Neurons are the basic unit of the nervous system and are composed of three main parts: dendrites, a cell body, and an axon. Dendrites receive signals from neighboring neurons and pass them to the cell body, which contains the nucleus and organelles. The signal then travels down the axon via electrical impulses to synaptic connections with other neurons. Myelin sheaths surround many axons and act as insulation to increase signal transmission speed. Together, neurons form complex networks responsible for our actions, thoughts, and consciousness.
Nerve impluse in non myelinated and myelinated nerve fibres. Nerve impluse is the sum total of chemical and physical events in the propagation of a wave of physiological activity along a nerve fibre.
Propagation of nerve impluse in non myelinated nerve fibres-
Resting state
Depolarisation
Repolarization
Metabolic pump
The action potential
The process of Propagation of nerve impluse in myelinated nerve fibres is called soltatory propagation.
Nerve impluses are transmitted in one direction only. The nerve fibre always have a refractory period after a stimulus and the nerve impluses obey the all or none law
The central nervous system (CNS) is made up of the brain and spinal cord. The brain controls most body functions, including awareness, movements, sensations, thoughts, speech and memory. The spinal cord is connected to the brain at the brain stem and is covered by the vertebrae of the spine.
Nerve impluse in non myelinated and myelinated nerve fibres. Nerve impluse is the sum total of chemical and physical events in the propagation of a wave of physiological activity along a nerve fibre.
Propagation of nerve impluse in non myelinated nerve fibres-
Resting state
Depolarisation
Repolarization
Metabolic pump
The action potential
The process of Propagation of nerve impluse in myelinated nerve fibres is called soltatory propagation.
Nerve impluses are transmitted in one direction only. The nerve fibre always have a refractory period after a stimulus and the nerve impluses obey the all or none law
The central nervous system (CNS) is made up of the brain and spinal cord. The brain controls most body functions, including awareness, movements, sensations, thoughts, speech and memory. The spinal cord is connected to the brain at the brain stem and is covered by the vertebrae of the spine.
Nervous system ( anatomy and physiology)Ravish Yadav
the topic contain function of nervous system, classification of nervous system, neurons anatomy, structural classification of neurons, functional classification of neurons, nerve impulse
LECTURE 99From Neurons to the Nervous System to the Brain The .docxmanningchassidy
LECTURE 99From Neurons to the Nervous System to the Brain
The neuron's place as the primary functional unit of the nervous system was first recognized in the late 19th century by the Spanish anatomist Santiago Ramón y Cajal (1852-1934), a neuroscientist and pathologist specializing in neuroanatomy and, especially, the central nervous system.
In 1888 Ramón y Cajal published a paper about the pigeon cerebellum. In this paper, he stated that he could not find evidence for cross connections (anastomosis) between axons and dendrites and called each nervous element "an absolutely autonomous canton." This became known as the neuron doctrine, one of the central tenets of modern neurobiology.
Above is his 1899 drawing of neurons in the pigeon cerebellum.
This Lecture focuses on the chemistry of neurons, specialized cells that transmit chemical and electrical signals to facilitate communication between the brain and the body. In learning about a new field, one can get befuddled very quickly with the jargon used by experts in the field and get lost, not being able “to see the forest for the trees.” So, before each section, I give a summary of Key Points and Key Terms you will need to understand that section. At the expense of “over kill,” I have repeated earlier “points” and “terms” at subsequent points in the Lecture so that you won’t have to “backtrack” to figure out what is going on.
Neurons are specialized cells that transmit chemical and electrical signals in the brain. They are the basic building blocks of the central nervous system.
Key Points:
· Neurons are specialized cells that transmit chemical and electrical signals in the brain; they are the basic building blocks of the central nervous system.
· The primary components of the neuron are the soma (cell body), the axon (a long slender projection that conducts electrical impulses away from the cell body), dendrites (tree-like structures that receive messages from other neurons), and synapses (specialized junctions between neurons).
· Some axons are covered with myelin, a fatty material that acts as an insulator and conductor to speed up the process of communication.
· Sensory neurons are neurons responsible for converting external stimuli from the environment into corresponding internal stimuli.
