Biology Chapter 7 ChatGPT

What is the sensory homunculus?

A sensory map that visually represents the allocation of tissue in the primary somatic sensory area to various sensory functions.

What is the corpus callosum?

A substantial fiber tract that bridges the cerebral hemispheres.

What does the cerebrum do?

Covers and conceals a substantial portion of the brain stem.

Are sensory pathways crossed or uncrossed?

Crossed. The left side of the primary somatic sensory area interprets signals from the right side of the body and vice versa.

What is the function of satellite cells?

Cushion peripheral neuron cell bodies.

What are fissures?

Deeper grooves that further divide large regions of the brain.

What is cerebral white matter?

Deeper tissue in cerebral hemispheres characterized by fiber tracts.

What are dendrites and axons?

Dendrites receive signals, axons transmit signals.

What do gyri, sulci, and fissures help partition?

Each cerebral hemisphere into various lobes.

What is the somatic nervous system?

Enables conscious control of skeletal muscles.

Where is the primary motor area located?

Frontal lobe, anterior to the central sulcus.

What are nodes of Ranvier?

Gaps in the myelin sheath where nerve impulses are regenerated.

What functions are implicated in the anterior association area?

Higher intellectual reasoning, socially acceptable behavior, and language comprehension.

What happens when there is damage to Broca's area?

Inability to articulate words correctly while retaining understanding.

What happens when neurotransmitter molecules bind to receptors?

It generates a graded potential and, if sufficient, a nerve impulse.

How is the sensory homunculus organized?

It illustrates an inverted representation of the body, with areas rich in sensory receptors occupying substantial portions of the sensory area.

What is the weight of the adult human brain?

Just a little over 3 pounds.

What is an example of a somatic reflex?

Knee-jerk reflex

What is an axon?

Long fiber that carries nerve impulses away from the cell body.

What is the function of the cell body?

Metabolic center containing the nucleus, cytoplasm, Nissl bodies, and neurofibrils.

What does the brain stem consist of?

Midbrain, pons, and medulla oblongata.

What is the internal capsule?

A band of projection fibers between the thalamus and basal nuclei.

What is the longitudinal fissure?

A deep fissure that separates the cerebral hemispheres.

What triggers an action potential?

Adequate stimulation of the neuron.

What are the regions in the frontal lobes' anterior part called?

Anterior association area.

What is the appearance of the adult human brain?

Approximately two fistfuls of pinkish-gray tissue with a wrinkled appearance.

What do association fiber tracts connect?

Areas within a hemisphere.

How is the impulse conducted along the axon?

As an all-or-none response.

Where is Broca's area located?

At the base of the precentral gyrus.

Where is the speech area located?

At the junction of the temporal, parietal, and occipital lobes.

How are neurons classified?

Based on structural and functional criteria.

What does the motor homunculus represent?

Body areas with fine motor control, such as the face, mouth, and hands, in the motor cortex.

What are dendrites?

Branch-like extensions that receive signals from other neurons.

What happens when an action potential reaches an axon terminal?

Calcium channels open, leading to neurotransmitter release.

What is the function of the motor division?

Carries impulses from CNS to effector organs for motor responses.

What are the common features of neurons?

Cell body, dendrites, and axon.

What are oligodendrocytes?

Cells that form myelin sheaths around nerve fibers in the CNS.

What are the four major regions of the brain?

Cerebral hemispheres, diencephalon, brain stem, cerebellum.

What do projection fiber tracts link?

Cerebrum to lower centers in the central nervous system.

What are basal nuclei?

Clusters of gray matter in the cerebral hemispheres.

What are basal nuclei?

Clusters of gray matter within the cerebral hemispheres.

What does the primary motor area permit?

Conscious control of skeletal muscles.

What is the function of the cerebellum?

Coordination of voluntary movements and balance.

What do gyri, sulci, and fissures serve as?

Essential anatomical landmarks.

What is the function of the corpus callosum?

Facilitates communication between the cerebral hemispheres.

What is the function of the speech area?

Facilitates the pronunciation of words.

What are myelin sheaths?

Fatty coverings that protect and insulate nerve fibers.

What is myelin?

Fatty substance that insulates and speeds up nerve impulse conduction.

What are commissures?

Fiber tracts like the corpus callosum that connect different brain regions.

When do reflexes require brain involvement?

