BB Chapter 1

What are the primary functions of the frontal lobes?

coordinate voluntary movements, speech, memory, emotion, higher cognitive skills like planning and problem-solving, and aspects of personality.

Where are the parietal lobes located and what is their function?

The parietal lobes are located at the top of the brain, behind the frontal lobes, and they integrate sensory signals from the skin, process taste, and some types of visual information.

What is the role of the occipital lobes?

The occipital lobes process visual information, recognizing colors and shapes, and integrating them into complex visual understanding.

What is the largest part of the human brain and how is it divided?

The largest part of the human brain is the cerebrum, which is divided into two large hemispheres, left and right.

What connects the two hemispheres of the cerebrum?

The two hemispheres are connected by bundles of nerve fibers, the largest of which is called the corpus callosum.

What are the functions of the temporal lobes?

The temporal lobes are responsible for some visual processing and interpreting auditory information, as well as being associated with language, memory, and emotion.

What is the function of the hippocampus?

The hippocampus encodes new memories and is located beneath the cerebral cortex within the temporal lobes.

What role does the amygdala play in the brain?

The amygdala integrates memory and emotion.

What is the function of the cerebellum?

The cerebellum coordinates voluntary movements, helps learn new motor skills, and plays roles in spatial and temporal perception.

What might a patient with cerebellar damage experience?

A patient with cerebellar damage might have a jerky, arrhythmic gait or might be unable to accurately touch their finger to their nose.

What structures make up the basal ganglia and what is their function?

The basal ganglia, formed by various regions of the forebrain, help regulate complex body movements.

What is the limbic system and what structures does it include?

The limbic system is a collection of structures that regulate emotion and motivation, including the hippocampus, amygdala, thalamus, and hypothalamus.

What is the role of the thalamus in the brain?

The thalamus integrates sensory information and relays it to other parts of the brain.

What does the hypothalamus do?

The hypothalamus sends hormonal signals to the rest of the body through the pituitary gland.

What is the cerebral cortex and why is it important?

The cerebral cortex is a deeply folded layer of nerve tissue that increases the brain's processing power by creating space for more neurons.

How does the brain manage multitasking?

The brain manages multitasking by having distinct regions specialized for specific tasks and abilities, allowing simultaneous processing of information.

What are the basic functions of the midbrain?

The midbrain controls reflexes to sounds, inhibits unwanted body movements, and coordinates sensory input and motor output.

What is the significance of the deep folds in the cerebral cortex?

The deep folds in the cerebral cortex increase the area available for neurons, enhancing the brain's processing capabilities.

What is the relationship between the cerebellum and motor skills?

The cerebellum coordinates voluntary movements and helps the brain learn new motor skills.

What happens during the startled response to a loud noise?

The midbrain triggers reflexes that cause a startled jump in response to a loud noise.

What is the primary role of the cerebrum?

The cerebrum is responsible for higher cognitive functions, including attention, planning, and decision-making.

What is the significance of the billions of neurons in the brain?

The billions of neurons in the brain transmit information from the body and the outside world, programming responses, thoughts, emotions, and memories.

What is the function of the corpus callosum?

The corpus callosum forms a bridge between the cerebral hemispheres, allowing communication between them.

What are the primary divisions of the cerebrum used by neuroscientists to identify brain regions?

The lobes of the cerebrum.

What is the role of the midbrain in the brain's structure?

It coordinates eye movements and sits beneath the thalamus.

What functions does the hindbrain control?

Glucose regulation, sleep, and movement.

Where is the cerebellum located, and what is its significance?

It is located underneath the occipital lobe and is the second-largest part of the brain.

What is the function of the pons?

It influences breathing and posture.

What basic functions does the medulla control?

Swallowing, heart rate, and breathing.

What three parts make up the brainstem?

The midbrain, pons, and medulla.

How do neural circuits function in the brain?

They process incoming signals and produce output patterns sent to other brain regions.

What are the two types of brain waves associated with sleep, and what are their frequency ranges?

Theta waves (4 to 7 Hz) and delta waves (less than 3.5 Hz).

What is the role of the basal ganglia in movement?

They are part of a feedback loop that integrates sensory and motor signals to excite or inhibit movements.

How do neurons in the temporal lobe and parietal lobe process visual information?

Temporal lobe neurons recognize and identify objects, while parietal lobe neurons detect their spatial location.

What does the human brain's evolution from a simple tube signify?

