Nerve impulse conduction involves the generation and propagation of action potentials along neurons. At rest, neurons maintain a negative resting potential due to an unequal distribution of ions across the cell membrane. When stimulated, the opening of voltage-gated sodium channels causes rapid depolarization and the generation of an action potential. This potential then propagates along the axon as adjacent regions are depolarized, triggering their own action potentials. At synapses, the action potential is converted to a chemical signal via neurotransmitter release, which can then trigger a new action potential in the post-synaptic cell. Myelination and large axon diameters increase conduction velocity.
these slides contain a brief introduction of neurons and its classification as well as details of generation of action potential, resting potential and eletrotonic potential.
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
these slides contain a brief introduction of neurons and its classification as well as details of generation of action potential, resting potential and eletrotonic potential.
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland.
A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland.
description about neurones,
General introduction
Neurone classification – Myelinated and Non – Myelinated
Special features of a neurone
Resting Membrane Potential
Action Potential
Nerst Equation
Ionic distribution
Synaptic transmission
Conclusion.
Myelinated Neurone,nonMyelinated Neurone.
special properties of neurone(excitability,conduction,transmission,integration,excitability).
Rwsting membrane potential,action potential.nernst equation,ionic distribution of extracellular ions and intracellular ions.a little bit about how synaptic transmission occurs.from one nerve to another nerve.nerve impulse generation.neuro humoral transmission,etc.
This presentation contains the basic information about nerve cells and action potential. This work is done for academic purpose only so if you are using give proper reference.
Nerve Impulse is defined as a wave of electrical chemical changes across the neuron that helps in the generation of the action potential in response to the stimulus. This transmission of a nerve impulse across the neuron membrane as a result of a change in membrane potential is known as Nerve impulse conduction.
Mechanism of Nerve Impulse Conduction
Nerve impulse conduction is a major process occurring in the body responsible for organized functions of the body. So, for conduction of nerve impulse there are two mechanisms:
Continuous conduction
Saltatory conduction
A synapse is a small gap at the end of a neuron that allows a signal to pass from one neuron to the next. Neurons are cells that transmit information between your brain and other parts of the central nervous system. Synapses are found where neurons connect with other neurons.
Synapses are key to the brain's function, especially when it comes to memory.Synapses connect neurons and help transmit information from one neuron to the next. When a nerve signal reaches the end of the neuron, it cannot simply continue to the next cell. Instead, it must trigger the release of neurotransmitters which can then carry the impulse across the synapse to the next neuron.
Once a nerve impulse has triggered the release of neurotransmitters, these chemical messengers cross the tiny synaptic gap and are taken up by receptors on the surface of the next cell.
These receptors act much like a lock, while the neurotransmitters function much like keys. Neurotransmitters may excite or inhibit the neuron they bind to Synapses are composed of three main parts:
The presynaptic ending that contains neurotransmitters
The synaptic cleft between the two nerve cells
The postsynaptic ending that contains receptor sites
An electrical impulse travels down the axon of a neuron and then triggers the release of tiny vesicles containing neurotransmitters. These vesicles will then bind to the membrane of the presynaptic cell, releasing the neurotransmitters into the synapse.
My first attempt at this presentation for the IB Diploma Programme Biology course: topic 6.5 neurons and synapses. I'm hoping another great educator out there can take this, make it look a lot better, and then share it :)
Thanks to Steven Taylor and Chris Paine for all of their work and inspiration.
Please download and modify as you wish.
final note: I actually made this in google slides - I just checked the presentation and none of the links to the videos I used are there. Here is a link to the google slide presentation so you can find the videos: https://docs.google.com/a/igbis.edu.my/presentation/d/1eabpxEtwlDGt7EPRqQ_GPwxUBerszZQquWAhjRnU_WE/edit?usp=sharing
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The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
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How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2. CONTENTS
1.Structure of a nerve cell
2. Resting Potential
3. Action Potential
(a) Formation of an action
potential
4. Propagation of Action
Potentials as an Impulse
(b) Saltatory conduction
5. Neurotransmission: Jumping
the Synaptic Cleft
4. Neuron
• Dendrite - conducts “signal” toward the cell body -- [input zone]
– often short, numerous & highly branched
– signal comes from sensory cell or neighboring neuron
• Axon - usually a single fiber -- [conducting zone]
– conducts signal away from cell body to another neuron or effector cell
• Axon Ending
– a cluster of branches (100’s to 1000’s)
– each with a bulblike synaptic knob
– relays signal to next neuron / effector cell
6. RESTING POTENTIAL
Resting potential may be defined as the
difference in voltage between the inside and
outside of the cell as measured across the
cell membrane.
