Nervous System Flashcards
what are the three regions of the neural tube in a developing fetus?
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
Name the brain region in the neural tube
the ____ is responsible for much of what we associate with behavior and personality, and develops into the diencephalon – which contains the thalamus, hypothalamus, and pineal & pituitary glands – as well as the telencephalon – which contains the cerebrum
Prosencephalon (forebrain)
the limbic system includes…
- hypothalamus
- hippocampus
- thalamus
- amygdala
the ____ is the largest structure in the brain which contains the cerebral cortex
cerebrum
region of cerebral cortex associated with higher level cognition and executive functions
frontal lobe
region of cerebral cortex involed in sensory processing/perception
parietal lobe
region of cerebral cortex that has prominet roles in sound and language processing, as well as memory consolidation. This region also contains the** limbic system**, which plays a role in emotions and emotional memory formation
temporal lobe
primary visual cortex
occipital lobe
sometimes referred to as the 5th cortex of the brain, this region is deep within the cerebrum and takes in auditory, olfactory, gustatory, visual, and somatosensory cues via thalamic and horizontal cortical afferents from inside the body (also known as interoception) to determine the senses we perceive
insula
“old brain” associated with functions that have been highly conserved throughout evolution. Includes the cerebellum, pons, and medulla
hindbrain
relays signals between the cerebellum, medulla and the rest of the brain. Involved in sleep, respiration, swallowing, taste, bladder control, and balance
pons
associated with autonomic functions i.e breathing, heart rate, and blood pressure
medulla
area of hindbrain associated with coordinated movement
cerebellum
topmost part of the brainstem, the connection central between the brain and the spinal cord. Serves important functions in motor movement, homeostatic regulation, sleep, and in auditory and visual processing.
midbrain
region of brainstem associated with processing auditory signals and sending them to the medial geniculate nucleus in the thalamus
inferior colliculus
part of midbrain that processes visual signalls and participates in control of eye movements
superior colliculus
part of midbrain that facilitaties coordination of voluntary motor control
substantia nigra
the midbrain, together with the medulla and pons are collectivelly referred to as the ______
brainstem
forms a stem that connects brain to the spinal cod
processes memory, emotions, and decision-making.
aka fear center of the brain
amygdala
responsible for the consolidation of short term memory into long term memory
hippocampus
links the nervous system to the endocrine sysem via the pituitary gland
hypothalamus
modulates sleep through melatonin production
pineal gland
projection through which the hypotalamus secretes oxytocin and ADH (vasopressin)
posterior pituitary
part of reward pathway
septal nuclei
relays sense and motor signals and regulates sleep and alertness
post office of the brain
thalamus
spinal region that corresponds with the neck and contains sevel cervical vertebrae, C1-C7
cervical spine
spinal region that corresponds with the curve of the upper back and contains 12 vertebrae, T1-T12
thoracic spine
spinal region that corresponds with the lower back and has 5 vertebrae, L1-L5
lumbar spine
forms sacrum in adulthood, but throughout development is divided into 5 vertebrae, S1-S5
sacral vertebrae
the vertebral column ends with the …
coccyx (tailbone)
neurons that arise from the central nervous system and supply the ganglia
preganglionic neuron
in the parasympathetic system, preganglionic neurons are long, synapsing on ganglia near or on the target organ. In the sympathetic system, they are much shorter and go to sympathetic trunk
neurons that arise from the ganglia and supply the tissues.
postganglionic neurons
chain of ganglia near the spinal cord that extends approximatelt from the base of the skull to the coccyx. Preganglionic neurons with synapse with Postganglionic neurons here
sympathetic trunk
pre and postganglionic fibers of the parasympathetic system, as well as preganglionic fibers of the sympathetic nervous system primarily use what neurotransmitter?
acetylcholine
postganglionic sympathetic fibers mostly use what neurotransmitter?
