Neuroscience: Neuron Function and Activity

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Questions and Answers

What effect do excitatory inputs have on the resting potential of a neuron?

They cause complete depolarization immediately.

They make it less negative. (correct)

They leave it unchanged.

They make it more negative.

What occurs during the refractory period of a neuron?

The neuron can fire another action potential immediately.

The neuron becomes more negative than its resting state. (correct)

Positive ions can enter the cell freely.

Sodium ions accumulate inside the cell.

Which type of neuron transmits messages from sensory receptors to the spinal cord and brain?

Motor neurons

Interneurons

Sensory neurons (correct)

Connector neurons

How fast can a neural impulse travel within a neuron?

Up to 360 km/h Signup and view all the answers

What happens to the neuron membrane during action potential?

It rapidly depolarizes to +40 millivolts. Signup and view all the answers

What is the primary function of neurons in the nervous system?

To receive and transmit electrochemical signals Signup and view all the answers

What do terminal buttons contain that are crucial for communication between neurons?

Synaptic vesicles Signup and view all the answers

How do neurotransmitters function in the synapse?

They act as chemical messengers between neurons Signup and view all the answers

What is the role of myelin in neuron function?

To facilitate the transmission of neural impulses Signup and view all the answers

Which part of the neuron is primarily responsible for receiving stimuli?

Dendrites Signup and view all the answers

What is contained within synaptic vesicles?

Neurotransmitters Signup and view all the answers

What does the axon do in the structure of a neuron?

Transmits electrical impulses to the terminal buttons Signup and view all the answers

Which of the following statements about neurons is incorrect?

All neurons connect to muscles for movement Signup and view all the answers

What structures make up the central nervous system (CNS)?

Brain and spinal cord Signup and view all the answers

Which system is responsible for controlling purposeful body movements?

Somatic nervous system Signup and view all the answers

What is the primary function of the sympathetic nervous system?

Prepare the body for fight or flight Signup and view all the answers

Which of the following describes the role of the parasympathetic nervous system?

Controls day-to-day operations of the body Signup and view all the answers

What is lateralization in the context of brain function?

The division of labor between the two hemispheres Signup and view all the answers

How does the spinal cord contribute to reflex actions?

It allows automatic reflexes without brain input. Signup and view all the answers

What is a key characteristic of the brain's structure?

It consists of interconnected neurons and glia. Signup and view all the answers

What is the main function of reflexes in the spinal cord?

To allow for quick reactions during survival situations Signup and view all the answers

What are neurotransmitters primarily responsible for in the nervous system?

Facilitating communication between neurons Signup and view all the answers

Which of the following statements about reuptake is accurate?

Reuptake helps to clear excess neurotransmitters from the synapse Signup and view all the answers

Which neurotransmitter is primarily associated with muscle action and memory?

Acetylcholine Signup and view all the answers

Which type of drug mimics or strengthens the effects of a neurotransmitter?

Agonist Signup and view all the answers

What is associated with low levels of dopamine?

Parkinson’s disease Signup and view all the answers

What role do synaptic vesicles play in neurotransmission?

They store neurotransmitters until they are released Signup and view all the answers

Which neurotransmitter is commonly linked to mood regulation and sleep?

Serotonin Signup and view all the answers

What does an antagonist do in the context of neurotransmission?

It inhibits the normal action of a neurotransmitter Signup and view all the answers

What is the function of the corpus callosum in the brain?

It connects the left and right hemispheres. Signup and view all the answers

Which hemisphere of the brain is primarily responsible for logical analysis and language?

Left hemisphere Signup and view all the answers

What are the roles of the thalamus in the forebrain?

Sensory relay Signup and view all the answers

What is Broca's area primarily associated with?

Language production Signup and view all the answers

Which lobe of the brain is involved in processing sensory and perceptual information?

Parietal lobe Signup and view all the answers

What is typically a result of a split-brain operation?

