction between two neurons, consisting of a minute gap across which impulses pass by diffusion of neurotransmitter.
A neurotransmitter is a chemical messenger that carries signal from a neuron to other neurons and other cells in the body. More than 100 types of neurotransmitters have been identified so far. Neurotransmitters play a vital role in functioning of the body. A problem in these lead to diseases.
Neurotransmitters are also classified as per their function.
- Excitatory neurotransmitters: have excitating effect on the neurons making them more likely to fire. Ex: epinephrine
- Inhibitory neurotransmitters: have inhibiting effect on the neurons making them less likely to fire. Ex: serotonin
- Some neurotransmitters, like dopamine, can have both effect depending upon the type of receptor
Namaste
See you soon
Prabir
2013-14 Roma Trolley Travel Bag
Condition of bag - Brand new, unworn example in original AS Roma packaging with tags attached
Size - One size (60cm x 35cm x 55cm)
Made by - AS Roma (own brand)
Players - Totti, De Rossi, Pjanic, Strootman, Gervinho, Destro, Ljajic
Notes - Hard-cased travel bag with wheels and extendable handle from the season when Rudi Garcia took charge and led the Giallorossi to a storming start in Serie A, winning all 10 of their first games to set a new league record for consecutive victories. The side could not keep up this form for the whole season but finished as runners-up to secure a spot back in the Champions League. As the contract with Kappa was terminated the club decided to produce all the kit themselves, making all products from the campaign extremely hard to get hold of
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