Mind brain and behavior EXAM 1

signaling, somatosensory, neuroanatomy, and motor systems

Dendrite

A?

Axon hillock

B?

axon hillock

part of neuron where action potentials are initiated, integrates signals received from the dendrites before transmitting down axon

graded potentials (IPSP and EPSP)

excitatory (depolarizing, making the cell more positive) or inhibitory (hyperpolarizing, making the cell more negative), Influence whether an action potential will be triggered by summing together

node of ranvier

C?

Axon terminal

D?

schwann cell

E?

myelin sheath

F?

nucleas (within soma) 

G? 

3 Na out, 2 K in

how does the Na-K pump maintain a neurons resting membrane potential

action potential

ALL or NONE depolarization and repolarization of neuronal membrane that carries an electrical signal along the axon

potential sum (EPSP>IPSP) reaches threshold

how is an action potential generated? 

Ca, K, and Na

Important electrolytes involved in action potential generation and transmission

during depolarization, initiates action potential 

when is there an INFLUX (entry) of Na during AP generation

after the peak, returns to resting potential

when is the an EFFLUX (exit) of K during AP generation

Synapse

interface/structure permitting a neuron to pass a chemical or electrical signal from one neuron to the next

synaptic cleft (chemical)

MOST COMMON SYNAPSE, small gap between the presynaptic and postsynaptic neurons where neurotransmitters are released and received

gap juction (electrical)

a specialized connection that allows direct electrical communication between cells, facilitating rapid signal transmission

Ca

electrolytle required for stored neurotransmitters to be RELEASED from AXON TERMINAL into a synapse

presynaptic axon terminal

where are neurotransmittors released from?

frequency (number of APs) 

What property of an action potential CHANGES in response to stimulus? (ie. amplitude or frequency? ) 

increases frequency

How would a high-intensity stimulus impact an action potential?

Refractory period

What property of voltage-gated ion channels allows for the unidirectional transmission of an electrical impulse down an axon?

EPSP (excitatory post-synaptic potential)

promotes neuron firing,  causes depolarization of the postsynaptic membrane by allowing positively charged ions (such as Na⁺ and Ca²⁺) to enter the cell

IPSP (inhibitory post-synaptic potential)

inhibit neuron firing, causes hyperpolarization of the postsynaptic membrane by allowing either positive ions (K⁺) to leave or negative ions (Cl⁻) to enter the cell

myelinatiom

significantly INCREASES speed of signal transmission down an axon by insulating the axon membrane and enabling a process called saltatory conduction

Nodes of Ranvier

gaps in the myelin sheath that facilitate rapid signal conduction along the axon by allowing ions to flow in and out of the neuron.

Saltatory conduction

action potentials jumping between the gaps (Nodes of Ranvier) in myelinated axons, INCREASES speed of signal transmission along the neuron.

Dopamine

neurotransmitter for MOVEMENT and REWARD

Glutamate

Main EXCITATORY neurotransmitter in the brain

Serotonin

neurotransmitter for MOOD

Acetylcholine

neurotransmittor in NEUROMUSCULAR junction and Autonomic nervous system, particularly parasympathetic

GABA

Main INHIBITORY neurotransmitter in the brain

Norepinephrine

neurotransmitter for AROUSAL and ALERTNESS, Sympathetic nervous system

Melatonin

neurotransmitter for CIRCADIAN RHYTHM

Oxytocin

neurrotransmitter involved in Childbirth, Breastfeeding, and Bonding

Absolute refractory period

Na+ channels are inactivated, subsequent AP is NOT possible 

Relative refractory period

residual Na+ channel inactivation makes it harder to generate AP, but possible

thalamus 

part of the brain that serves as a relay station for sensory and motor signals to the cerebral cortex.

corpus callosum

a band of nerve fibers that CONNECTS the LEFT AND RIGHT cerebral hemispheres, facilitating interhemispheric communication.

central sulcus

a prominent groove that SEPARATES FRONTAL lobe from PARIETAL lobe

1st order neuron (SENSORY tract)

FIRST SENSORY NEURON to get the SIGNAL that something happened

2nd order neuron

SENSORY neuron that goes up to the THALAMUS

3rd order neuron

SENSORY neuron that goes from THALAMUS TO CORTEX

upper motor neuron

cells in the CNS where MOTOR impulse ORIGINATES

lower motor neuron

cells in the PNS synapsing on the MUSCLE itself

decussation

the crossing of nerve fibers from one side (ipsilateral) of the brain or spinal cord to the other (contralateral)

ipsilateral

referring to the SAME SIDE of the body as another structure or location

contralateral

referring to the OPPOSITE SIDE of the body compared to another structure or location

acetylcholine 

neurotransmitter primarily used in the PARASYMPATHETIC nervous system (rest and digest) 

norepinephrine

neurotransmitter primarily used in the SYMAPATHETIC nervous system (fight or flight)

nucleus/ganglion

clusters of neuronal soma (cell bodies) in the peripheral nervous system (PNS) and central nervous system (CNS)