Inability for one hemisphere to communicate with the other Signup and view all the answers

Which structure of the brain is often referred to as the master gland of the endocrine system?

Pituitary gland Signup and view all the answers

What is the primary function of the motor cortex within the frontal lobe?

Planning and coordinating movement Signup and view all the answers

What primary function is attributed to the somatosensory cortex?

Processing sensory information from the body Signup and view all the answers

What is the primary role of Wernicke’s area in the brain?

Comprehending spoken language Signup and view all the answers

Which area of the brain is predominantly associated with memory and emotion?

Limbic system Signup and view all the answers

Which condition is a direct result of damage to Broca’s area?

Difficulty producing speech Signup and view all the answers

What role does the thalamus serve in the brain?

Process and relay sensory information Signup and view all the answers

The primary visual cortex is located in which part of the brain?

Occipital lobe Signup and view all the answers

What is the primary function of the substantia nigra?

Producing dopamine and controlling movement Signup and view all the answers

What impact does degeneration of the substantia nigra have on the body?

Movement control issues, such as those seen in Parkinson’s disease Signup and view all the answers

Study Notes

Introduction to Psychology 2E

Course title: Psychology 2E
Chapter: 3 Biopsychology
Textbook: OpenStax

The Nervous System

A network of nerves controlling various functions (thought, heartbeat, coordination, etc.).
Comprises the brain, spinal cord, and other components.
Enables receiving external information and responding to it.

Neurons

Specialized cells within the nervous system.
Transmit electrochemical signals (firing) between neighboring neurons.
Humans are born with over 100 billion neurons, mostly in the brain.

Neuron Structure

Cell body: Integrates information, receives stimulation.
Dendrites: Branch-like structures receiving stimulation.
Axon: Long, extended fiber transmitting signals.
Terminal buttons: Swollen bulb-like structures releasing neurotransmitters.

Myelin Sheath

Fatty substance insulating axons.
Speeds up signal transmission.
Damaged myelin is associated with multiple sclerosis, impacting neural impulse timing.

Parts of the Neuron

Dendrites: Branch-like structures extending from the cell body and receiving stimulation from sensory receptors or other neurons.
Cell Body (Soma): Contains the nucleus and DNA. Integrates information and passes signals to the axon. Can sometimes receive stimulation directly.
Axon: Long, extended fiber along which the neural impulse travels. Vary greatly in length, particularly in the spinal cord.
Terminal Buttons: Swollen bulb-like structures containing neurotransmitters, the chemical messengers.

The Synapse

The space between the terminal button of one neuron and the dendrite of another.
Neurotransmitters released into the synapse from vesicles bind to receptors on the neighboring neuron.
This either increases or decreases neuron activity.
Neurotransmitters not bound can be broken down or reabsorbed.

Neurotransmitters

Chemical substances transmitting information from one neuron to another.
Released by synaptic vesicles in axon terminals.
Bind to receptor sites on dendrites of receiving neurons.
Can be either excitatory or inhibitory.

Reuptake

Process of removing neurotransmitters from the synapse.
Neurotransmitters either drift away, are broken down, or reabsorbed.

Examples of Neurotransmitters

Acetylcholine: Affects muscle action and memory.
Beta-endorphin: Associated with pain and pleasure.
Dopamine: Related to mood, sleep, and learning.
Norepinephrine: Affects heart, intestines, and alertness.
Serotonin: Influences mood and sleep.

Drugs and Neurotransmitters

Psychotropic medications regulate neurotransmitter balance.
Agonist drugs mimic or strengthen neurotransmitter effects.
Antagonist drugs block or impede neurotransmitter activity.
Prescribed to correct imbalances.

Parts of the Nervous System

Central Nervous System (CNS): Consists of the brain and spinal cord.
Peripheral Nervous System (PNS): Contains somatic and autonomic divisions.
Nerves: Bundles of axons from many neurons.

