Neuroscience Quiz: Nervous System Functions
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Questions and Answers

What is the primary role of the corticospinal tract?

  • Transmitting pain signals
  • Controlling voluntary movements of the limbs (correct)
  • Carrying sensory information from the body
  • Regulating autonomic functions

    • What triggers the triceps reflex?

  • Stretching the muscle
  • Tapping the triceps tendon (correct)
  • Painful pressure on the forearm
  • Electrical stimulation

    • What do synaptic knobs contain?

  • Neurotransmitters in synaptic vesicles (correct)
  • Cellular organelles for energy production
  • Axon terminals for signal reception
  • Myelin sheaths for signal insulation

    • What is the consequence of crossover of sensory nerve fibers?

    <p>Contralateral sensation processed in the opposite hemisphere</p> Signup and view all the answers

    What effect do EPSPs have on the postsynaptic membrane?

    <p>Depolarization of the membrane</p> Signup and view all the answers

    What are the primary functions of cerebrospinal fluid (CSF)?

    <p>Cushioning the brain and removing waste</p> Signup and view all the answers

    What type of neurotransmitter is released by adrenergic fibers?

    <p>Norepinephrine</p> Signup and view all the answers

    What is the functional unit of muscle contraction?

    <p>Sarcomere</p> Signup and view all the answers

    What causes rigor mortis after death?

    <p>Depletion of ATP preventing myosin detachment from actin</p> Signup and view all the answers

    Which statement correctly describes the characteristics of skeletal muscle?

    <p>Striated, voluntary, and multinucleated</p> Signup and view all the answers

    What is the minimal stimulus required to initiate an action potential in a neuron?

    <p>Threshold stimulus</p> Signup and view all the answers

    Which type of muscle is found in the heart?

    <p>Cardiac muscle</p> Signup and view all the answers

    What is the sequence of events in the propagation of an action potential?

    <p>Depolarization, Repolarization, Saltatory Conduction</p> Signup and view all the answers

    Where are neurotransmitters stored in a neuron?

    <p>Synaptic vesicles in synaptic knobs</p> Signup and view all the answers

    Which nervous system controls voluntary muscle movements?

    <p>Somatic Nervous System (SNS)</p> Signup and view all the answers

    What occurs during the relaxation phase of muscle contraction?

    <p>Myosin heads detach from actin</p> Signup and view all the answers

    What is the primary function of Broca's area in the brain?

    <p>Producing coherent speech</p> Signup and view all the answers

    Which component is primarily responsible for the quick regeneration of ATP during intense muscular activity?

    <p>Creatine phosphate</p> Signup and view all the answers

    What type of brain waves are associated with deep sleep?

    <p>Delta waves</p> Signup and view all the answers

    Which of the following structures is NOT part of the diencephalon?

    <p>Cerebrum</p> Signup and view all the answers

    How do axons in the peripheral nervous system (PNS) differ from those in the central nervous system (CNS) regarding regeneration?

    <p>PNS axons regenerate more effectively due to the presence of Schwann cells.</p> Signup and view all the answers

    What happens to the brain's receptors over time when exposed to drugs contributing to drug tolerance?

    <p>Receptor desensitization or downregulation</p> Signup and view all the answers

    What is the composition of myofibrils in muscle cells?

    <p>Repetitions of sarcomeres made of actin and myosin</p> Signup and view all the answers

    Which process takes place in myelinated axons that enhances the speed of impulse conduction?

    <p>Saltatory conduction</p> Signup and view all the answers

    What is the primary function of the dura mater?

    <p>Provides a tough and protective outer layer</p> Signup and view all the answers

    Which type of muscle contraction is characterized by a steady level of tension?

    <p>Tonic contraction</p> Signup and view all the answers

    What is gray matter primarily composed of?

    <p>Neuron cell bodies and dendrites</p> Signup and view all the answers

    What role do agonists play in muscle movement?

    <p>They are responsible for primary actions in a movement</p> Signup and view all the answers

    Which component of a reflex arc processes the information received from sensory neurons?

    <p>Integration Center</p> Signup and view all the answers

    What separates the left and right hemispheres of the brain?

    <p>Longitudinal fissure</p> Signup and view all the answers

    What primarily composes white matter in the brain?

    <p>Myelinated axons</p> Signup and view all the answers

    What area of the nervous system is responsible for innervating the diaphragm for breathing?

    <p>Phrenic nerve plexus</p> Signup and view all the answers

    What is the function of the crossed extensor reflex?

    <p>To extend the opposite limb for balance</p> Signup and view all the answers

    Which component of a neuron is responsible for processing information?

