CH2 Flashcards
contains the cell body, nucleus and other organelles; all proteins, receptors, are made here and transported to more distant targets
cell body / soma
extensions that receive information
dendrites
extension that conducts electrical signals from the cell body to the terminal boutons; may have multiple projections sites
axon
not excitable cells, but play key roles in influencing neural action and its transmission (structural support of ion concentrations, reuptake, etc.)
glial cells
main integrating/processing neurons of a brain region; axons project out of the region in which the neuron resides and/or to local neurons within the same region
projection/principle neurons
neurons with many dendritic spines
striata’s medium spiny neurons
any neuron that are in between sensory and motor neurons; cells whose axons remain within a particular brain regions that can connect to projection neurons and other inter neurons
interneurons
interneurons are typically ____ than projection neurons, are usually ______, using ____ or ____ as a NT, and regulate patterns of activities in large ______. Excitatory neurons often can connect to both inhibitory interneurons and other excitatory cells via _____
smaller, inhibitory, ACh, GABA, networks, collaterals
Initial sites of action of neurotransmitters (or drugs)
receptors
______, _____, _____ and ____ ions are needed for neuron function and must be in specific concentrations for the cell to fire
Na+, Ca2+, K+. Cl-
channels that are normally closed and open for a brief period of time in response to specific stimuli before closing
gated channels
ion channels that open when electrical potential across the membrane is altered
voltage gated ion channel
channels that open when a ligand binds to a receptor
ligand gated ion channel
special case of ligand gated channel activated by attachment of a phosphate group on the intracellular side of the receptor
second messenger
Some channels, such as the _______ receptor, are both ligand and voltage gated
NMDA glu
The resting membrane potential inside the cell is ______, driven primarily by higher concentration of positively charged ions _____, _____ and _____ outside the cell, and higher concentration of negatively charged ions _______ inside the cell
negative, Na+, K+, Ca2+, intracellular proteins
Non gated ____ channels always stay open, allowing most positvely charged K+ into the cell through ____ _____ and _____. However, voltage gated ______ channels are closed at rest. The result is a resting potential of _____, where K+ is balanced in the two factors driving it in and out of the cell
K+, electrical attraction, diffusion, Na+, -70mV
occurs when a neuron depolarizes to the threshold of -50mV
action potential
The 4 stages of an action potential
- depolarization causes voltage gated Na+ to open, and Na+ enters (+45mV), 2. action potential causes voltage gated K+ channels to open, and K+ exits the cell 3. Na and K channels both close 4. Na/K pump puts the ion distribution back in balance via active transport, to maintain resting potential
synaptic inputs that cause excitatory post synaptic potentials (EPSPs or IPSPs)
local potentials
local potentials are _____ meaning that a larger stimulus will provide a greater magnitude of hyperpolarization or depolarization. Several small local potentials can add up to larger changes in membrane potential. In contrast, action potentials are ______ (size is unrelated to stimulation) Many NTs and drugs alter neural activity by modulating the impact of inhibitory/excitatory inputs or changing cell _____. Local potentials are generated on the dendrites and _____. They ____ rapidly as they travel along the cell membrane
graded, all-or-none, excitability, cell body, decay
the system that controls voluntary muscles, delivers sensory input to the brain
somatic system
regulates the internal environment by innervating smooth muscles (intestine, bladder) cardiac muscles, and glands (adrenal, salivary etc.)
autonomic system
fight or flight system that dominates during times of stress, excitement and exertion; increases heart rate, blood pressure, blood flow, adrenaline secretion
sympathetic division
dominated when energy reserves can be conserved; increases salivation, digestion, storage of glucose, nutrients, slows heart rate, decreases respiration
parasympathetic division
Many psychoactive drugs affect ___and ____ which are used by ANS neurons, and cause numerous side effects
ACh, NE
The spinal cord sends ___ inputs to the sympathetic ganglia and _____ ____, typically being ______ and act on ____ receptors. Sympathetic ganglia then send ____ inputs to the organs , and this is also secreted into the blood from the _____ gland. NE can be excitatory or inhibitory depending on the receptor ______.
