Chapter 2: Neurons & Glia Flashcards
A cell that is specialized for the transmission of information and characterized by long fibrous projections called axons, and shorter, branch-like projections called dendrites; the basic functional unit of the nervous system; also called a nerve cell
Neuron
A type of cell that provides physical and chemical support to neurons and maintain their environment; contributes to brain function mainly by insulating , supporting, and nourishing neighboring neurons.
Glial cell
The idea that individual cells called neurons transmit signals in the nervous system, and that these cells are not continuous with other cells as proposed by nerve net theory.
The Neuron Doctrine
the microscopic study of tissues and organs through sectioning, staining, and examining those sections under a microscope.
Histology
Stains nucleic acids, mainly RNA on rough endoplasmic reticulum; uses a variety of dyes to show charged structures (Nissl bodies) in the soma of neurons and glia.
Nissl stain
the study of the structural arrangement of neurons within the central nervous system.
Cytoarchitecture
describes the way certain tissues, such as bone membrane, skin, or brain tissues, are arranged in layers.
Laminar Structure
Soaking brain tissue in a silver chromatic solution; makes a small percentage of neuron become darkly colored in their entirety.
Golgi stain
Theory that neutrites of different cells are fused into a continuous reticulum (nerve net); permits bi-directional informational flow.
Golgi (Reticular) Theory
Aka Soma or perikaryon; the core section of the neuron. It contains genetic information, maintains the neuron’s structure, and provides energy to drive activities.
Cell Body
Small processes on developing neurons that ultimately grow out into axons OR dendrites under the control of growth stimulating or inhibiting factors from their direct extracellular environment sensed by receptors in the growth cone.
Neurite
carry electrical impulses that are the means of communication within the brain and between the brain and the rest of the body; The long portion of a neuron that conducts impulses away from the body of the cell
Axon
a thin fiber that extends from a nerve cell. Its job is to pass along electric signals it receives from other cells.
Dendrite
Proteins that regulate the transcription of genes; proteins involved in the process of converting, or transcribing, DNA into RNA.
Transcription Factor
Molecules that combine to form proteins. These molecules and proteins are the building blocks of life.
Amino Acid
The process through which information encoded in messenger RNA (mRNA) directs the addition of amino acids during protein synthesis; takes place on ribosomes in the cell cytoplasm, where mRNA is read and translated into the string of amino acid chains that make up the synthesized protein.
Translation
The entire set of DNA instructions found in a cell; contains all the information needed for an individual to develop and function.
Genome
An intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell. It reads the messenger RNA (mRNA) sequence and translates that genetic code into a specified string of amino acids, which grow into long chains that fold to form proteins.
Ribosome
Has on it ribosomes, which are small, round organelles whose function it is to make those proteins; involved with the production, folding, quality control and despatch of some proteins.
Rough Endoplasmic Reticulum
(Rough ER)
A group of ribosomes bound to an mRNA molecule like “beads” on a “thread”. It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.
Polyribosome
Does not have ribosomes on its surface; Synthesizes lipids, phospholipids as in plasma membranes, and steroids. It regulates internal Ca^2+ concentration.
Smooth Endoplasmic Reticulum
(Smooth ER)
A cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.
Golgi Apparatus
Are membrane-bound cell organelles (mitochondrion, singular) that generate most of the chemical energy needed to power the cell’s biochemical reactions. Chemical energy produced by this cell organelle is stored in a small molecule called adenosine triphosphate (ATP).
Mitochondria
An important “energy molecule”; captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes.
ATP (Adenosine Triphosphate)
Composed of a lipid bilayer that has hydrophilic (water loving) and hydrophobic ends; the site where most processes involved in neuronal preservation and functioning are triggered.
Neuronal Membrane
Carries out three broad functions: it spatially organizes the contents of the cell; it connects the cell physically and biochemically to the external environment; and it generates coordinated forces that enable the cell to move and change shape; 3 bones: microtubules (tubulin), Neurofilaments (intermediate filaments), Microfilaments (actin).
Cytoskeleton
Are major components of the cytoskeleton. They are Large (~20nm) and They are composed of tubulin, runs down the neutrites to give basic shape, and acts as a “railroad” for transport proteins. They are found in all eukaryotic cells, and they are involved in mitosis, cell motility, intracellular transport, and maintenance of cell shape. PROMINENT IN AXONS!
