-ˋˏ ༻ News ༺ ˎˊ-
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Introducing The Laminae:
Origin:
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Redoing this section
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Datura Nightshade
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Her First Day:
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I like to gather from the world around me as I process it and draw my own conclusions
I’m a guardian at heart and I will be here when I sense potential danger
When you are hurting I will be here
When danger is approaching I sound the alarm, loudly
Your journey is long, I will be here
I will communicate with you in the form of thoughts, to keep our words discrete
I have the ability to defend you, I can fire energies quite a distance away
Light to show the way, energy to attack and defend
I can grab onto pieces of my surroundings and put them together if a path is not clear or an obstacle too big to climb
The knowledge I return with will be made useful and I will offer you support as needed
When I gather from my environment I’m quite sensitive in a way. I can detect small changes in what creates the world around me
I will bring the information to you right away
Just as a warning sometimes I go into a state where I can be wrathful on whoever is in my way
When this happens I usually go off alone for a while rather than doing damage
At times when my wrath is helpful I organize an attack at the weakest part of the enemy
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Part 1 Interphase Continued: G1 Phase (Gap 1):
During the G1 phase, the cell actively synthesizes proteins
the process of creating complex molecules from simpler ones through chemical reactions
Synthesis involves both the breakdown of molecules for energy:
catabolism:
the set of metabolic pathways:
Pentose Phosphate Pathway:
It serves as an alternative route to glycolysis for glucose oxidation, primarily producing NADPH and ribose 5-phosphate.
NADPH is crucial for reducing oxidative stress and supporting anabolic processes, while ribose 5-phosphate is a precursor for nucleotide synthesis
NADPH Production:
NADP/NADPH is essential for building larger molecules from smaller ones.
It provides reducing power (electrons) for reactions
Ribose 5-Phosphate Synthesis:
The PPP can be divided into oxidative and non-oxidative branches.
In the oxidative branch:
glucose-6-phosphate
a central hub in cellular metabolism, connecting several key pathways. G6P, formed by the phosphorylation
phosphorylation is described as the "transfer of a phosphate group" from a donor:
Phosphorylation acts as a molecular switch, modifying the activity, stability, or interactions of proteins. Kinases, enzymes that catalyze phosphorylation, add phosphate groups to specific amino acids on target proteins, often altering their shape and function
to an acceptor:
a molecule that receives a phosphate group (PO3-) during a phosphorylation reaction
glucose, serves as a starting point for glycolysis
glucose-6-phosphate is converted to ribose 5-phosphate and NADPH.
The non-oxidative branch:
interconverts 3-, 4-, 5-, 6-, and 7-carbon sugars, also producing ribose 5-phosphate.
The pathway produces ribose 5-phosphate, a sugar that is a precursor for nucleotide synthesis (DNA and RNA)
Redox Homeostasis:
Link to Glycolysis:
The PPP can be linked to glycolysis through intermediates like glyceraldehyde 3-phosphate and fructose 6-phosphate, allowing for the interconversion of sugars and metabolic flexibility
Phases of the Pathway:
Oxidative Phase:
This phase involves the irreversible oxidation of glucose 6-phosphate to ribulose 5-phosphate, producing NADPH and carbon dioxide
Non-Oxidative Phase:
This phase involves a series of reversible reactions that convert pentose phosphates (like ribulose 5-phosphate) into other sugars, including intermediates of glycolysis like fructose 6-phosphate and glyceraldehyde 3-phosphate
Fermentation:
transforming molecules from one form to another
Steps include:
Glycolysis:
Krebs Cycle:
Beta-oxidation:
Electron Transport Chain:
that break down large molecules into smaller ones, releasing energy in the process
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and the use of that energy to build new molecules:
anabolism:
Steps include:
Gluconeogenesis:
Glycogenesis:
Fatty Acid Synthesis:
Protein Synthesis:
the process of building complex molecules from simpler ones, requiring energy input
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This includes building blocks like amino acids:
the building blocks of proteins
and nucleotides:
repeating units:
repeating units are the fundamental building blocks that make up larger molecules and structures. These units are linked together in a chain-like manner to form polymers.