ACh, adrenal glands, excitatory, nicotinic, NE, adrenal, subtype
Drugs that increase NE activity typically _______ sympathetic activation. Drugs that increase ____ release or stimulate nicotinic receptors (ionotropic) , can _____ sympathetic functioning (ex. nicotine)
increase, ACh, increase
The spinal cord projects to parasympathetic ganglia that send short projections to the glands. They exert their effects via the _______ ACh receptors (g coupled). Parasympathetic system uses ACh exclusively
muscarinic
Muscarinic _____ reduce parasympathetic function, resembling sympathetic activation, while ____ do the opposite
antagonist, agonists
neurotransmitters are often ____ in function to maintain a balance (opposite to hormones) and ___ ___ quickly
localized, broken down
convert physical stimuli in the world around us and in our internal environment into an electrical signal and transmit this information to circuits of interneurons
sensory neurons
direct a biobehavioral response appropriate for the situation
motor neurons
Cells that are unspecialized and have the capacity to become any specific tissue or organ
stem cells
integration of information from many cells
convergence
transmission of information to several other cells
divergence
covers dendrites and increases the receiving surface area
dendritic spines
numerous branches/split of the axon
axon collaterals
fatty insulating coatings made by Schwann cells that increases the speed of conduction. The thicker it is the faster the conduction. It reduces the energy required to restore the neuron to resting state
myelin
breaks in the axon where there is no myelin
nodes of ranvier
exchanges every 3 ions of Na+ pumped out, with 2 K+ ions pumped in
Na+/K+ pump
bringing the membrane potential farther from threshold for firing by Cl- entry or K+ exit; more negative inside the cell
hyperpolarization
bringing membrane potential closer to threshold for firing by Na+ entry; more positive inside the cell
depolarization
+40mV when Na+ channels close and another action potential cannot occur
absolute refractory period
When the membrane potential is hyperpolarized for a short time until K+ diffuses away, or is exchanged for Na+ with a pump. Takes more excitation to reach the threshold
relative refractory period
only regeneration of action potential at the nodes of ranvier
saltatory conduction
Action potentials are only
depolarizing
local ______ such as procaine or lidocaine, block _____ channels, while ____ drugs reduce Na+ conduction by blocking closed channels to prolong the refractory state. ____ such as saxitoxin or tetrodotoxin block Na+ channels
anaesthetics, Na+, antiepileptic, neurotoxins
both sensory and motor neurons; communicates with heart, lungs, gastrointestinal tract
vagus nerve
sensory afferents carry sensory information from the surface of the body to the _______, while motor efferents carry signals from the _____ of the spinal cord to the skeletal muscles
dorsal horn, ventral horn
tissue below the bony covering of the skull that provides additional protection
meninges
outermost, toughest layer
dura mater
membrane with a weblike sublayer filled with CSF
arachnoid
thin layer of tissue that sits directly on nervous tissue
pia mater
irregularly shaped cavities in the brain
cerebral ventricles
channel that runs the length of the spinal cord
central canal
bathes the exterior of the brain and spinal cord and involved in exchange of nutrients and waste products between brain and blood
Cerebrospinal fluid
cell bodies
grey matter
myelinated axons
white matter
regulates heartrate, digestion, respiration, blood pressure, coughing, vomiting
medulla
a sensorimotor center responsible for body position, balance, corrective movements, etc.
cerebellum
important for arousal, attention, sleep and muscle tone
reticular formation
principle source of all neurons that release NE, arousal, vigilance, attention
locus coeruleus
surrounds aqueduct that connects third and fourth ventricles; modulation of pain (many opioid receptors), specific specific reactions
periaqueductal grey
innervate the striatum, use DA, initiation and modulation of movement
substantia nigra
has projections to NAcc, amygdala, PFC, etc
ventral tegmental area
Process and distribute sensory and motor information to cerebral cortex
thalamus
integrates emotional responses and regulating motivated behavior and learning
limbic system
deep grooves in the cerebral cortex
fissures
deep grooves in the cerebral cortex
fissures
smaller grooves in the cortex
sulci
bulges of tissue
gyri
____ arrangement of cell in the cortex provide functional units for integration of information between various cortical regions
vertical
small primary area, adjacent secondary cortex, tertiary areas, in each lobe
association cortex
conscious awareness of sensory experiences, initial cortical processing
primary cortex
analyzes information from primary area; recognition / perception of stimulus, memories are stored
secondary cortex
higher order perceptual functions; integration of multiple characteristics of an event
tertiary cortex
important for decision-making, planning actions, evaluating optimal strategies
prefrontal cortex
rat brains have similar ____, _____ and ____ to humans, but less proportion of _____. The cortex is ____ and the _____ and ____ are larger
nuclei, fiber tracts, types of cells, PFC, smooth, olfactory bulb, midbrains
the parts of the myelencephalon
medulla, corticospinal neurons
parts of the metencephalon
pons, cerebellum, reticular formation (LoCe, dorsal.median raphe nuclei)
parts of the mesencephalon
tectum (superior and inferior colliculi), tegmentum (PaqGrey, SubsN, VTA)
basal ganglia consist of the
caudate, putamen, substantia nigra, globus pallidus