For sophisticated decision-making

What is the function of Schwann cells?

Form myelin sheaths around peripheral nerve fibers.

What is the role of basal nuclei?

Modulating voluntary motor activities, initiating or halting movements.

What is Broca's area?

Motor speech area in the brain.

What can altered reflexes indicate?

Nervous system dysfunction, even before other symptoms appear

What are ependymal cells?

Neuroglia lining the central cavities of the brain and spinal cord, facilitating cerebrospinal fluid circulation.

What are supporting cells in the CNS called?

Neuroglia or glial cells.

What is the electrochemical process that ensures signal transmission across synapses?

Neurotransmission

What cells produce myelin sheaths in the CNS?

Oligodendrocytes.

What is the brain stem?

One of the four major regions of the brain.

What is the cerebellum?

One of the four major regions of the brain.

What is the diencephalon?

One of the four major regions of the brain.

What is the cerebrum?

Paired cerebral hemispheres, the largest part of the brain.

Where is the primary somatic sensory area located?

Parietal lobe, behind the central sulcus.

What is the function of Broca's area?

Plays a pivotal role in speech production.

What are the electrical conditions of a resting neuron's membrane?

Polarized with fewer positive ions inside.

What are the major ions involved in the resting membrane potential?

Potassium (K+) inside and sodium (Na+) outside.

What happens during repolarization?

Potassium channels open, allowing potassium ions to leave the cell.

What does the primary somatic sensory area do?

Processes and localizes sensory input from the body's receptors, excluding those for special senses.

What is the function of astrocytes?

Provide structural support, regulate capillary permeability, and maintain the chemical environment in the brain.

What are gyri?

Raised ridges of tissue on the surface of the cerebrum.

What are reflexes?

Rapid, predictable, and involuntary responses to stimuli

What are the components of a reflex arc?

Receptors, sensory and motor neurons, an integration center, and an effector

What is the function of the posterior association area?

Recognizing patterns and faces, synthesizing diverse inputs.

What are somatic reflexes?

Reflexes involving skeletal muscles

What is the autonomic nervous system?

Regulates involuntary functions like smooth muscle activity, cardiac muscle, and glandular activity.

What are supporting cells in the PNS called?

Schwann cells and satellite cells.

What cells produce myelin sheaths in the PNS?

Schwann cells.

What is the function of neurons?

Serve as the primary communication units within the nervous system.

What are sulci?

Shallow grooves on the surface of the cerebrum.

What happens during action potential initiation?

Sodium channels open, allowing an influx of sodium ions.

How are reflexes categorized?

Somatic (involving skeletal muscles) or autonomic (regulating smooth muscles, the heart, and glands)

What functions does the cerebral cortex play?

Speech, memory, logical and emotional responses, consciousness, sensory interpretation, voluntary movement.

What are microglia?

Spider-like phagocytes that monitor neuron health and remove debris.

What are the three fundamental regions of each cerebral hemisphere?

Superficial cortex of gray matter, internal region of white matter, basal nuclei.

What are the two divisions of the autonomic nervous system?

Sympathetic and parasympathetic divisions.

Which lobes are involved in complex memory storage?

Temporal and frontal lobes.

What is depolarization?

Temporary change in membrane permeability due to sodium influx.

What does the diencephalon consist of?

Thalamus, hypothalamus, and epithalamus.

What are the lobes named after?

The cranial bones they sit beneath.

What is housed in the primary motor area?

The pyramidal tract, or corticospinal tract, which is the primary voluntary motor pathway.

What restores ion concentrations after repolarization?

The sodium-potassium pump.

What role do reflexes play in the body?

They maintain physiological processes and protect the body

What are the characteristics of more complex reflexes?

They may involve interneurons in the CNS and have longer response times

What are axon terminals?

They release neurotransmitters for communication.

How do neurons communicate?

Through neurotransmitters.

How do myelinated fibers conduct impulses?

Through saltatory conduction, leaping from node to node.

What is the purpose of polarization in a resting neuron?

To keep the neuron inactive.

What are neurons specialized for?

Transmitting nerve impulses.

Which cortical areas handle impulses from special sense organs?

Visual area in the occipital lobe, auditory area in the temporal lobe, olfactory area in the temporal lobe.

Can reflexes occur independently in the spinal cord?

Yes