They consist of three key components:
a nitrogen-containing base:
In the double helix structure of DNA, adenine always pairs with thymine.
This pairing is mediated by hydrogen bonds, which are weak yet numerous, and are essential for holding the two strands together
This pairing ensures that when DNA replicates or is transcribed into RNA, the new strands are accurate copies of the original
In DNA, guanine always pairs with cytosine
a five-carbon sugar:
ribose:
a sugar of the pentose class which occurs widely in nature as a constituent of nucleosides and several vitamins and enzymes
or deoxyribose:
a sugar derived from ribose by replacing a hydroxyl group with hydrogen
a phosphate group:
Nitrogenous Base:
Purines:
These are double-ringed structures
purines always pair with pyrimidines to form complementary base pairs
Pyrimidines: These are single-ringed structures
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It also accumulates the necessary energy reserves for DNA replication.
Each chromosome consists of a single DNA molecule at this stage
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The G1 phase includes a checkpoint where the cell assesses its conditions and decides whether to proceed with division.
Factors like DNA integrity and cell signals can affect this decision
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Part 1 Interphase Continued: S Phase (Synthesis):
a part of interphase where DNA replication occurs, resulting in each chromosome
Chromosomes are composed of DNA tightly wound around proteins called histones
Histones are classified as basic proteins due to their high proportion of positively charged amino acids like:
lysine
arginine
This positive charge is essential for their interaction with the negatively charged DNA
DNA wraps around histone proteins to form nucleosomes
which are further compacted into chromatin and then chromosomes
Each chromosome has a constriction point called a centromere
which divides it into two arms
(p and q)
and is important for chromosome separation during cell division
each chromosome is duplicated, forming two identical sister chromatids
The centrosomes
which organize the microtubules:
of the meiotic spindle:
also replicate during the S phase
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Part 1 Interphase: G2 Phase (Gap 2):
The third stage
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Sage Obsidian
♂
I will provide a brief science explanation for this character who is classified as Laminae II
Laminae II consists of projection neurons (Golgi type I neurons)
Involved in sensory information transmission, Transmit signals from one area of the nervous system to another, such as peripheral nerves and long tracts of the brain and spinal cord.
peripheral nerves
nerves that branch out from the central nervous system (brain and spinal cord) and extend to the rest of the body
They act like wires, transmitting messages back and forth between the brain and various parts of the body
These nerves are responsible for a wide range of functions, from controlling movement and sensation to regulating involuntary functions like breathing and digestion
Have many dendritic branches
the treelike extensions of a neuron that receive signals from other neurons.
These branches are essential for neuronal communication and function, with their unique branching patterns being highly correlated with the neuron's specific role
including dendritic protrusions and short hair-like appendages
Long axons that extend over considerable distances, allowing for the transmission of signals to different parts of the nervous system
and local interneurons (Golgi type II neurons)
also known as microneurons
also known as microneurons, are characterized by short axons or sometimes lacking axons altogether.
Axons transmit electrical signals (action potentials) away from the neuron's cell body (soma).
Many axons are surrounded by a myelin sheath, a fatty insulating layer that speeds up the transmission of electrical signals.
At the end of an axon are axon terminals (synaptic terminals), which release neurotransmitters to communicate with other cells.
They are a type of interneuron within the central nervous system, meaning they connect neurons within a specific brain region rather than projecting to distant areas.
These neurons are crucial for local circuit function and can be either excitatory or inhibitory, contributing to the complex processing of neural information
They are a type of neuron found in the central nervous system, with smaller soma
and fewer dendritic branches compared to Golgi type I neurons.
Type II Golgi neurons
Golgi cells are often inhibitory interneurons
Inhibitory interneurons release GABA, which hyperpolarizes
Hyperpolarization means an increase in the difference in electrical potential across a cell membrane, making the inside of the cell more negative relative to the outside
or inhibits the postsynaptic neuron
A postsynaptic neuron is a nerve cell that receives signals from another neuron through a synapse.