Microtubules
Assist with cell movement and are made of a protein called actin. They are small (~5nm), its function is dynamic, involved in growth and movement, and enriched in spines. Actin works with another protein called myosin to produce muscle movements, cell division, and cytoplasmic streaming. They keep organelles in place within the cell.
Microfilament (Actin)
Functions as maintenance and support of the cytoskeleton. Ones that are phosphorylated are transported down into the axon, where they maintain the size and caliber of the axon. Ones that are unphosphorylated remain in the cell body serving their function there. They control thickness of neutries, enriched in AXONS, and is rope-like.
Neurofilament (Intermediate Filament)
The neuronal region in the cell body wherein the summation of the excitatory & inhibitory activity occurs; It is where the neuronal action potential is usually created. It is a cone-shaped area in the neuronal cell body from where the axon originates.
Axon Hillock
Allows individual neurons to make contacts with multiple neurons within a target and with multiple targets.
Axon Collateral
small swellings that are found at the terminal ends of axons; They are typically the sites where synapses with other neurons are found, and neurotransmitters are stored there to communicate with other neurons via these synapses.
Axon Terminal
Terminal inflated portion of the axon, containing the specialized apparatus necessary to release neurotransmitters; The small knobs at the end of an axon that release chemicals called neurotransmitters. They form the Presynaptic Neuron of the synapse.
Terminal Bouton
Transmits nerve impulses between two nerve cells (neurons) or between a neuron and muscle cell. Their gap connect one neuron to another and are thus responsible for the transmission of messages from the nerves to the brain and vice versa. It has 2 parts: presynaptic and postsynaptic.
Synapse
A complex branching pattern found at axonal terminals that innervates the target tissue; here, the impulses are transmitted to other nerve cells or to effector organs.
Terminal Arbor
An important pathway of communication by and with the CNS
Innervation
Play the central role in synaptic transmission. They are regarded as key organelles involved in synaptic functions such as uptake, storage and stimulus-dependent release of neurotransmitter
Synaptic Vesicle
Everything contained within the confines of the cell membrane; provides shape to the cell. It fills up the cells thus enabling the organelles to remain in their position.
Cytoplasm
A number of membrane-enclosed structures; the nucleus, Rough ER, golgi apparatus, and mitochondria.
Organelle
Watery fluid inside the cell; a salty, potassium-rich solution that is separated from the outside by the neuronal membrane; contains dissolved nutrients, helps break down waste products, and moves material around the cell.
Cytosol
Houses the cell’s genome, it serves both as the repository of genetic information and as the cell’s control center. DNA replication, transcription, and RNA processing all take place within it, with only the final stage of gene expression (translation) localized to the cytoplasm.
Nucleus
Threadlike structures made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell.
Chromosome
Carries genetic information which is read in cells to make the RNA and proteins by which living things function.
DNA (Deoxyribonucleic Acid)
The basic physical and functional unit of heredity. They are made up of DNA
Gene
The process by which the information encoded in a gene is turned into a function.
Gene Expression
Are large, complex molecules that play many important roles in the body. They are critical to most of the work done by cells and are required for the structure, function and regulation of the body’s tissues and organs; final product of gene expression in the synthesis of molecules.
Protein
The assembly of protein molecules, occurs in the cytoplasm; the creation of proteins by cells that uses DNA, RNA, and various enzymes.
Protein Synthesis
It tells your DNA how to make specific proteins. It contains instructions that your body can read to create a special type of protein; carry protein information from the DNA in a cell’s nucleus to the cell’s cytoplasm (watery interior), where the protein-making machinery reads its sequence and translates each three-base codon into its corresponding amino acid in a growing protein chain.
mRNA (messenger
ribonucleic acid)
The process of assembling a piece of mRNA that contains the information of a gene. The resulting mRNA is the TRANSCRIPT.
Transcription
A region of DNA upstream of a gene where relevant proteins (such as RNA polymerase and transcription factors) bind to initiate transcription of that gene. The resulting transcription produces an RNA molecule (such as mRNA).
Promoter
Space between the presynaptic and postsynaptic membranes; provide space for chemical transmission of messages from the nervous system.