    <p>Cell Body (Soma)</p> Signup and view all the answers

    What effect does recruitment have on motor units?

    <p>Increases the number of motor units activated</p> Signup and view all the answers

    Which type of neuron has only one axon and one dendrite?

    <p>Bipolar neuron</p> Signup and view all the answers

    What is the main role of myelin in the nervous system?

    <p>Insulates axons to enhance impulse conduction</p> Signup and view all the answers

    How does acetylcholine get degraded in the synaptic cleft?

    <p>By acetylcholinesterase</p> Signup and view all the answers

    What type of muscle is engaged in generating heat, particularly during shivering?

    <p>Skeletal muscle</p> Signup and view all the answers

    Which area of the brain is primarily associated with the language disorder known as aphasia?

    <p>Wernicke's area</p> Signup and view all the answers

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

    <p>To serve as the connection between neurons for signal transmission</p> Signup and view all the answers

    Which of the following statements regarding muscle origins and insertions is true?

    <p>The origin is the fixed attachment point of a muscle.</p> Signup and view all the answers

    Which type of cell is NOT found in the central nervous system (CNS)?

    <p>Schwann cells</p> Signup and view all the answers

    What is a primary characteristic of a motor unit?

    <p>It consists of one motor neuron and all the muscle fibers it innervates.</p> Signup and view all the answers

    Which sequence correctly describes the steps following a threshold potential in a neuron?

    <p>Sodium channels open, potassium channels open, and sodium-potassium pump restores resting potential.</p> Signup and view all the answers

    What is the main role of the basal ganglia within the cerebrum?

    <p>Controlling voluntary motor movements and learning procedures</p> Signup and view all the answers

    Which connective tissue layer surrounds individual nerve fibers?

    <p>Endoneurium</p> Signup and view all the answers

    What is the threshold stimulus in nerve cells?

    <p>The minimum stimulus required to depolarize the membrane and generate an action potential</p> Signup and view all the answers

    Study Notes

    Corticospinal Tract

    • Major neural pathway in the central nervous system (CNS)
    • Carries motor commands from the brain's motor cortex to the spinal cord
    • Located in white matter of brain and spinal cord
    • Controls voluntary movements, especially fine motor movements of limbs and hands

    Triceps Reflex Movements

    • Monosynaptic reflex
    • Triggered by tapping the triceps tendon
    • Causes the triceps brachii muscle to contract, extending the forearm

    Synaptic Knobs

    • Terminal ends of axons
    • Contain synaptic vesicles filled with neurotransmitters
    • Release neurotransmitters into the synaptic cleft to transmit signals

    Sensory Nerve Fiber Crossover

    • Results in contralateral (opposite side) sensation
    • Sensory information from one side of the body is processed in the opposite side of the brain

    EPSPs and IPSPs

    • EPSPs (excitatory postsynaptic potentials) depolarize the postsynaptic membrane, increasing the likelihood of an action potential
    • IPSPs (inhibitory postsynaptic potentials) hyperpolarize the membrane, making an action potential less likely

    Cerebrospinal Fluid (CSF)

    • Clear fluid produced by choroid plexus in brain ventricles
    • Cushions the brain and spinal cord
    • Removes waste
    • Maintains chemical stability of the CNS

    Adrenergic Fibers

    • Release norepinephrine (noradrenaline) as a neurotransmitter
    • Found in the sympathetic nervous system
    • Regulate functions like heart rate and blood pressure

    Transmission of Impulses Between Neurons

    • Neurotransmitters released from presynaptic neuron into synaptic cleft
    • Neurotransmitters bind to receptors on postsynaptic neuron, triggering an excitatory or inhibitory signal

    Functional Unit of Muscle Contraction

    • Sarcomere, segment between two Z-lines in a myofibril
    • Contains actin and myosin filaments
    • Interaction of these filaments is responsible for muscle contraction

    Rigor Mortis

    • Muscle stiffening after death
    • Occurs because ATP is unavailable to detach myosin from actin, keeping muscles contracted

    Threshold Stimulus

    • Minimal stimulus required
    • Causes a neuron to reach its threshold potential, generating an action potential

    Muscle Characteristics

    • Skeletal Muscle: Striated, voluntary, multinucleated, attached to bones
    • Smooth Muscle: Non-striated, involuntary, single-nucleated, in organs like intestines and blood vessels
    • Cardiac Muscle: Striated, involuntary, single or binucleated, found in the heart

