Test Answers on Neurochemistry Terms – Flashcards
Unlock all answers in this set
Unlock answersquestion
what is neuroplasticity
answer
the brain's ability to reorganize itself by forming new connections between dendrites; changes in the spine/thorn morphology of the dendrites are associated with learning and memory.
question
What is the function of the hypothallamus?
answer
Responsible for regulating basic biological needs: hunger, thirst, temperature control
question
what is the function of the cerebrum?
answer
aka the cerebral cortex, which is the outer later of grey matter; responsible for sensing, thinking, learning, emotion, consciousness and voluntary movement.
question
what is the function if the corpus callosum
answer
bridge of fibers passing information between the two cerebral hemispheres
question
what is the function of the thalamus ?
answer
the relay center for the cerebral cortex/cerebrum; handles incoming and outgoing signals
question
what is the function of the hippocampus?
answer
part of the limbic system involved in learning and memory
question
what is the function of the pituitary gland?
answer
The pituitary gland is the master gland that regulates other endocrine glands. The pituitary gland releases oxytocin and vasopressin
question
what is the function of the pons?
answer
The pons is involved in sleep and arousal
question
what is the function of the midbrain?
answer
The midbrain controls Eye movement and auditory and visual reflexes
question
what parts of the brain make up the brainstem
answer
The brainstem is made up of the pons, medulla and midbrain
question
what is the function of the limbic system and what parts of the brain does it include?
answer
The limbic system is made up of the amygdala the thalamus, the hypothalamus and the hippocampus. The limbic system is the emotional brain which is concerned with behavior and emotional expression as well as learning and memory processes
question
what is the function of the medulla
answer
The medulla is responsible for regulating largely unconscious functions such as breathing and circulation
question
what is the function of the reticular formation
answer
The reticular formation is a group of fibers that carry stimulation related to sleep and arousal through the brainstem. the reticular formation serves as a filter and is inhibited by psychedelics
question
what is the function of the spinal cord
answer
The spinal cord is responsible for transmitting information between the brain and the rest of the body. the spinal cord handles simple reflexes
question
what is the function of the cerebellum
answer
The cerebellum is the structure that ordinates fine muscle movement and balance
question
what is the amygdala
answer
The amygdala is the part of the limbic system involved in emotion and aggression
question
what is the function of the central nervous system and what makes up the central nervous system
answer
The CNS is made up of the brain and spinal cord. the central nervous system functions as an integrative (spinal cord) and control (brain) center
question
what is the function of the peripheral nervous system and what does it include
answer
The peripheral nervous system allows for communication between the central nervous system and the rest of the body. The cranial and spinal nerves make up the peripheral nervous system; the peripheral nervous system contain ganglia.
question
what are the two branches of the peripheral nervous system
answer
The peripheral nervous system includes the autonomic nervous system and the somatic nervous system
question
what is the autonomic nervous system
answer
The autonomic nervous system is the visceral motor system and controls involuntary nervous movements. The autonomic nervous system conducts impulses from the central nervous system to cardiac muscles smooth muscles and glands
question
what is the somatic nervous system
answer
The somatic motor system is the voluntary motor system. It conducts impulses from the central nervous system to the skeletal muscles
question
what are the two divisions of the autonomic nervous system? Is there a third?