Synaptic Cleft
Transfer of info at the synapse from one neuron to another; the process by which one neuron communicates with another. Information is passed down the axon of the neuron as an electrical impulse known as action potential.
Synaptic Transmission
Chemical signal; stored in and released from the synaptic vesicles within the terminal. Their job is to carry chemical signals (“messages”) from one neuron (nerve cell) to the next target cell.
Neurotransmitter
Movement of material down the axon; The process whereby motor proteins actively navigate microtubules to deliver diverse cargoes, such as organelles, from one end of the axon to the other; highly specialized functions like neurogenesis, synaptogenesis, and plasticity.
Axoplasmic Transport
Degeneration of axons that occurs when they are cut.
Wallerian Degeneration
Movement of material from the Soma to the axon terminal; uses kinesin.
Anterograde Transport
Movement of material from the axon terminal to the soma; uses dynein.
Retrograde Transport
ATP-dependent motor proteins that can generate force and displacement along microtubules.
Kinesin
Primary motor responsible for motility and force generation toward the minus ends of microtubules
Dynein
Dendrites of a single neuron; a branched protoplasmic extension of a nerve cell that propagates the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.
Dendritic Tree
Specialized protein molecules that detect the neurotransmitters in the synaptic cleft; proteins either inside a cell or on its surface which receive a signal.
Receptor
Serves as a storage site for synaptic strength and help transmit electrical signals to the neuron’s cell body.
Dendritic Spine
These neurons have a single long axon that is responsible for sending electrical signals. The axon in these neurons is myelinated, which allows for rapid signal transmission.
Unipolar Neuron
These neurons preserve the tonotopic map for relay to the cochlear nuclei and then throughout the ascending auditory pathway. They also encode intensity by their discharge rate. Cell bodies of cochlear ________ neurons lie within the spiral ganglion, named for the shape of the cochlea.
Bipolar Neuron
These neurons can transfer the most information between cells, and they are the most common form of neuron in the human nervous system.
Multipolar Neuron
Comprises various tightly controlled, complex circuits throughout the body that allows for both voluntary and involuntary movements through the innervation of effector muscles and glands.
Motor Neuron
They carry sensory information and regulate motor activity.
Interneuron
A subtype of glial cells that make up the majority of cells in the human central nervous system (CNS). They perform metabolic, structural, homeostatic, and neuroprotective tasks such as clearing excess neurotransmitters, stabilizing and regulating the blood-brain barrier, and promoting synapse formation.
Astrocyte
The myelinating cells of the central nervous system (CNS) that allow the fast and efficient transfer of neuronal communication through the myelination of axons; one cell can myelinate several axons.
Oligodendroglial cell
plays a vital role in maintaining the peripheral nervous system (PNS); This cell forms a myelin sheath by wrapping its plasma membrane concentrically around the inner axon. One cell myelinates a single axon.
Schwann cell
Protects the axons and helps speed nerve transmissions.
Myelin
Allow for ions to diffuse in and out of the neuron, propagating the electrical signal down the axon; Since they are spaced out, they allow for saltatory conduction, where the signal rapidly jumps from node to node.
Node of Ranvier
are neuroepithelial multiciliated cells lining the spinal cord and cerebral ventricles; play key roles in mammalian CNS development and normal physiological processes by controlling the production and flow of cerebrospinal fluid (CSF), brain metabolism, and waste clearance.
Ependymal Cell
the most prominent immune cells of the central nervous system (CNS) and are the first to respond when something goes wrong in the brain; play important roles in brain infections and inflammation.
Microglial Cell
A process that removes the intervening, non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein.
RNA Splicing
Polar/ water loving
Hydrophilic
non-polar/ scared of water
Hydrophobic
A protein that helps stabilize the internal skeleton of nerve cells (neurons) in the brain; stabilizes axonal MTs by interacting with tubulin.
Tau
A brain condition thought to be linked to repeated head injuries and blows to the head; due to repetitive head trauma and accumulation of p-tau.
Chronic traumatic encephalopathy (CTE)
Converts physical stimuli into electrical; carries information about changes in external and internal environments to the central nervous system (CNS).
Sensory Neurons
Has stellate cells and pyramid cells
Soma