Norepinephrine
pg. 131 biology NS
the planning of motor control is initiated in the ____ and executed by the ___
premotor cortex, primary motor cortex
the electrochemical signals generated by the primary motor cortex will propogate down the spinal cord after being modulated by ____ and _____
cerebellum and basal ganglia
this modulation helps coordinate the contractions of multiple muscle groups together into a unified, directed movement
what neurotransmitter is associated with muscle coordination, and the dysregulation of which is implicated in diseases of fine motor control deterioration such as Parkinson’s?
Dopamine
the main excitatory neurotransitter that is rsponsible for depolarization and the elicitation of action potentials
glutamate
the most common NT!
the main inhibitory NT responsible for hyperpolarizing neurons, reducing their likelihood of firing. Associated with many of the physioogical effects of alcohol intoxication
GABA
____ are the subtype of glial cells that form the blood-brain barrier (along with epithelial cells). Their other roles include detoxification, provision of nutrients, and recovery from injury.
Astrocytes
Name the glial cell with the respective functions
- insulin-dependent active transport of glucose from the bloodstream
- detoxification
- providing nutrients
- injury recovery
astrocytes
Name the glial cell
provide myelination in the CNS
oligodendrocytes
Provide myelination in the PNS
Schwann cells
True or False
All neurons are myelinated
False
Name the primary functions of myelination
- speeding up the transmission of action potentials
- preventing cross-talk between axons
Name the glial cell
perform an immune function and act similar to macrophages. They clean out microbes and debris (i.e waste and damaged cells, extracellular protein deposits, neuron pruning) in the CNS
microglia
Name the glial cells
CSF is secreted by ___
ependymal cells
cerebrospinalfluid provides a more constant, stable chemical environment and physically cushions the CNS
difference in electric potential (difference is distribution of charged ions) on each side of the cell membrane
membrane potential
if there are more positively charged particles on the outside of a cell than on the inside of a cell, is the membrane potential negative or positive?
Negative
this reflects the lack of positive charge inside of the cell
the intracellular environment is rich in ____, and relatively poori ____, ____, and _____
the intracellular environment is rich in K+, and relatively poori Na+, Cl, and Ca2+
Na+/K+ ATPase is a transmembrane ion transporter that plays a key role in regulating membrane potentials. Another name for this transporter is….
sodium-potassium pump
Na+/K+ ATPase is an enzyme that hydrolyzes ATP to pump ____ sodium ions at a time outside of the cell while bringing in ____ potassium ions
3 Na+ ions outside the cell, 2 K+ ions inside
the sodium potassium pump stabalizes at a resting potential of ____
-70mV
any changes in the sodium-potassium pump that destabilize the -70mV potential difference by bringing it close to 0mV results in ______
depolarization
the cellular process that occurs in response to changes making the membrane potential difference more negative
hyperpolarization
makes cell potential more positive
the small space between the terminal of one neuron and the dendrites of another neuron, and the place where neurotransmitters are released is called…
the synaptic cleft
changes in membrane potential that vary in size, as opposed to being all-or-none; local changes in the membrane potential
graded potential
most graded potentials are ____ meaning they raise the membrane potential, making it more positive. These are known as ** postynaptic potentials**
excitatory
____ make the membrane more negative, resulting in hyperpolarization
inhibitory postsynaptic graded potentials (IPSPs)
True or False
Graded potentials can add up together if they are located close to eac othr or happen within a very short time span
True, this is called spatial and temporal summation respectively
a specialized part of the cell body (or soma) of a neuron that connects to the axon
axon hillock
structures past the axon hillock that open and close in response to changes in the membrane potential
voltage-gated sodium channels
what must happen in the neuron (hint: include voltage gated sodium channels in your answer) for depolarization to occur?