It's the neuron that "receives" the message after it's been transmitted across the gap between neurons, where chemical signals called neurotransmitters play a role.
The postsynaptic neuron then processes this input and can potentially generate its own signal
inhibitory interneurons are less likely to fire an action potential
thus reducing the excitatory influence on the target neuron
They help regulate the activity of neuronal circuits by controlling the balance between excitatory
and inhibitory inputs
contributing to the stability and proper functioning of neural networks
GABA is a primary inhibitory neurotransmitter in the central nervous system, acting to calm and regulate brain activity. It's crucial for maintaining a balance between excitatory and inhibitory neurotransmission
Excitatory neurotransmission is the process by which chemical signals from a neuron (the sending cell)
a cell that transmits a signal to another cell, often through the release of chemical messengers. These messengers, known as signaling molecules or ligands, travel to a target cell and bind to receptors on its surface, triggering a response
excite the next neuron (the receiving cell)
a receiving cell (also called a target cell or recipient cell) is a cell that has the ability to receive and respond to signals from other cells or its environment.
These cells have specific receptors on their surfaces that can bind to signaling molecules, triggering a cascade of events that leads to a cellular response
increasing the likelihood that it will fire an action potential
These chemical messengers bind to receptors on the postsynaptic neuron
leading to depolarization
which means the cell's membrane potential becomes less negative, increasing the likelihood of an action potential
impacting various neurological functions and contributing to the regulation of mood, sleep, and anxiety
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Lotus Lamb
♀
I will provide a brief science explanation for this character who is classified as Laminae III
Lamina III a layer within the dorsal horn of the spinal cord, specifically the superficial part of the nucleus proprius
The nucleus proprius is a sensory nucleus in the spinal cord's posterior horn, playing a key role in processing sensory information like touch, vibration, and proprioception.
It's located beneath the substantia gelatinosa and spans the length of the posterior horn
Characterized by a gelatinous, pale, and crescent-shaped appearance due to the lack of myelinated fibers
substantia gelatinosa plays a crucial role in the gate control theory of pain
where it modulates sensory signals from primary afferent neurons
Contains various interneurons, including:
islet cells
Islet cells in the spinal cord are specialized neurons located in the substantia gelatinosa (SG), a region in the dorsal horn responsible for processing sensory information
These cells have a distinct morphology, including long, often sagittal-oriented dendrites
Islet cells are primarily inhibitory, releasing GABA, and some also co-localize with glycine, which further contributes to their inhibitory function
central cells
stalked cells
and radial cells
which can be GABAergic or glutamatergic
Contains neurons that receive input from both low-threshold and high-threshold primary afferents.
It's characterized by the presence of numerous myelinated fibers
and neurons
and it's known to receive input from both low-threshold and nociceptive high-threshold primary afferents
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Damiana Kunzite
♀
I will provide a brief science explanation for this character who is classified as Laminae IV
Lamina IV has a more heterogeneous mix of cell sizes, including both large and small cells adjacent to each other. Lamina IV also extends laterally, without the bend present in the first three laminae
Also involved in processing vibration and pressure touch sensations and carrying conscious proprioceptive information to the cerebral cortex
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Neroli Quicksilver
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I will provide a brief science explanation for this character who is classified as Laminae V
Lamina V neurons are involved in processing sensory afferents from nociceptors (pain receptors)