    Action Potential Steps

    • Depolarization: Na+ channels open, Na+ rushes into the cell
    • Repolarization: K+ channels open, K+ exits the cell
    • Saltatory Conduction: Action potentials "jump" along myelinated axons

    Synapse

    • Junction between two neurons or neuron and another cell type
    • Neurotransmitters are released to transmit signals

    Somatic and Autonomic Nervous Systems

    • Somatic Nervous System (SNS): Controls voluntary muscle movements
    • Autonomic Nervous System (ANS): Controls involuntary functions like heart rate and digestion

    Striated Skeletal Muscles

    • Appear striated due to actin and myosin filaments arrangement in sarcomeres

    Events of Muscle Contraction

    • Excitation (nerve impulse triggers acetylcholine release)
    • Action Potential Propagation (impulse travels along muscle fiber and into T-tubules)
    • Calcium Release (calcium ions released from sarcoplasmic reticulum)
    • Cross-Bridge Formation (myosin heads attach to actin)
    • Relaxation (calcium reabsorbed, muscle relaxes)

    Reticular Formation

    • Involved in regulating wakefulness, sleep cycles, and attention
    • Controls some reflexes

    ATP and Creatine Phosphate

    • Creatine phosphate acts as a quick energy source converting ADP back to ATP during intense muscular activity

    Forebrain Development

    • Develops into structures involved in higher brain functions (cerebrum, thalamus, hypothalamus) such as cognition, emotion, and sensory processing

    Broca's Area

    • Involved in speech production
    • Located in the left frontal lobe

    Brain Waves

    • Record electrical activity in the brain
    • Classified as delta, theta, alpha, and beta waves

    Axon Regeneration Differences

    • Axons in the peripheral nervous system (PNS) regenerate better than those in the CNS

    Drug Tolerance

    • Brain adjusts to neurotransmitter alterations caused by drugs
    • Reduced drug efficacy due to receptor desensitization or downregulation

    Muscle Fiber Composition

    • Myofibrils are made of repeating units called sarcomeres, composed of actin (thin) and myosin (thick) filaments

    Bones and Muscles as Mechanical Devices

    • Bones act as levers, joints are pivot points, muscles provide force for movement

    Major Parts of the Diencephalon

    • Includes thalamus, hypothalamus, epithalamus, and subthalamus
    • Regulate sensory processing, autonomic functions, and emotional responses

    Rapid Conduction in Axons

    • Most rapid conduction in myelinated axons where action potential "jumps" between nodes of Ranvier.

    Meningitis Effects

    • Inflammation of the meninges (protective layers surrounding brain and spinal cord), potentially damaging the CNS

    Neuronal Pools

    • Interneurons organize into neuronal pools to integrate and process signals

    Meningeal Layers

    • Dura Mater (outermost layer), tough and protective, containing cerebrospinal fluid
    • Arachnoid Mater (middle layer)
    • Pia Mater (innermost layer) closely adhered to brain and spinal cord

    Partial Sustained Contraction

    • Tonic contraction where muscles maintain a steady level of tension (e.g. postural muscles)

    Brain Area for Voluntary Movements

    • Cerebellum coordinates voluntary movements, balance, and fine motor skills

    Gray and White Matter

    • Gray matter: neuron cell bodies, dendrites, unmyelinated axons (processing and integration)
    • White matter: myelinated axons(transmit signals over long distances)

    Dermatome

    • Area of skin innervated by sensory fibers from a single spinal nerve (helps to localize nerve damage)

    Neurotransmitter Release

    • Neurotransmitters released from synaptic vesicles via exocytosis when an action potential reaches the synaptic terminal

    Agonists, Antagonists, and Prime Movers

    • Agonists: Chemicals activating receptors
    • Antagonists: Chemicals blocking receptor activity
    • Prime movers: Muscles responsible for the primary action in a movement

    Muscle Contraction (Rapid Stimuli)

    • Individual twitches combine through summation
    • Strong, smooth contraction without relaxation if stimuli are frequent

    Reflex Arc Components

    • Receptor: detects a stimulus
    • Sensory Neuron: sends signal to CNS
    • Integration Center: CNS processes information
    • Motor Neuron: sends response from CNS to effector
    • Effector: executes response, such as a muscle or gland

    Brain Fissures

    • Longitudinal Fissure: divides left and right hemispheres
    • Central Sulcus: Divides frontal and parietal lobes
    • Lateral/Sylvian Fissure: Separates temporal from frontal and parietal lobes
    • Transverse Fissure: Separates cerebrum from cerebellum

    Phrenic Nerve Plexus

    • Innervates the diaphragm for breathing
    • Arises from cervical plexus (C3-C5)