answer
The autonomic nervous system is divided into the sympathetic division and the parasympathetic division however there is also an enteric division
question
describe the sympathetic division
answer
The sympathetic division is part of the autonomic nervous system of the peripheral nervous system. The sympathetic division controls fight or flight responses and mobilizes the body system during activity
question
describe the parasympathetic division
answer
The parasympathetic division is a division of the ANS of the PNS. The parasympathetic division controls rest and digest reflexes. It conserves energy, and promotes housekeeping functions during rest
question
describe the enteric division
answer
the enteric division is part of the autonomic nervous system. There are two types of neurons in the enteric division. Sensory neurons are neurons that control mechanical and chemical conditions. Motor neurons control peristaltic contractions. The enteric division is part of the gut
question
what are the six primary responses of the parasympathetic nervous system
answer
1. stimulates flow of saliva 2. lowers the heartbeat 3. constricts bronchi 4. stimulates peristalsis and secretion 5. stimulates release of bile 6. contracts bladder
question
what are the seven main function of the sympathetic nervous system
answer
1. Dilate pupils 2. inhibits flow of saliva 3. accelerates heartbeat 4. dilates bronchi 5. inhibits peristalsis and secretion 6. conversion of glycogen to glucose 7. secretion of adrenaline and noradrenaline 8. inhibits bladder contraction
question
what does the occipital lobe control
answer
vision
question
what does the cerebellum control
answer
balance and coordination
question
what does afferent mean
answer
neurons that carry signals to the central nervous system for processing. For example sensory neurons
question
what did efferent mean
answer
neurons they carry signals from the central nervous system to the peripheral nervous system or two peripheral tissue. These neurons create a response
question
what is a sensory neuron
answer
an afferent neuron; the connects impulses from receptors to the sensory nervous system, impulses include touch, pain, heat, etc.
question
what is a motor neuron
answer
an efferent neuron that conducts impulses from the CNS to effector organs i.e. muscles
question
what are the three main components of a neuron
answer
The cell body or soma, the dendrites, and the axon
question
describe the cell body. what are the main functions of the cell body?
answer
the cell body is the control center of the neuron; it contains organelles and a phospholipid bilayer with integral proteins; the cell body makes proteins for other parts of the neuron.
question
describe the phospholipid bilayer
answer
the phospholipid bilayer is a powerful insulator that contains many proteins, which are electronically active, such as the voltage gated ion channels.
question
what are dendrites?
answer
dendrites receive incoming singles; they are branch like structures that protrude from the cell body and collect incoming signals from other neurons and transfer them to the soma
question
what are dendritic spines?
answer
dendritic spines, or thorns, are small membrane protrusions of a neurons's dendrite that receive input.
question
describe the axon
answer
the axon transmits the outgoing electrical signal from the integration center to the end of the axon; axons can vary in length and can branch out, which are called axon "collaterals" or "branches.'
question
what are the three segments of an axon?
answer
the axon hillock, the axon proper and the axon terminal
question
what is the axon hillock?
answer
the axon hillock is the initial portions that comes out of the cell body - called the axon initial segment - where the action potential (aka nerve signal) is initiated
question
what is the axon proper?
answer
the axon proper is the middle segment of the axon
question
what is the axon terminal?
answer
the axon terminal, aka the presynaptic terminal, is the terminal where the axon meets its target; houses NT and can contain 40-50 synaptic vessicles
question
what is long term potentiation?
answer
long term potentiation is a long lasting enhancement in signal transmission (interneuronal communication) affected by dendritic spines and an increase in interneuronal connections
question
what is long term depression?
answer
long term depression is a reduction in the efficacy of neuronal synapses; LTD is one of several processes that serves to selectively weaken specific synapses in order to make constructive use of synaptic strengthening caused by LTP. This is necessary because, if allowed to continue increasing in strength, synapses would ultimately reach a ceiling level of efficiency, which would inhibit the encoding of new information
question
what are the three types of neurons?
answer
sensory neurons (afferent), motor neurons (efferent), and interneurons
question
describe interneurons
answer
interneurons are responsible for the coordination and integration of sensory input and motor output, entirely in the central nervous system, except enteric interneurons
question
what is a preganglionic neuron?
answer
fibers from the central nervous system to the ganglion; the cell body is located in the central nervous system (brain stem or spinal cord) and the preganglionic neuron makes synaptic connections in the ganglia.
question
what are the ganglia?
answer
ganglia are aggregates of nerve cell bodies in the peripheral nervous system
question
what is the neurotransmitter at the preganglionic synapse?
answer
acetylcholine
question
what is the neurotransmitter at the post-ganglionic synapse for parasympathetic response? sympathetic response?
