psyc367- neuroscience: test 1

human neuroscience 🧠

cutaneous mechanoreceptors

receptors in the skin that open ion channels in response to physical distortion (stimuli)

nociceptors

receptors on the skin that respond specifically to noxious or harmful stimuli

agonist

something that mimics the effects of a neurotransmitter

antagonist

something that blocks or reduces the effects of a neurotransmitter

dura mater

“hard mother”!!- outermost meninge layer which is the thickest and strongest

pia mater

“tender mother”!!- meninge that sits tight against the brain (think seran wrap)

afferent

information that travels to the central nervous system, otherwise known as sensory information

efferent

information that travels away from the central nervous system, otherwise known as motor information

voltage-gated ion channels are located primarily at which part of the neuron

the axon hillock

which of the following is not a way that neurotransmitters are cleaned up from the synapse

1. they are inactivated or degraded by enyzmes

2. they float away

3. they are recycled by the presynaptic cell

4. they are absorbed by the postsynaptic cell

they are absorbed by the postsynaptic cell.

what creates the necessary environment for neuronal communication

electrochemical gradient

which cell is not found in the central nervous system

1. neurons

2. astrocytes

3. microglia

4. schwann cells

schwann cells

what are parts of the brain that are dense with axons

white matter

what is the period of time during which it is impossible for another action potential to fire

absolute refractory period

if you were sitting in your chair and fidgeting with your pen, which tract would be sending the info. from the CNS to your muscles

dorsolateral corticospinal tract

what brain region contributes to pain perception through initial emotion identification

insula

what ion is responsible for neurotransmitter release from vesicles

calcium

which cell is responsible for maintaining the physical structure of the brain/creating the blood brain barrier

astrocytes

what part of the brain is the central “relay station”

thalamus

what brain region is responsible for the storage of sensory information

secondary somatosensory cortex

dendrites

“tree”- recieve information

soma/cell body

contains organelles and nucleus

axon

sends information

axon hillock

gatekeeper of information

axon terminal

end of the axon, contains vesicles w/ neurotransmitters

myelin

increases speed of signal/protects the axon

nodes of ranvier

recharge/refuel stations for signal

synapse

gap between the axon terminal and the dendrites of the next neuron

step 1 of action potential

stimulus: ligand-gated ion channels open (Na+ flows in) 

step 2 of action potential

huge depolarization: voltage-gated ion channels open (Na+ flows in)

step 3 of action potential

repolarization: voltage-gated K+ channels open (slowly), flow out

step 4 of action potential

hyperpolarization: undershoot of negative charge (more negative than at rest) due to slow K+ channels

last step of action potential

return to rest: -70mV – Na+/K+ pump (3 Na+ out, 2 K+ in)

what are the 3 main divisions of the brain

brainstem, cerebrum, and cerebellum

what are the subdivisions under the brainstem

medulla, pons, and midbrain

what are the subdivisions of the cerebrum (the cortex)

frontal, temporal, occipital, & parietal lobe

function of the frontal cortex

action lob

function of the temporal lobe

hearing/processing

function of the occipital lobe

vision

function of the parietal lobe

somatosensory

function of the cerebellum

fine tuner, especially for movement

characteristics of small molecule

stored/made at the axon terminals

1 type per cell

small vesicles

fast release

ex. amino acids, monoamines

characteristics of a peptide

stored/made in the soma

multiple types per cell

dense core vesicles

slower(er) release

ex. substance P, neuropeptide Y, dynorphin

what would happen: the ion channels on the cutaneous mechanoreceptors do not function

not going to get sensation at all (not even making it to the spine!)

what would happen: the dorsal column is severed

no signal will make it to the brain (end in the spine) – no perception. reflexes still intact

what would happen: the connection between the VPN and the S1 is damaged

no perception of touch but yes reflexes

what would happen: the PPC is nonfunctional

perception–semi-intact. inhibited understanding of orientation and movement 

Ramon y Cajal

first neuroscientists, discovered the neuron

relative refractory period

a new impulse can be generated, but only by a stronger-than-normal (suprathreshold) stimulus

absolute refractory period

interval immediately following an action potential during which a second action potential cannot be initiated, regardless of the stimulus intensity

ligand-gated voltage channels

open when a specific chemical attaches. located @ dendrites

voltage gated ion channels

open in response to a specific charge. located @ axon hillock

excitatory post synaptic potential (EPSP)

depolarization of the next neuron- caused by Na+

inhibitory post synaptic potential (IPSP)

hyperpolarization of the next neuron- caused by Cl- or K+

propogration

progression of the action potential down the axon

electroencephalogram (EEG)

nonivasive method to record electrical activity in the brain

pros of EEG’s

non-ivasive

multipurpose

relatively cheap

cons of EEG’s

many obstructions (hair, layers, etc.)

not comfortable

depth of reading- only records outside of the brain

accuracy isn’t 100%

layers of the brain

bone- skull & vertebrae column

duramater

meninges

arachnoid layer

subarachnoid lymphatic like membrane

pia mater

brain

cerebral spinal fluid

flow around arachnoid layer and SLLYM

function: makes brain float, delivers nutrients, and removes waste

central sulcus

seperates frontal and parietal lobes

lateral fissure

separates temporal from frontal and occipital lobes

longitudinal fissure

separates hemispheres

gray matter

areas of brain dens with cell bodies and dendrites

white matter

communication highways- areas of brain dense with axons

outermost layer

higher order thinking

subcortical layer

basic level cognition

commissure

white matter connecting left/right hemispheres

functional MRI (fMRI)

detects changes in blood/oxygen levels as an indirect measure of activity

helps in finding functional connectivity

structural MRI

anatomic information

fMRI pros

noninvasive

functional- where is energy being used/required

3d image

subcortical images

fMRI cons

EXPENSIVE

must hold fully still

blood/oxygen level is an indirect measure- room for error

what neurotransmitters can not excite AND inhibit

glutamate- only excitatory

GABA- only inhibitory

glycine- only inhibitory

ionotrophic receptors

neurotransmitter attaches to receptors @ active sight to open ion channel

receptor and ion channel are 1

excitatory OR inhibitory

1:1 NT to open ion channel

metabotrophic receptor

neurotransmitter attaches to receptor @ active sight to activate a G-protein

receptor and ion channel are not the same

excitatory or inhibitory

1 NT has multiple effects

sensation

detection of stimuli by specialized receptors

afferent

info going AT the CNS- sensory!!

efferent

info that exits the CNS- motor!!

what is process of sensation

stimulus

cutaneous mechanoreceptor

through dorsal root of spinal nerve

SPLIT in dorsal horn- main axon goes into dorsal column (reflex)

second axon goes up dorsal column

1ST ORDER NEURON- @ medulla- info crosses into opposite side (contralateral)

2ND ORDER NEURON- @ thalamus- organized in ventral posterior nucleus

when does perception begin

3RD ORDER NEURON- @ primary somatosensory cortex (s1)

primary somatosensory cortex (s1)

initial identification of sensory information

secondary somatosensory cortex (s2)

storage, processing, & retention of sensory info- remembering what feels like what!

posterior parietal cortex (PPC)

gives orientation and movement information- such as grabbing water in the dark