neuro 2026 lil study guide exam 1

in the spinal cord, what root carries sensory into brain?

dorsal root

in the spinal cord, what root carries motor commands from brain?

ventral root

in the cerebellum, what are peduncles?

bundle of nerve fibers (like major communication highways)

in the cerebellum the superior peduncle connects what to what?

the cerebellum to the midbrain

in the cerebellum, the middle peduncle connects what to what?

cerebellum to pons

in the cerebellum, the inferior peduncle connects what to what?

cerebellum to medulla

for the superior, middle, and inferior peduncles what is the order in which they connect? pneumonic

“my poor mom” midbrain, pons, medulla (connected to cerebellum)

the superior peduncle carries in or out of the cerebellum?

out

the middle peduncle carries in or out of the cerebellum?

into

the inferior peduncle carries in or out of the cerebellum?

in

in the brain, gray matter is located where?

outside the brain (cortex)

in the brain, white matter is located where?

inside the brain

in the spinal cord, gray matter is located where?

inside the spinal cord

in the spinal cord, white matter is located where?

outside of the spinal cord

in the cns, the collection of cell bodies is called what?

nuclei

in the pns, the collection of cell bodies is called what?

ganglia

afferent = ?

carries sensory towards the cns

efferent = ?

carries motor away for the cns

oligodendrocytes are responsible for?

myelinating neurons in the cns

schwan cells are responsible for what?

myelinating neurons in pns

astrocytes are responsible for?

signaling, cleaning, + nourishing

microglial cells are responsible for what?

defending

depolarization in the cell means it becomes more positive or negative?

more positive + more likely to fire

hyperpolarization in the cell means it becomes more positive or negative?

more negative + less likely to fire

being “hyper” is a bad thing so hyperpolarization is when the cell becomes more?

negative bc being hyper is a bad this

voltage gated channels are propagated by what?

action potentials

modality gated channels are propagated by what?

local potentials

spatial summation is signals from where?

different locations to one

temporal summation is when

signals rapidly repeat over time

convergence is

many neurons to one

divergence is

one neuron to multiple neurons

what happens when an AP arrives?

1. ap arrives

2. voltage gated channels open

3. ca enters

4. synaptic vessels release nt

5. synapse

6. nt crosses

7. nt binds to receptor

8. ion channels open

presynaptic facilitations means what?

more neurotransmitter released

inhibition means?

decreases the signal → releases less neurotransmitter

main characteristics of neurotransmitters are…

fast, short lasting, more local and often changes membrane potential

they transmit a signal

main characteristics of neuromodulators are…

slow, often long-lasting + modifies how a cell responds

true or false; the same chemical can be either a NT or NM depending on where its released?

true

ligand- gated channels are triggered by what?

NT’s

g-protein activation are…

slower, longer lasting and indirect (includes 2nd messenger)

general function of acetylcholine ?

mm contraction

general function of glutamate?

major excitatory NT in CNS, learning + memory

general function of glycine?

major inhibitory NT in CNS, reduces neuronal activity especially in brainstem and spinal cord

general function of GABA?

major inhibitory NT in CNS, especially in brain

general function of dopamine?

mvmt, motivation, reward, attention + learning

general function of norepinephrine?

alertness, attention, stress + regulates sympathetic activity

general function of serotonin?

mood + sleep

general function of histamine?

wakefulness, immune + inflammatory responses

general function of substance p?

pain transmission

general function of opioid peptide?

reduces pain

general function of calcitonin gene-related peptide (cgrp)?

pain transmission/modulation + vasodilation

where does the dcml decusate?

in the medulla

where does the lstt tract decusate?

in the spinal cord

where does the touch on face tract decusate?

brainstem (mid pons)

where does the pain/temp on face tract decusate?

cervical region of spinal cord

where do the anterior medial spinothalamic tracts decusate?

(spinomesencephalic, spinoreticular, and spinolimbic (emotional))

all 3 in spinal cord

where does the spinomesencephalic tract terminate?

in the midbrain

where does the spinoreticular tract terminate?

in the reticular formation of the brain

where does the spinolimbic (spinoemotional) tract terminate?

in the emotional areas of the cerebral cortex

what is the function of the spinomesencephalic tract?

turn eyes towards stimulus (nociceptive info)

what is the function of the spinoreticular tract?

sleep/ wake, arousal, and attention

what is the function of the spinolimbic tract?

transmits slow, dull, aching pain and attaches emotion

ex. angry when you stub ur toe

what are the 2 conscious relay pathways?

dcml and lstt

what are the 3 divergent pathways?

spinomesencephalic, spinoreticular, and spinolimbic

what is the non-conscious pathway?

spinocerebellar tract

what is the function of the spinocerebellar tract?

proprioception info for automatic adjustments to posture and mvmt to cerebellum

this tract corrects when you trip

what are the 4 spinocerebellar tracts?

1. posterior spinocerebellar

2. cuneocerebellar

3. anterior spinocerebellar

4. rostrospinocerebelllar

what spinocerebellar tract is responsible for somatotopically arranged info from the legs/lower half of the body?

posterior spinocerebellar

what spinocerebellar tract is responsible for somatotopically arranged info from the arms/ upper half of the body?

cuneocerebellar

what spinocerebellar tract is responsible for the internal feedback from the thoracolumbar region?

anterior spinocerebellar

what spinocerebellar tract is responsible for the internal feedback from the cervical region?

rostrospinocerebellar tract

tonic receptors respond…

the entire time the stimulus is present

phasic receptors…

adapt to a constant stimulus and stop responding

some examples of tonic receptors are…

pain and mm length (stretching)

responds the entire time

some examples of phasic receptors are…

putting a watch on

you feel it initially but they stop responding eventually bc it is non-threatening

comes in phases

higher receptive field density (alot packed into one area) =

small receptive fields (fingertips)

low receptive field density (not many in one area)=

large receptor fields (skin on back)