answer
parasympathetic = acetylcholine, rest and digest sympathetic = norepinephrine and epinephrine and acetylcholine
question
diagram autonomic pathways
answer
CNS -preganglionic neuron ->Autonomic ganglion -postganglionic neuron -> Target tissue NT are released from the preganglionic neuron (ACh) and the postganglionic neuron (ACh, NE, E)
question
what are glial cells?
answer
glial cells are non neuronal cells. they are any cells that do not directly participate in synaptic interactions and electrical signaling, but have supportive functions for it and help define and maintain the signaling abilities of a neuron; they help hold our nervous system together functionally and they outnumber neurons.
question
what is a synapse
answer
the site of interneuronal communication
question
what is a neurotransmitter?
answer
the chemical messenger for interneuronal communication
question
what is a myelinated axon?
answer
allows nerve impulses to transmit faster; axon is covered in a myelin sheath made up of lipids, proteins, and sphingolipids produced by cells called schwann cells
question
what is a myelin sheath? what are the 3 things that make up the myelin sheath?
answer
helps speed up the signal, prevents loss of signal, aids in signal transmission, prevents ion leakage; lipids are cholesterol, sphingomyelin and cerebroside; made up of 75% lipid and 15% protein
question
what are the nodes of ranvier?
answer
the tiny segments of the axon that are exposed after wrapping up of the axon by the schwann cells; we see a high concentration of voltage-gated sodium channels at the nodes of ranvier; excitable patches of the membrane; contain large amount of Nav, Kv, and Na/K-ATPases
question
what is the resting cell potential? intracellular ion?
answer
-70mV, K
question
what is white matter?
answer
myelinated neurons
question
what is grey matter?
answer
nerve cell bodies and dendrites; unmeylinated axons
question
what are schwann cells?
answer
these make up the myelin sheath for the axon, which insulate axons to form white matter; in the PNS
question
what are satellite cells?
answer
nonmyelinating schwann cells, encapsulate neurons and form supporting capsules around them; in the PNS
question
what are the two types of glia cells in the PNS?
answer
schwann cells and satellite cells
question
what are the four types of glia in the CNS?
answer
oligodendrocytes; astrocytes; microglial cells; ependymal cells
question
what are oligodendrocytes?
answer
CNS analogy to Schwann cells; form myelin sheaths around the axons of the CNS
question
what are astrocytes? what are their three main functions?
answer
starlike, highly branched cells in CNS; make up ½ of the cells in the brain, 3 main functions: i) take up and release chemicals; ii) take up extracellular K+; iii) feet-like structures surround the blood brain barrier and tighten the barrier, which helps protect the brain from chemical trauma
question
what are microglial cells?
answer
macrophages; immune system cells, help digest dead neurons and engulf and digest cellular debris, in CNS
question
what are ependymal cells?
answer
neural stem cells; help circulate spinal fluid and produce cerebral spinal fluid (CSF)
question
what is the blood brain barrier? what can pass through it?
answer
serves to protect the brain from chemical injury and is a highly selective barrier that separates the blood vessels from the brain's extracellular fluid; allows for passage of gases, water and lipophilic molecules
question
what is "potential"?
answer
a measure of how badly one area of charge is attracted to another (volts), RMP is -70 millivolts
question
what is the membrane potential?
answer
inside charge (V) - outside charge (V)
question
what is depolarization?
answer
an event that makes the intracellular space more positive, and decreases the membrane potential, caused by an influx of positive ions
question
what is hyper polarization?
answer
an event that makes the intracellular space more negative, and increases the membrane potential, caused by an outflux of positive ions or an influx of chloride
question
what are ion channels?
answer
transmembrane and integral proteins that allow ions to pass from one side of the lipid membrane to the other
question
what are gated channels?
answer
a specific action initiates the opening or closing of the channel, and that action usually precedes the name (i.e. a voltage gated channel, whose gate is opened or closed based on the membrane potential in volts)
question
what are leak channels?