• When a neuron is not being stimulated, it
maintains a resting potential
Ranges from –40 to –90 millivolts (mV)
Average about –70 mV
7. RESTING POTENTIAL
• Two major forces act on ions in establishing
the resting membrane potential
1. Electrical potential produced by unequal
distribution of charges
2. Concentration gradient produced by
unequal concentrations of molecules
from one side of the membrane to the
other
8. RESTING POTENTIAL
• Sodium–potassium pump creates significant
concentration gradient
• Concentration of K+
is much higher inside the
cell
• Membrane not permeable to negative ions
• Leads to buildup of positive charges outside
and negative charges inside cell
• Attractive force to bring K+
back inside cell
• Equilibrium potential – balance between
diffusional force and electrical force
8
9. ACTION POTENTIAL
• Action potential may be defined as the entire series of
changes which contribute towards the changes in
membrane potential.
Action
potentials:-
– Result when depolarization reaches the threshold
potential (–55 mV)
– Depolarizations bring a neuron closer to the
threshold
– Hyperpolarizations move the neuron further from
the threshold
– Caused by voltage-gated ion channels
• Voltage-gated Na+
channels
• Voltage-gated K+
channels
10. ACTION POTENTIAL
• Voltage-gated Na+
channels
– Activation gate and inactivation gate
– At rest, activation gate closed, inactivation gate
open
– Transient influx of Na+
causes the membrane to
depolarize
• Voltage-gated K+
channels
– Single activation gate that is closed in the resting
state
– K+
channel opens slowly
– Efflux of K+
repolarizes the membrane
11. ACTION POTENTIAL
• The action potential has three phases
– Rising, falling, and undershoot
• Action potentials are always separate, all-or-
none events with the same amplitude
• Do not add up or interfere with each other
• Intensity of a stimulus is coded by the
frequency, not amplitude, of action potentials
11
14. PROPAGATION OF ACTION
POTENTIAL
• Propagation of action potentials
– Each action potential, in its rising phase,
reflects a reversal in membrane polarity
– Positive charges due to influx of Na+
can
depolarize the adjacent region to threshold
– And so the next region produces its own
action potential
– Meanwhile, the previous region repolarizes
back to the resting membrane potential
• Signal does not go back toward cell
body
16. PROPAGATION OF ACTION
POTENTIAL
• Two ways to increase velocity of conduction
–Axon has a large diameter
• Less resistance to current flow
• Found primarily in invertebrates
–Axon is myelinated
• Action potential is only produced at the
nodes of Ranvier
• Impulse jumps from node to node
• Saltatory conduction
16
18. NEUROTRANSMISSION
• Electrical [no synapse]
– common in heart & digestive tract - maintains steady,
rhythmic contraction
– All cells in effector contain receptor proteins for
neurotransmitters
• Chemical - skeletal muscles & CNS
– presence of gap (SYNAPTIC CLEFT) which prevents action
potential from moving directly to receiving neuron
– ACTION POTENTIAL (electrical) converted to CHEMICAL
SIGNAL at synapse (molecules of neurotransmitter) then
generate ACTION POTENTIAL (electrical) in receiving
neuron
19. Overview of Transmission of Nerve Impulse
• Action potential
→ synaptic knob
→ opening of Ca+
channels
→neurotransmitter vesicles fuse with
membrane
→release of neurotransmitter into synaptic cleft
→binding of neurotransmitter to protein receptor
molecules on receiving neuron membrane
→opening of ion channels
→triggering of new action potential.
23. NEUROTRANSMISSION
• Action potential
→binding of
neurotransmitter to
protein receptor
molecules on receiving
neuron membrane
→opening of sodium
channels
→triggering of new
action potential
24. NEUROTRANSMITTERS
• Amino acid derived Neurotransmitters
– Derived from amino acid tyrosine
norepinephrine, epinephrine
• Amine Neurotransmitters
– acetylcholine, histamine, serotonin
• Amino Acids
– aspartic acid, GABA, glutamic acid, glycine
• Polypeptides
– Include many which also function as hormones
– endorphins
25. References
• Cell and Molecular Biology by Gerald Karp
• Cell and Molecular Biology,8th
ed.E.D.P.
Robertis and E.M.F. De Robertis
• Net source:- www.freeman.karp.in
• For any query contact-9896543665