· Motor neurons are neurons located in the central nervous system (CNS); they project their axons outside of the CNS to directly or indirectly control muscles.
· Interneurons act as the “middle men” between sensory and motor neurons, which convert external stimuli to internal stimuli and control muscle movement, respectively.
Key Terms:
· glial cell: Non-neuronal cells that provide structure and support to neurons.
· synapse: The junction between the terminal of a neuron and either another neuron or a muscle or gland cell, over which nerve impulses pass.
· myelin: A white, fatty material composed of lipids and lipoproteins that surrounds the axons of nerves and facilitates swift commu.
Coordinates voluntary and involuntary actions of the body and transmits signals between different parts of the body.
Together with endocrine system controls and integrates activities of the body.
Nervous system allows us to perceive, understand, and respond to our environment.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
3. Neurons are the basic unit of the nervous system.
All cells of the nervous system are comprised of
neurons. The nervous system helps us to sense and
respond to our environment.
Neurons pass messages to each other using a special
type of electrical signal. Some of these signals bring
information to the brain from outside of the body,
such as the things we can see, hear, and smell.
Other signals are instructions for our organs, glands
and muscles.
So, the neurons (or nerve cells) are specialized cells
that transmit and receive electrical signals in the
body.
4. Neurons are composed of three main parts:
dendrites, a cell body, and an axon.
Neurons receive their signals from the
neighbouring neurons through their dendrites.
From there, the signal travels to the main cell body,
known as the soma. Next, the signal leaves the
soma and travels down the axon to the synapse.
Dendrites Cell body (soma) Axon
Synapse
5. It means tree like or branches like.
It receives the signals and forwards it to the cell
body.
6. The cell body is called as perikaryon since its nucleus is
always found at periphery. It has following components:
Nucleus - It contains genetic material (chromosomes)
including information for cell development and synthesises
proteins, necessary for cell maintenance and survival. It is
covered by a membrane.
Nucleolus - It produces ribosomes necessary for
translation of genetic information into proteins.
Nissl Bodies - It is the groups of ribosomes used for
protein synthesis.
7. Endoplasmic reticulum (ER) - The system of
tubes for transport of materials within cytoplasm. It
has ribosomes (rough ER) or no ribosomes (smooth
ER). With ribosomes, the ER is important for
protein synthesis.
Golgi Apparatus - The membrane-bound structure
important in packaging proteins.
Microfilaments/Neurotubules - The system to
transport materials within a neuron and may be used
for structural support as well.
Mitochondria - It produces energy to fuel cellular
activities.
8. Axons are the structure found on a single axis. It is
cylindrical in shape.
They are also called as nerve fibres.
It varies in length (can be over 1 meter long).
The longest axon is called the dorsal root
ganglion (DRG), from the skin to the brain.
Most axons are covered by a white, waxy substance
called myelin sheath.
This coating insulates nerves and increases the speed at
which impulses travel.
Myelin is created by Schwann cells in the peripheral
nervous system and oligodendrocytes in the CNS.
9. There are some structures related to axon:
1. Axon hillock: The cell body and axon where
joins, they form a triangle like structure. It is called
as axon hillock.
2. Axon collateral: When an axon joins with the
axon of another axons, then this is called as axon
collateral.
3. Initial segment: It is the point where axon gets
started.
4. Trigger zone: The space between axon hillock
and initial segment is termed as trigger zone.
There are small gaps in the myelin coating, called
nodes of Ranvier. The action potential jumps
from gap to gap, allowing the signal to move much
quicker.
10.
11. 1. Dendrites: It receive electrical impulses from
neighboring neurons.
2. Soma: The cell body which contains most of the
cell’s organelles.
3. Nucleus: It contains the cell’s DNA.
4. Axon: It transfers electrical impulse signals from the
cell body to the synapse.
5. Myelin sheaths: It Cover the axon and work like
insulation to help keep electrical signals inside the cell,
which allows them to move more quickly.
6. Synapses: It Sends electrical impulses to neighboring
neurons.
12. So, it is the complexity of neuronal networks that
gives us our personalities and our consciousness.
They are responsible for the most basic of actions,
and the most intricate. From automatic reflex
actions to deep thoughts.