    CNS vs. PNS

    • CNS: Brain and spinal cord
    • PNS: Cranial nerves, spinal nerves, and peripheral nerves

    Crossed Extensor Reflex

    • Complements the withdrawal reflex for maintaining balance

    Neuron Structure and Function

    • Dendrites: receive signals
    • Cell body/soma: contains nucleus and processes info
    • Axon: conducts impulses
    • Axon terminals: release neurotransmitters

    Muscle Cell Structure and Function

    • Sarcolemma: muscle cell membrane
    • Myofibrils: contain actin and myosin for contraction
    • Sarcoplasmic reticulum: stores and releases calcium for contraction

    Motor Unit Recruitment

    • Increasing the number of motor units activated in response to intense stimulation

    Drugs Inhibiting Monoamine Oxidase

    • Increase availability of neurotransmitters, such as serotonin, norepinephrine, and dopamine

    Myelin

    • Lipid rich sheath surrounding axons
    • Increases nerve impulse conduction speed

    How Myelin is Produced

    • Schwann cells (PNS) and Oligodendrocytes (CNS)

    Gray and White Matter in Spinal Cord

    • Anterior Horn: Motor neurons
    • Posterior Horn: Sensory neurons
    • Lateral Horn: Autonomic neurons

    Types of Neurons

    • Bipolar: single axon and dendrite
    • Unipolar: single process splitting into two
    • Multipolar: many dendrites, one axon

    Acetylcholine Degradation

    • Acetylcholinesterase breaks down acetylcholine in the synaptic cleft

    Skeletal Muscle and Body Temperature

    • Skeletal muscle contractions generate heat to maintain body temperature

    Neuron Characteristics

    • Excitability: Responds to stimuli
    • Conductivity: Transmit electrical impulses
    • Secretion: Release neurotransmitters

    Aphasia

    • Language disorder caused by brain damage (e.g., affecting speech, comprehension)

    Cerebral Association Areas

    • Integrate sensory input, memory, reasoning, and emotions to enable complex tasks

    Functional Connection Between Neurons

    • Synapse serves as connections between neurons allowing signal transmission via neurotransmitters

    Functions of Neurons

    • Sensory Neurons: Carry signals to CNS
    • Motor Neurons: Carry signals from CNS to effectors
    • Interneurons: Integrate information within CNS

    Muscle Origin and Insertion

    • Origin: fixed attachment point
    • Insertion: movable attachment point

    CNS and PNS Cells

    • CNS: astrocytes, oligodendrocytes, microglia, ependymal cells
    • PNS: Schwann cells, satellite cells

    Spinal Nerve Injuries

    • Result from trauma, compression (e.g., herniated disc, inflammation)
    • Can cause motor or sensory deficits

    Neuromuscular Junction (NMJ)

    • Where motor neuron meets muscle fiber
    • Acetylcholine released to trigger muscle contraction

    Motor Unit

    • Motor neuron and all muscle fibers it innervates
    • Consists of a motor neuron and all the muscle fibers it innervates

    Threshold Stimulus

    • Minimum stimulus needed to depolarize the membrane and generate an action potential (causes an action potential)

    Convergence and Divergence

    • Convergence: Multiple neurons signal to one neuron
    • Divergence: One neuron signals to multiple neurons

    Connective Tissue Layers

    • Muscle cells: Epimysium (entire muscle), perimysium (fascicles), endomysium (individual fibers)
    • Nerve cells: Epineurium (entire nerve), perineurium (fascicles), endoneurium (individual fibers)

    Steps After Threshold Potential

    • Sodium channels open (depolarization)

    Potassium Channels and Sodium Potassium Pumps

    • Potassium channels open for repolarization
    • Sodium-potassium pump restores resting potential
    • Neuron Cell Bodies in PNS: Clusters called ganglia

    Basal Ganglia Location and Function

    • Located in cerebrum
    • Control voluntary motor movements, procedural learning, and habits

    Cerebral Cortex

    • Outer layer of gray matter
    • Involved in higher brain functions

    Hemispheric Dominance

    • One hemisphere (usually left) controlling language and analytical tasks

    Limbic System

    • Regulates emotions and memory

    Na+ and K+ in Neurons

    • Na+ enters the neuron during depolarization
    • K+ exits the neuron during repolarization
    • Sodium-potassium pump restores ionic balance

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    Description

    Test your knowledge on the functions and anatomy of the nervous system with this quiz. Explore key concepts such as the corticospinal tract, reflexes, and neurotransmitter roles. Perfect for students studying neuroscience or related fields.

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