Neuroscience: Brain Structure, Neurons, and Imaging (Flashcards)

A comprehensive set of Q&A flashcards covering electrochemical transmission, neuron structure, brain regions, imaging techniques, and hemispheric specialization based on the lecture notes.

What is electrochemical transmission in the nervous system?

A system of electrical signals that trigger the release of chemicals to communicate with other cells.

What do afferent (sensory) nerves do?

Carry information to the brain through the spinal cord about the external environment and internal conditions.

What do efferent (motor) nerves do?

Carry information from the brain and spinal cord to muscles, glands, etc.

What are the main divisions of the nervous system?

Central Nervous System (CNS): brain and spinal cord; Peripheral Nervous System (PNS): connects CNS to the rest of the body.

What are neurons?

Nerve cells that handle information processing.

What are mirror neurons?

Nerve cells activated when performing an action and when observing the action; respond to both seeing and doing and have implications for social cognition.

What are glial cells (glia) and their role?

Support, nourish, and keep neurons running smoothly; not specialized like neurons; outnumber neurons 10:1; described as the pit crew of the nervous system.

What is contained in the neuron cell body?

The nucleus.

What is the function of dendrites?

Receive information and orient it toward the cell body.

What is the function of the axon?

Carries information away from the cell body toward other cells.

What is the role of the myelin sheath?

A layer of fat cells that encases and insulates most neurons, speeding up nerve impulse transmission.

What is resting potential?

The neuron is at rest with a negative charge; ion channels are closed and the cell is polarized.

Which ions are positively charged and which are negatively charged in neurons?

Sodium and potassium are positively charged; chlorine and other ions are negatively charged.

What initiates an action potential?

A stimulus raises the neuron's voltage, causing sodium channels to open and positive ions to flow in.

What happens during depolarization?

Sodium ions flow into the neuron, making it more positive (depolarized).

What happens during repolarization?

Potassium ions leave the neuron, returning it to its resting (negative) state.

What is the all-or-nothing principle in action potentials?

Once the threshold (-55 mV) is reached, the neuron fires at full strength; the impulse travels the entire axon; signal intensity is encoded by firing frequency, not size.

What is synaptic transmission?

Chemical transmission across the synaptic gap via neurotransmitters stored in vesicles in the terminal buttons.

What is a synapse?

The tiny gap between neurons across which neurotransmitters cross.

What are neurotransmitters and receptor sites?

Neurotransmitters are chemical messengers that fit into receptor sites on receiving neurons to transmit signals.

What is reuptake?

Reabsorption of unused neurotransmitters by the sending neuron when they are not received.

What is the cerebellum primarily responsible for?

Motor coordination.

What is the amygdala associated with?

Emotions.

What is brain lesioning?

Abnormal disruption to brain tissue due to injury or disease.

What does EEG stand for and what does it measure?

Electroencephalograph; measures the brain's electrical activity.

What does CAT stand for in brain imaging?

Computerized Axial Tomography.

What does PET stand for in brain imaging?

Positron Emission Tomography.

What does MRI stand for?

Magnetic Resonance Imaging.

What does fMRI stand for?

Functional Magnetic Resonance Imaging.

What is TMS and what is it used for?

Transcranial Magnetic Stimulation; used to stimulate specific brain regions.

What are the four lobes of the cerebral cortex and their primary functions?

Occipital: vision; Temporal: hearing, language processing, memory; Frontal: intelligence, personality, voluntary muscles; Parietal: spatial location, attention, motor control.

Which hemisphere is typically associated with language production and processing?

Left hemisphere (Broca's and Wernicke's areas are typically on the left).

What are Broca's area and Wernicke's area responsible for?

Broca's area: speech production; Wernicke's area: language comprehension (words, numbers, syntax, grammar).

What functions are associated with the right hemisphere?

Nonverbal processing, spatial perception, visual recognition, emotion, and face processing (fusiform face area).

What is the corpus callosum?

A bundle of axons that relays information between the two hemispheres.

What is the basal ganglia's role?

Coordination of voluntary movements.

What is the hypothalamus responsible for?

Regulating eating, drinking, sexual behavior; internal state, emotion, stress, and reward.

What is the limbic system responsible for?

Memory and emotion; discrimination of objects needed for survival and emotional awareness and expression.

What is the thalamus' role?

Relay station for much sensory information to the cortex.

What is the hippocampus' role?

Formation and recall of memories.

What is the substantia nigra and its role?

Part of the dopamine system; feeds dopamine to the striatum; input station for the basal ganglia.