PSB2000 State-Mandated Neuro Quiz - Nelu Radpour

What are the four functional zones of a neuron?

Input (dendrites), Integration (soma), Conduction (axon), Output (axon terminals)

Where does information enter a neuron?

Dendrites

What is the function of the soma (cell body)?

Integrates incoming signals and determines whether to fire

Where is the action potential initiated?

Axon hillock (trigger zone)

What is the function of the axon?

Conducts the action potential

What is found in axon terminals?

Vesicles containing neurotransmitters

What is myelin?

Fatty insulation around axons that increases signal speed

What cells produce myelin in the CNS?

Oligodendrocytes

What cells produce myelin in the PNS?

Schwann cells

What is saltatory conduction?

Action potentials 'jump' between nodes of Ranvier

What is an action potential?

A rapid electrical signal that travels down the axon

Where does an action potential begin and end?

Begins at axon hillock, ends at axon terminals

What happens during depolarization?

Sodium (Na⁺) enters the neuron

What happens during repolarization?

Potassium (K⁺) leaves the neuron

What is hyperpolarization?

Membrane becomes more negative than resting potential

What is the refractory period?

Time when neuron cannot fire another action potential

Where are action potentials regenerated in myelinated axons?

Nodes of Ranvier

What increases conduction velocity?

More myelin and larger axon diameter

What is a synapse?

The junction between two neurons

What are vesicles?

Structures that store neurotransmitters

What happens when an action potential reaches the terminal?

Neurotransmitters are released into the synapse

What do neurotransmitters bind to?

Receptors on the postsynaptic neuron

What is an EPSP?

Excitatory postsynaptic potential (increases likelihood of firing)

What is an IPSP?

Inhibitory postsynaptic potential (decreases likelihood of firing)

What determines whether a neuron fires?

Sum of EPSPs and IPSPs at the soma

What are the four lobes of the brain?

Frontal, Parietal, Temporal, Occipital

What does the frontal lobe control?

Movement, decision-making, planning

What does the parietal lobe control?

Touch and body sensations

What does the temporal lobe control?

Hearing and language

What does the occipital lobe control?

Vision

What does the longitudinal fissure separate?

Left and right hemispheres

What does the central sulcus separate?

Frontal and parietal lobes

What does the lateral fissure separate?

Temporal lobe from frontal/parietal lobes

Where is the primary motor cortex?

Frontal lobe

Where is the somatosensory cortex?

Parietal lobe

Where is the visual cortex?

Occipital lobe

What is contralateral control?

Each hemisphere controls the opposite side of the body

Where is the prefrontal cortex located?

Front of the frontal lobe

What does the prefrontal cortex do?

Decision-making, personality, impulse control

What is the ventral stream?

"What" pathway (object identification, temporal lobe)

What is the dorsal stream?

"Where" pathway (location/movement, parietal lobe)

Where is Broca's area and what does it do?

Frontal lobe, speech production

Where is Wernicke's area and what does it do?

Temporal lobe, language comprehension

What does the medulla control?

Breathing and heart rate

What does the pons control?

Sleep and relay functions

What does the midbrain control?

Movement and reflexes

What does the cerebellum do?

Coordination and balance

What does the thalamus do?

Relays sensory information to cortex

What does the hypothalamus do?

Homeostasis and hormone control

What does the hippocampus do?

Memory formation

What does the amygdala do?

Emotion (fear)

What does the corpus callosum do?

Connects the two hemispheres

What does the pituitary gland do?

Releases hormones (master gland)

What does the pineal gland do?

Regulates sleep via melatonin

What is the function of the limbic system?

Emotion, memory, motivation

What are the two main divisions of the nervous system?

CNS and PNS

What does the CNS include?

Brain and spinal cord

What does the PNS include?

All nerves outside CNS

What does the somatic nervous system do?

Voluntary movement

What does the sympathetic nervous system do?

Fight or flight

What does the parasympathetic nervous system do?

Rest and digest

What does the HPA axis release?

Cortisol

What kind of stress response is the HPA axis?

Slow, long-term

What does the SAM axis release?

Adrenaline and noradrenaline

What kind of stress response is the SAM axis?

Fast, immediate

What brain area is first affected in Alzheimer's disease?

Hippocampus

What neurotransmitter/system is affected in Parkinson's disease?

Dopamine (substantia nigra)

What is the typical resting membrane potential of a neuron?

About -70 mV

What is happening inside a neuron at resting potential?

Inside is more negative than outside; neuron is polarized and not firing

What voltage threshold must be reached to trigger an action potential?

About -55 mV (threshold potential)

What happens if a neuron reaches -55 mV?

An action potential is triggered (all-or-none response)

What happens to membrane voltage during depolarization?

It becomes more positive (rises from -70 mV toward +30 mV)

What ion causes depolarization?

Sodium (Na⁺) enters the neuron

What is the peak voltage of an action potential?

About +30 mV

What happens during repolarization?

Membrane voltage returns toward negative values (back toward -70 mV)

What ion causes repolarization?

Potassium (K⁺) leaves the neuron

What is hyperpolarization?

Membrane becomes more negative than resting potential

What voltage is typical during hyperpolarization?

Around -80 mV (can vary)

What is happening during the absolute refractory period?

Neuron cannot fire another action potential no matter what

Why does the refractory period matter?

It ensures signals move in one direction down the axon

What is the order of action potential phases with voltage changes?

Resting (-70 mV) → Threshold (-55 mV) → Depolarization (~+30 mV) → Repolarization → Hyperpolarization (~-80 mV) → Resting (-70 mV)