Enough graded potentials must occur to add up to the threshold potential that causes voltage gated sodium channels to open. Then Na+ will rush into the cell, causing the membrane potential to increase, becoming more positive than the threshold. This causes other channels to open up as well, the result being a cascade of depolarization going down the axon terminal
occurs when voltage gated potassium channels open up, and sodium channels close at +35mV. K+ is rushing out of the cell, making the membrane potential negative
repolarization
when the cell potential becomes so negative that potassium channels close, and Na+/K+ ATPase is able to bring the membrane potential and concentration gradient back to normal
hyperpolarization
when depolarization hits peak at +40mV, and sodium channels cannot open for a certain period of time
absolute refractory period
this serves as a safety check that prevents the signal from traveling backwards
when sodium channels are able to open again but the membrane remains hyperpolarized
relative refractory period
it is possible - just difficult - to generate an action potential at this time
what ion controls the channels that are at the end of an axon?
Ca2+
channels open in response to the change in membrane potential caused by the arriving wave of depolarization
the opening of Ca2+ channels is reponsible for the exocytosis of ____ from vesicles?
neurotransmitters
process by which hydrolytic enzymes break neurotransmitters apart, so as to prevent further receptor binding
degradation
the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal or glial cell after it has performed its function of transmitting a neural impulse
reuptake
NT that activates muscle contraction at the neuromuscular junction. Used in all autonomc outputs fromthe brain to the autonomic basal ganglia. Used in the parasympathetic nervous system for post-ganglionic connections
acetylcholine
p. 142
NT used in reward & motor pathways. Associated with Parkinson’s and the loss of ____ neurons in the substantia nigra
dopamine
suppresses pain and can produce euphoria
endorphin
stimulates the fight or flight response
epinephrine
inhibitory NT of brainstem and spinal cord
glycine
NT used in post-ganglionic connections in the sympathetic division of the autonomic nervous system. Increases arousal, alertness, and focuses attention
norephinephrine
NT that regulates intestinal movement in the GI tract. Regulates mood, appetitie, and sleep in the brain. Low levels associated with depression and mood disorders.
serotonin
Compare and contrast the signaling methods of electrical vs chemical synapses
Chemical synapses have the NT bind to the transmembrane receptor protein, while electrical synapses feature the direct, cell-to-cell diffusion of ions via gap junctions
the speed of transmission of chemical synapses is ____ than that of an electrical synapse
slower
____ synapses allow for the amplification of signals
chemical
____ synapses use the direct, cell-to-cell diffusion of ions through gap junctions as a signaling method
electrical
____ synapses use neurotransmitter binding to transmembrane receptor proteins as a signaling method
chemical
the ability to store charge in an electrical system; how much charge is on both sides of an insulator and the thickness of that insulation
capacitance
in a cell, the insulator is the cell membrane. The higher the membrane capacitance, the more difficult it will be to change the membrane potential, slowing down conduction and making it challenging for the neuron to depolarize
the ability to resist charge in an electrical system
resistance
True or False
The cell membranes of neurons are characterized by both capacitance, as reflected by the difference in charge in both sides of the membrane, and** resistance**
True
true or false
Larger neurons are easier to depolarize
False
Larger surfaces = more area to store charge along the membranses = higher capacitance, which makes it harder to depolarize
how much the cytoplasm impedes the flow of ions
cytoplasmic resistance
the more the cytoplasm impedes the flow if ions, the slower and more difficult conduction will be
the ability of the membrane to seperate charge
membrane resistance
high membrane resistance promots the effective tranmission of an action potential
charges stored across the membrane
membrane capacitance
name the neuron structure
____ prevents the outflow of ions, significantly decreasing capacitance, allowing for conduction to be rapid down the axon
myelin
potential that. ispresent when the influx and efflux od ions through the membrane equalizes; the membrane potential that the system “balances out” at when it’s not actively depolarizing
resting membrane potential
What equation can we use to determine the cell potential of a neuron?
Nernst equation
pg. 145 biology
when an action potential reaches the end of an axon, the signal is transmitted to the ____ via a neurotransmitter
post-synaptic membrane
Calcium then rushes into the presynaptic axon terminal, which sends vesicles carrying the NT into the synaptic cleft, The NT binds to the post-synaptic membrne and serves as a catylyst for its effect