answer
not gated; continuously open and allow ions to leak across the membrane; ions flow with the concentration gradient and you find these types of channels all over the neuron
question
what is the action potential?
answer
rapid electrical signals that travel undiminished in amplitude (strength) from the cell body to axon terminal; a depolarizing stimulus causes the membrane potential to rise to -55 mV, the threshold potential, and Nav open, causing an influx of Na ions; the cell depolarizes due to the influx of Na, and eventually Nav closes, while Kv opens and K moves out of the cell; the outflux of K causes a repolarization of the membrane, and Kv channels are slow to close, causing hyperpolarization, until the leak channels and Na/K-ATPase cause the return to RMP
question
what are ion gated channels?
answer
opening and closing is affected by the intracellular concentrations of ions
question
what are ligand gated ion channels?
answer
bind chemicals (i.e. ligands, NT or structural analogs) to extracellular receptors, causing opening or closing of channels
question
what are voltage gated sodium channels? what potential causes them to open? close?
answer
voltage gated sodium channels; open at the threshold potential of -55 mV and close at the action potential of +30 mV; cause Na ions to rush into the cell
question
what are voltage gated potassium channels? what potential causes them to open? close?
answer
voltage gated potassium channels; open at the action potential of +30 mV, allow K ions to rush out of the cell, would close at RMP, but are initially slow to close, so they will stay open until about -80 mV, but the leaky K channels and Na/K-ATPase will bring the cell back to RMP and the Kv will close
question
what is saltatory conduction?
answer
the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon; the action potential is said to "jump" from node to node through the myelinated axon, but really it is diffusion of the sodium ions
question
what is inactivation
answer
something comes in and physically blocks the pore
question
what is deactivation?
answer
has to do with voltage and the channel requires reactivation, usually deactivation occurs when the voltage sensor has been reset during repolarization
question
what is chemical transmission?
answer
the major means by which neurons communicate with one another
question
what is signal transduction?
answer
a mechanism or phenomenon that converts a mechanical or chemical stimulus into a particular cellular response, i.e. the activation of an enzyme, the expression of a protein, or depolarization or hyper polarization; facilitated by receptors
question
what is a receptor?
answer
transmembrane protein that accepts signal (extracellularly) and communicates it to the inside of the cell
question
what is a ligand?
answer
the chemical or molecule that binds to the extracellular side of a receptor, i.e. a neurotransmitter in ionotropic receptors or a g-protein in metabotropic receptors
question
what are ionotropic receptors?
answer
i.e. ligand gated ion channel receptors, which bind agonists, resulting in the opening of Na, K and Cl ion channels, resulting in depolarization or hyperpolarization
question
what are metabotropic receptors?
answer
i.e. g-protein coupled receptors, coupled to a g-protein, so these receptors act on a g-protein when the g-protein agonist binds; cellular response is dictated by the g-protein the receptor is coupled to
question
what are agonists?
answer
ligands that, upon binding, cause the desired cellular response
question
what are direct agonists?
answer
bind to desired receptor and/or elicit a response
question
what are indirect agonists
answer
does not bind directly to a receptor but still results in the desired response, or release of NT (i.e. it may block reuptake of a NT or prevent the breakdown of a NT)
question
what are inverse agonists?
answer
bind to receptor but elicits the opposite cellular response
question
what are antagonists
answer
ligands that bind to receptor but do not cause a change in basal level activity of the cell; counteract the affect of the agonists
question
what are competitive antagonists
answer
compete with an agonist for the same receptor
question
what are noncompetitive antagonists
answer
bind to allosteric site and weaken the agonists binding affinity
question
what is synaptotagmin?
answer
a calcium sensing protein located on the SV
question
what is synaptobrevin? it's alternative?
answer
synaptobrevin is a vesicle associated membrane protein, alternative is VAMP
question
what is syntaxin?
answer
a tSNARE protein on presynaptic membrane
question
what is SNAP-25
answer
a tSNARE protein on presynaptic membrane