It indicates that the brain has retained similar regions for processing information as seen in early vertebrates.

What are nerve tracts, and what are two examples?

Bundles of region-spanning neurons; examples include the corpus callosum and the anterior commissure.

What is the significance of local neural circuits in the brain?

They engage when signals arrive, turning entering signals into output patterns.

How does information move between brain regions?

Via chains of neurons that transmit signals over long distances.

What is the basic mechanism used by all brain regions to process information?

Engaging local neural circuits to analyze specialized subsets of information.

What is the relationship between neural networks and sensory input?

Neural networks provide feedback that helps integrate sensory and motor signals.

What are the characteristics of alpha and delta brain waves?

Alpha waves are of higher amplitude than beta or theta waves, while delta waves occur during deep sleep.

How do new technologies contribute to our understanding of brain function?

They allow us to observe brain regions activated during different tasks.

What does the thickness of the cortex resemble?

Shelves in a bookcase.

What is the significance of the corpus callosum?

It is the thick bundle of neurons connecting the left and right cerebral hemispheres.

What is the evolutionary significance of the human brain's structure?

It reflects the organization of specialized regions for processing information, similar to ancestral vertebrates.

What is the role of neural networks in the brain?

They integrate sensory and motor signals to facilitate complex processing.

What is a neural network in the brain?

A group of nerve tracts connecting a series of regions that route signals through the brain along a linear pathway, analyzing and organizing information.

What are the typical voltage ranges for brain wave signals detected by electrodes on the scalp?

20-200 μV for alpha and delta waves, and 5-10 μV for beta and theta waves.

How are neurons organized in the cerebral cortex?

Neurons are organized into distinct layers that span the thickness of the cortex, arranged in columns where each neuron connects with cells above and below.

What is the function of circuits in the cerebral cortex?

Circuits transform signals as they travel down a chain of neurons, building outputs that encode complex information.

What is a thalamocortical loop?

A two-way circuit that connects the thalamus with parts of the cortex, integrating sensory information.

What are brain waves?

Rhythmic, oscillating electrical patterns produced by neuronal signals looping through the thalamus and cortex, detectable with an electroencephalograph (EEG).

What are the four distinct types of brain waves?

Alpha waves, beta waves, theta waves, and delta waves, each recognized by their characteristic shape on an EEG.

What three distinct bulges developed in early vertebrates' nerve cords?

The forebrain, midbrain, and hindbrain.

What regions expanded in the forebrain of early vertebrates?

The olfactory bulbs for chemical detection and light-sensing regions for processing complex visual signals.

What is the role of the cerebellum in early vertebrates?

To control escape movements and orient the body in space.

How did the forebrain evolve in vertebrates?

New types of neurons expanded the forebrain, forming the cerebral hemispheres.

What initiates the process of recognizing characters and scenery when watching a movie?

Photoreceptors in the retina trigger electrical signals in response to specific wavelengths of light.

What happens to visual signals after they reach the optic nerve?

They travel through the optic tract to the thalamus, where neurons respond to shape, color, or movement before passing signals to the primary visual cortex.

What is the primary visual cortex responsible for?

Detecting edges of objects and integrating signals from each eye to create a three-dimensional perception.

What types of brain waves does an awake brain typically produce?

Alpha waves and beta waves.

Where do alpha waves originate in the brain?

Mainly in the parietal and occipital lobes when the brain is relaxed and eyes are closed.

What are the frequency ranges for alpha waves?

Between 8 and 13 Hz.

What are beta waves characterized by?

Frequencies ranging from 14 to 30 Hz, typically produced by the frontal and parietal regions during active processing.

What do spinal tracts consist of?

Chains of neurons that pass signals through the brainstem and spinal cord.

What is the significance of the cerebral hemispheres in mammals?

They represent the expanded regions of the forebrain that process complex information.

How do visual signals contribute to the perception of a movie?

They are processed by the brain to turn moving shapes into recognizable characters and scenery.

What is the role of the thalamus in sensory processing?

It integrates sensory information and relays it to the appropriate cortical areas.

What is the relationship between the cerebral cortex and neural circuits?

The cerebral cortex is packed with neural circuits that process and organize information.

How do signals travel from sensory receptors to the brain?

Signals travel upward from sensory receptors in skin and muscles to the thalamus and parts of the cortex that interpret touch and pressure.

What is the pathway for signals that induce movement from the brain?