Peripheral Nervous System

Somatic Nervous System: Controls purposeful body movements. Sensory and motor neurons transmit messages to and from the CNS.
Autonomic Nervous System: Regulates the glands and muscles of internal organs. Contains sympathetic and parasympathetic divisions.

Autonomic Nervous System

Sympathetic Nervous System: Activation during stress ("fight-or-flight"). Increases energy reserves for heightened senses and motor function.
Parasympathetic Nervous System: Activation during relaxed conditions ("rest-and-digest"). Calms the body after stress. Both systems complement each other to maintain homeostasis (body equilibrium).

The Brain and Spinal Cord

Brain: Composed of billions of interconnected neurons and glia. Bilateral (two-sided). Separable into lobes, though areas interact.
Spinal cord: Delivers messages to and from the brain and has reflex mechanisms. Sensory and motor nerves send messages between the brain and the body.

The Two Hemispheres

Lateralization: Each brain hemisphere specializes in specific functions.
Left hemisphere controls the right side of the body, often associated with logical analysis, language, and mathematical computation.
Right hemisphere controls the left side of the body, often associated with visual-spatial functions, facial recognition, and emotional understanding.

The Corpus Callosum

Connects the left and right hemispheres of the brain.
Crucial for communication and coordination between them.

Left Brain, Right Brain

Different functional responsibilities between the brain hemispheres, with some degree of overlap.

Split-Brain Experiments

Split-brain operations sever the corpus callosum in severe epilepsy cases.
This can lead to strange behaviors, with each hemisphere acting largely independently.

Forebrain, Midbrain & Hindbrain

Three major categories the brain can be divided into for functional analysis.

Forebrain Structures

Cerebral cortex: Higher-level processing, consciousness, thought, emotion, language, and memory.
Thalamus: Sensory relay center.
Hypothalamus: Homeostasis.
Pituitary gland: Master gland of the endocrine system.
Limbic system: Emotion and memory circuitry.

Lobes of the Brain

Frontal Lobe: Executive functions, planning, judgment, attention, reasoning, motor control, emotion, language.
Parietal Lobe: Processes sensory and perceptual information (touch, temperature, pain).
Temporal Lobe: Associated with hearing, memory, and language (auditory cortex, Wernicke's area).
Occipital Lobe: Associated with visual processing (primary visual cortex).

Language Functions

Two key areas—Broca's and Wernicke's area in the left hemisphere.
Damage to these areas results in aphasia, difficulty understanding or producing language.

The Thalamus

Serves as a relay center for most sensory information (excluding smell) before it's directed to other brain areas for processing.

The Limbic System

Mediates emotional responses and memory.
Amygdala: Processes emotion, particularly fear.
Hippocampus: Crucial for learning, memory especially spatial memory.
Hypothalamus: Regulates homeostasis, including body temperature, appetite, and blood pressure.

The Midbrain

Reticular formation: Regulates sleep/wake cycles, alertness, and motor activity.
Substantia nigra, Ventral tegmental area (VTA): Dopamine production, involved in movement, mood, reward, and addiction. Damage affects Parkinson's disease.

The Hindbrain

Medulla: Controls automatic processes like breathing and heart rate.
Pons: Connects the brain and spinal cord and involved in regulating brain activity during sleep.
Cerebellum: Coordinates movement, motor skills, balance, and is involved in certain types of memory.

The Endocrine System

A network of glands regulating body functions through hormones.
Hypothalamus links nervous and endocrine systems via the pituitary gland.
Pituitary gland: Master gland controlling other glands' hormone secretion.
Thyroid: Affects growth, metabolism, and appetite.
Adrenal glands: Secrete hormones in response to stress.
Gonads: Produce sex hormones, crucial for reproduction and sexual motivation.
Pancreas: Regulates blood sugar.

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Test your knowledge on neuronal function with this quiz that covers excitatory inputs, the refractory period, and the types of neurons involved in message transmission. Dive deeper into the mechanics of action potential and the speed of neural impulses. Perfect for neuroscience students and enthusiasts!