Intro to Neuro Review Flashcards
Central Nervous System
Brain and Spinal Cord; Protected inside bone (skull and spine)
Peripheral Nervous System
cranial nervous and spinal nerves; exists outside of skull and vertebral column
what is allostasis?
the process of achieving stability (homeostasis) through physiological or behavioral change; role of the visceral motor system
what are the targets of the autonomic nervous system
heart, organs, glands, smooth muscle, pupil and eyelid muscles
what is the role of the parasympathetic nervous system
rest and digest
what is the role of the sympathetic nervous system
fight or flight
describe the nerve organization of the sympathetic division of the nervous system
Short preganglionic neuron for fast activation, long lower motor neuron, Ach Ionotropic receptor between pre and post ganglion, Adrenergic (norepinephrine) receptor between motor neuron and muscle
describe the nerve organization of the parasympathetic division of the nervous system
Long preganglionic neuron, short lower motor neuron, Ach ionotropic receptor between pre and post ganglion, muscarinic (Ach) receptor between motor neuron and smooth muscle
what is the function of the blood brain barrier
protects the brain from harmful substances in the blood; keeps blood cells, proteins, toxins, hormones, and bacteria out of brain tissue
How is the blood brain barrier formed
Formed by tight junctions between capillary endothelial cells within the brain and spinal cord
how are tight junctions maintained in the blood brain barrier
astrocytes
what gets through the blood brain barrier
anything that is small and lipid soluble or has a specific transporter
what is the function of the medulla
includes neurons that maintain normal, rhythmic breathing
what is the function of the pons region
includes axons that allow the cerebellum to communicate with the brainstem and cerebral cortex
what is the function of the midbrain
localization of visual and auditory stimuli
what is the function of the cerebellum
motor planning and motor learning
what is the function of the thalamus
relays information going to and coming from the neocortex
what is the function of the hypothalamus
regulates the autonomic nervous system and hormone release, sleep/wake cycle, controls pituitary gland
what are the sulci
grooves in the brain
what are the gyri
rounded regions between sulci
what are the brain fissures
deep sulci (grooves)
what are the function of the gross structures (sulci, fissures, gyri)
processing of sensory input, initiation planning of movement, higher order functions
what are the lobes of the cerebral cortex
occipital lobe, temporal lobe, frontal lobe, parietal lobe
what is the post central gyrus
contains the primary somatosensory cortex
what is the precentral gyrus
contains the primary motor cortex
what is the function of the occipital lobe
vision
what is the function of the parietal lobe
somatosensory (touch and pain), late stage vision
what is the function of the temporal lobe
hearing, memory, language comprehension
what is the function of the frontal lobe
planning and signaling movements, working memory, inhibition of inappropriate behavior, planning
what is the function of the limbic system
assigns emotional value to sensory information, sexual behavior, reward and punishment centers, site where drugs produce euphoria
what is the function of the hippocampus
involved in memory consolidation and provide the organisms context
what is the function of the amygdala
matches emotions with the action of the autonomic nervous system
what are the structures in the basal ganglia
striatum (caudate/putamen), globus pallidus, substantia nigra
what is the function of the basal ganglia
control voluntary smooth movement
how do stimulants affect the basal ganglia
increases motor activity
what is the primary reward synapse in the brain
ventral tegmental area releases dopamine to the nucleus acumens
what is the feeling of euphoria caused by
dopamine release from VTA to the nucleus acumbens
what is the function of the Na-K ATPase
uses ATP to move sodium and potassium against their concentration gradient
how many Na ions are transported for every K ion in the Na-K ATPase
3 Na ions for every 2 K ions
what does it mean that the Na-K pump is electrogenic
it causes a net transfer of one positive ion which ultimately affects the resting membrane potential
what are the six features of an action potential
threshold, upstroke, downstroke, afterhyperpolarization, absolute refractory, relative refractory
at what point does an action potential become all or nothing
when it reaches threshold (-55 mV)
what is the absolute refractory period
time after an action potential when sodium channels are inactivated and another action potential can not occur
what is the relative refractory period
time after an action potential when some sodium channels have recovered but K efflux is still active; requires a strong stimulus to evoke another action potential
what is the function of the absolute refractory period
ensures one way propagation of signals
what is the function of the relative refractory period
ensures the rate of firing is proportional to the intensity of the stimulus
what cells cause myelination in the peripheral nervous system
schwann cells
what cells are responsible for myelination in the central nervous system
oligodendrocytes
compare oligodendrocytes to schwann cells
one oligodendrocytes myelinates multiple axons in the CNS whereas one schwann cell myelinates one axon in the PNS
what is the function of myelin
acts as an insulator to speed up propagation of action potentials; prevenets ion leakage
what are the criteria for neurotransmitters
- NT is synthesized and stored in presynaptic neuron
- released in response to an action potential
- has post synaptic receptors
- has mechanism for synaptic cleft removal
what triggers vesicle fusion to the membrane
calcium
what is the function of synaptotagmin
senses calcium then binds to the SNARE complex to trigger release of vesicles
what is an ionotropic receptor
ligand gated ion channel, NT binding directly opens/closes channel, fast
what is a metabotropic receptor
G-protein coupled receptor, NT binding indirectly affects ion channel, slow
what is spatial summation
multiple inputs firing in different locations at the same time
what is a blue trace in spatial summation
one input firing alone causes a small depolarization but not enough to reach AP threshole
what is a brown trace in spatial summation
multiple inputs fire simultaneously and their combined affects cause an action potential
what is temporal summation
a single input fires at high frequency
what is a blue trace in temporal summation
two firings with a pause in between does not cause an action potential
what is a brown trace in temporal summation
three firings from the same input that occur in rapid succession cause the neuron to reach AP threshold
how are NT removed from the synaptic cleft to terminate action
broken down by enzymes, transporters on neurons or glial cells