Adult nerve cells do not divide

why is recovery for a nervous system injury/trauma often difficult or incomplete?

neural plasticity

capacity of the nervous system to change and adapt in response to experience, learning, or injury

long term potentiation (LTP)

patterns of recent synaptic activity that produce lasting INCREASE in signal transmission (SYNAPTIC STRENGTH)

synaptogenesis

the process of forming new synapses between neurons, critical for neural development and plasticity

long term potentiation (LTP)

major mechanism of learning and memory by strengthening the connections between neurons

increased excitatory post-synaptic receptor density 

What is the result of long term potentiation (LTP)?

long term potentiation (LTP) and synaptogenesis

What are 2 main cellular mechanisms underlying neural plasticity?

increased post-synaptic receptor density (# of receptors) 

How does long-term potentiation (LTP) increase synaptic efficacy (effectiveness)?

use-dependent plasticity/ motor learning

A professional violinist has increased grey matter density in the sensorimotor cortex controlling their left hand.  This is an example of _________.

motor learning

increases the number of synapses in motor cortex through practice and experience

gray matter

matter composed primarily of neuronal cell bodies; it plays a key role in processing and transmitting information.

white matter

matter with axons with glial sheath (myelin) that facilitate communication between different brain regions.

transmitter release

proportional to the FREQUENCY of action potentials

A-delta (type III) 

nerve fibers that sense FAST, SHARP PAIN and COLD 

C-fiber (type IV)

nerve fibers that sense SLOW, DULL PAN, and WARM

mechanoreceptors

specialized structures at terminals of sensory nerves that detect stimuli such as touch, pressure, and vibration.

merkels disks

superficial nonencapsulated mechanoreceptors

meissner corpuscle 

superficial ENCAPSULATED mechanoreceptors in fingertips, palm, feet and lips

ruffini endings 

deep mechanoreceptos in skin and joint ligaments 

pacinian corpuscules

subcutaneous nechanoreceptors in connective tissue of skin, periosteum, and joint capsule

meissner and pacician corpuscles (rapidly adapting) 

mechanoreceptors with QUICK response, detect MOTION and VIBRATION

merkels disks and ruffini endings (slowly adapting)

mechanoreceptors with SUSTAINED response, detect STEADY presence and INTENCITY of stimulus

merkel disk

mechanoreceptor that senses object FORM and TEXTURE

meissner corpuscle

mechanoreceptor that senses OBJECT MOTION

ruffini ending 

mechanoreceptor that senses joint conformation, posture, and stereognosis

pacinian corpuscle

mechanoreceptor that senses OBJECT VIBRATION

fingertips

which body part has the highest TACTILE SENSITIVITY

proprioception 

the body's ability to SENSE position, movement, and equilibrium through sensory feedback from MUSCLES, TENDONS and JOINTS

periodontal ligament receptors 

after tooth extraction or tooth loss, information on the load exerted on a tooth is no longer available due to the abscnce of which receptor? 

nociceptor

a type of sensory receptor responsible for detecting PAIN or harmful stimuli in the body

myelinated a-delta and unmyelinated C fibers

nerve fibers that transmit BURING PAIN caused by HIGH TEMP

motor cortex 

which structure is prrimarily involved in generating fine motor contrrol of fingers? 

false

T/F tongue or jaw tremor found in parkinsons is a dysfunction affecting the direct pathway

DCML and ALS

two main ascending SOMATOSENSORY pathways

dorsal column medial lemniscal system (DCML)

responsible for discriminitive/FINE touch, conscious proprioception, and steriogenesis (identify object by touch alone)

anterolateral system (ALS)

A major ascending somatosensory pathway responsible for transmitting PAIN, temperature, and CRUDE touch sensations to the brain.

medial lemniscus (lower medulla)

where is the decussation of the DCML pathway?

spinal cord 

where is the decussation of the ALS pathway?

spinal cord (dorsal root ganglion)

location of 1st order neuron in DCML pathway

spinal cord

location of 1st order neuron in ALS pathway

medulla

location of 2nd order neuron in DCML pathway

spinal cord

location of 2nd order neuron in ALS pathway

thalamus

location of 3rd order neuron in DCML pathway

thalamus 

location of 3rd order neuron in ALS pathway 

ipsilateral (same) (DCML has not decussated yet)

An injury at the level of the SPINAL CORD would result in LOSS of FINE TOUCH and PROPRIOCEPTION (DCML) on the _______ side as the injury

contralateral (opposite)

An injury at the level of the SPINAL CORD would result in LOSS of PAIN and TEMPERATURE sensation (ALS) on the _______ side as the injury

dental pulp and PDL

where are the sensory receptors for the teeth?

CN V (trigeminal)

Which nerve transmits oral sensation from teeth, tongue, and TMJ?