Lamina V is characterized by its diversity, with ten different neuron types and extensive dendritic interconnections
Within Lamina V, there are two distinct zones: the lateral zone with darkly staining cells and the medial zone with lighter cells
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Azalea Stone
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I will provide a brief science explanation for this character who is classified as Laminae VI
Lamina VI plays a role in the flexion reflex, a spinal reflex that allows withdrawal from painful stimuli
It receives information from muscle spindles, which are sensory receptors that detect muscle length and movement
It works in conjunction with other laminae, particularly lamina VIII, to coordinate spinal reflexes
It relays information from muscle spindles and other sensory receptors to the brain via spinocerebellar tracts
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Rue Musk
♂
I will provide a brief science explanation for this character who is classified as Laminae VII
Laminae VII, also known as the intermediomedial nucleus or intermediolateral nucleus
Acts as a relay station for sensory information from other laminae
Contains interneurons and propriospinal neurons that help mediate reflexes and transmit signals within the spinal cord
Plays a role in visceral motor function, particularly in the thoracic and upper lumbar regions
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Senna Verbena
♂
I will provide a brief science explanation for this character who is classified as Laminae VIII
Contains interneurons and projection neurons
It influences the activity of gamma motor neurons, which innervate intrafusal muscle fibers (muscle spindles)
Receives input from various tracts, including the vestibulospinal and reticulospinal tracts
Projects to motoneurons on both the same and opposite sides of the spinal cord
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Magnolia Saffron
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I will provide a brief science explanation for this character who is classified as Laminae IX
Lamina IX is not a true lamina. It is a set of columns in the lamina VII and VIII
The cells have an abundance of Nissl substance
Lamina IX houses collections of motor neurons, including alpha and gamma motor neurons
Contains Alpha Motor Neurons and Gamma Motor Neurons
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Magnolia‘s Design
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Dorsal Horn
The dorsal horn contains various types of neurons, including primary afferent fibers
projection neurons:
a type of neuron in the central nervous system (CNS) that transmit information to distant regions of the brain or spinal cord
They have long axons
the function of axons is to carry electrical impulses that are the means of communication within the brain and between the brain and the rest of the body
that extend from their cell bodies to distant targets
Their axons project to areas outside the structure they originate from, unlike interneurons which project locally within the same structure
Spinoparabrachial projection neurons:
a type of spinal cord neuron that project to the parabrachial nucleus (PBN) in the brain
SPBNs receive input from other neurons in the spinal cord, including
Neurotransmitters can be either excitatory or inhibitory, with excitatory neurotransmitters promoting nerve firing and inhibitory ones reducing it
excitatory
Glutamate is the primary excitatory neurotransmitter in the central nervous system, playing a crucial role in learning and memory
Acetylcholine is excitatory at the neuromuscular junction, causing muscle contractions
Norepinephrine and dopamine are also excitatory, with roles in arousal, alertness, and motivation
Norepinephrine acts as both a neurotransmitter, transmitting signals between nerve cells, and a hormone, influencing bodily functions
Neurotransmitters are chemical messengers in the body that allow neurons (nerve cells) to communicate with each other and other cells. They transmit signals, or messages, across the synapse, the tiny gap between neurons or between neurons and other cells
Dopamine is a neurotransmitter in the brain, often called the "feel-good" hormone, involved in the reward system, motivation, and movement
Other excitatory neurotransmitters include
serotonin:
Serotonin is synthesized from the amino acid tryptophan.