Signals travel downward from brain regions, passing through the medulla and spinal cord before projecting to the body's muscles.

What role do neural loops play in motor signals?

Neural loops incorporate tracts from the cerebral cortex that allow environmental and emotional context to influence body movements.

How does the hippocampus interact with sensory cortex pathways?

Networks that loop the hippocampus into sensory cortex pathways help analyze whether environmental signals are familiar or part of a new situation.

What is the function of reflex loops in the nervous system?

Reflex loops elicit action before thoughts, controlled locally by information going in and out of the spinal cord or subcortical regions, without reaching the cortex.

What is the significance of columns in the cortex?

Each column in the cortex is dedicated to a specific processing task, but its output can be influenced by nearby circuits.

How do neurons behave in a circuit?

Every neuron behaves like a microprocessor, summing all signals received before sending its own, allowing for dynamic shifts in response.

What is neurotransmission?

Neurotransmission is the process by which chemical signals called neurotransmitters cross the synapse, allowing signals to impact the next neuron.

What triggers an action potential in a neuron?

An action potential is triggered when the sum of all signals at the dendrites rises to match the membrane's threshold voltage.

What happens when an action potential reaches the axon terminal?

It triggers ion channels to open, allowing calcium ions to flow in, which causes synaptic vesicles to fuse with the membrane and release neurotransmitters.

What is a synapse?

A synapse is a junction where signals are passed from one neuron to the next, consisting of the end of an axon, the dendrite of an adjacent neuron, and the synaptic cleft.

What are the two types of neurons?

Neurons are either excitatory, which push neighbors toward firing, or inhibitory, which suppress the activity of neighboring neurons.

What is the most common type of excitatory neuron in the cerebral cortex?

The most common type of excitatory neuron is the pyramidal cell, characterized by its cone-shaped cell body.

What is the structure of a pyramidal cell?

A pyramidal cell has two sets of branched dendrites: one set at the apex and another shorter set at the base, with a multi-branched axon sending signals to multiple destinations.

What is the ratio of excitatory to inhibitory neurons in the human brain?

About 80 percent of neurons are excitatory, while 20 percent are inhibitory.

What are the four main types of glial cells in the central nervous system?

The four main types of glial cells are astrocytes, microglia, ependymal cells, and oligodendrocytes.

How does the ratio of glia to neurons vary?

The ratio of glia to neurons varies considerably from region to region in the brain.

What is the role of inhibitory neurons?

Inhibitory neurons send signals that suppress the activity of neighboring neurons and regulate circuit activity.

What is the role of calcium ions in neurotransmission?

Calcium ions flow into the cell when an action potential arrives, triggering the release of neurotransmitters from synaptic vesicles.

What is the synaptic cleft?

The synaptic cleft is the space between the end of an axon and the dendrite of an adjacent neuron.

What happens to the axon terminal membrane after neurotransmitter release?

After neurotransmitter release, pieces of the axon terminal membrane cycle back into the soma to be refilled with neurotransmitter molecules.

What is the significance of the separation between neurons?

The separation between neurons, verified by electron microscopy in the 1950s, is crucial for the proper functioning of synapses.

How do neighboring circuits influence a neuron's response?

The strength of signals from neighboring circuits can dynamically shift a neuron's response, allowing for flexible reactions.

What is the primary function of astrocytes in the brain?

Astrocytes form a network that regulates ion concentrations around neurons, provides nutrients, and helps regulate the formation of new connections between neurons.

What role do microglia play in the brain?

Microglia are the main immune cells of the brain, functioning as phagocytes to protect against infections and cellular damage, and they can also regulate the formation of new neuronal connections.

What is the function of ependymal cells?

Ependymal cells produce cerebrospinal fluid that cushions the brain inside the skull.

How do oligodendrocytes improve neuron function?

Oligodendrocytes wrap axons in a fatty sheath called myelin, which enhances neuron function.

What are neurotransmitters and what types of substances can act as them?

Neurotransmitters are chemical messengers that can include amino acids, gases, small organic chemicals, and short peptides.

What are the basic features of a neuron?

Neurons have a cell body containing the nucleus, dendrites that receive signals, and an axon that sends signals.

What is the role of dendrites in a neuron?

Dendrites are branched projections that extend from the cell body and collect incoming signals from other neurons at synapses.

What happens at the axon terminals of a neuron?

Axon terminals release neurotransmitters that transmit signals across synapses to other cells.