Tryptophan is an essential amino acid
a polar aromatic amino acid:
Tyrosine (Tyr):
Contains a hydroxyl group (-OH) on its aromatic ring, allowing it to participate in hydrogen bonding
Tryptophan (Trp):
Has a complex indole ring structure that includes a nitrogen atom, making it polar and capable of hydrogen bonding
the precursor to serotonin and melatonin. Its structure consists of an α-amino group:
an α-carboxylic acid group
and a unique indole side chain
making it a polar molecule
with a non-polar aromatic beta carbon substituent
epinephrine:
Epinephrine is both a neurotransmitter and a hormone, but it acts mainly as a hormone. Epinephrine, also known as adrenaline, plays an important role in your body's fight-or-flight response
histamine:
Histamine is released by mast cells and basophils in response to allergens, pathogens, or injury, triggering an immune response
glycine:
Glycine is a key inhibitory neurotransmitter, particularly in the spinal cord and brainstem, playing a crucial role in motor and sensory functions. It also contributes to the function of excitatory neurotransmitter:
NMDA receptors:
a glutamate receptor and a crucial ion channel in neurons. It plays a significant role in synaptic plasticity, memory formation, and learning
particularly during development
Excitatory neurotransmitters, like glutamate, bind to receptors on the postsynaptic neuron's membrane, triggering depolarization and increasing the likelihood of an action potential
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inhibitory interneurons:
Inhibitory interneurons are neurons that release inhibitory neurotransmitters
Inhibitory neurotransmitters are chemicals that reduce the likelihood of a nerve cell firing and sending signals. These neurotransmitters act as "off switches," calming the nervous system and preventing excessive stimulation
primarily GABA, to suppress the activity of other neurons
GABA reduces neuronal excitability and can produce a calming, relaxing sensation
GABA is involved in controlling nerve cell activity, particularly those associated with anxiety, stress, and fear
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Corticofugal projection neurons:
They connect the cerebral cortex to subcortical areas, forming tracts like the corticothalamic, corticostriatal, corticorubral, corticotectal, corticobulbar, and corticospinal tracts
Callosal projection neurons:
also known as interhemispheric commissural pyramidal neurons, are specialized neurons that connect the two cerebral hemispheres via the corpus callosum, the largest white-matter tract
Modulatory projection neurons:
a type of neuron that extends axons to distant regions of the central nervous system (CNS) and exert modulatory (metabotropic) effects on target neurons, often alongside more traditional (ionotropic) actions
associative projection neurons:
neurons that project their axons within the same hemisphere to connect different cortical areas
commissural projection neurons:
Commissural projection neurons establish connections between the two sides of the brain, allowing for communication and coordination between them
corticofugal projection neurons:
are involved in the formation of several important brain circuits, including the corticothalamic, corticostriatal, corticorubral, corticotectal, corticobulbar, and corticospinal tracts
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peripheral sensory neurons
a type of neuron that detects stimuli in the body and transmits them to the central nervous system.
These neurons are located in the peripheral nervous system (PNS) and play a crucial role in various bodily functions, including sensing external stimuli, maintaining homeostasis, and even regulating the immune system
Primary afferent fibers: These neurons receive sensory input from the body
They receive sensory information from various receptors in the body:
mechanoreceptors
sensory receptors that respond to mechanical stimuli
Cutaneous Mechanoreceptors:
These are located in the skin and include:
Meissner's corpuscles:
specialized nerve endings in the skin, responsible for detecting fine touch, low-frequency vibrations, and the sensation of flutter
They are rapidly adapting receptors, meaning they respond best to changes in stimulus rather than sustained pressure
Pacinian corpuscles:
Pacinian corpuscles are rapidly adapting mechanoreceptors that detect vibration and deep pressure
Merkel's disks:
They are composed of Merkel cells and associated Aβ-afferent nerve endings
Ruffini's corpuscles:
encapsulated nerve endings
thermoreceptors
Thermoreceptors help the body regulate its temperature by sending information about the surrounding temperature to the brain's hypothalamus, which acts as the body's "thermostat"
nociceptors
specialized sensory nerve endings that detect potentially harmful stimuli, alerting the brain to the risk of injury or damage and initiating pain perception
chemoreceptors
specialized sensory cells that detect and respond to chemical stimuli in the environment or within the body, triggering a response
Peripheral Chemoreceptors:
Found in the carotid bodies and aortic arch, these receptors primarily detect changes in blood oxygen, carbon dioxide, and pH. They send signals to the brainstem to regulate breathing and blood pressure
Central Chemoreceptors:
Located in the brainstem, these receptors respond to changes in the concentration of hydrogen ions (H+) in the cerebrospinal fluid, effectively detecting changes in blood carbon dioxide
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Interneurons
connecting primary afferent fibers to projection neurons
They outnumber both sensory and motor neurons
They act as a "middleman" between sensory neurons (afferent) and motor neurons (efferent), and also connect to other interneurons, forming intricate neural circuits
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