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Anatomy & Physiology: Nervous System Quiz

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Termini in questo insieme (28)

  • What does Myelinate mean?

    biological process of forming a protective lipid-protein insulation layer (myelin) around neuronal axons

  • What are the three main functions of the nervous system?

    Sensory input (gathering information)

    Integration (processing information)

    Motor output (activating effectors like muscles or glands).

  • What structures make up the Central Nervous System (CNS)?
    The brain and spinal cord, responsible for integrating, processing, and coordinating sensory data and motor commands.
  • What is the Peripheral Nervous System (PNS)?
    All nerves and neural tissues outside the CNS, including cranial nerves, spinal nerves, and ganglia.
  • What are the two functional divisions of the PNS?

    Sensory (afferent) division conveys impulses to the CNS;

    Motor (efferent) division transmits impulses from CNS to effectors.

  • Differentiate between the somatic and autonomic nervous systems.
    The somatic nervous system controls voluntary movements; the autonomic nervous system controls involuntary functions.
  • What are the two subdivisions of the autonomic nervous system?
    Parasympathetic (rest and digest) and sympathetic (fight or flight) systems.
  • What is a neuron?
    A nerve cell that conducts messages via nerve impulses between parts of the body.
  • What is the role of Schwann cells and oligodendrocytes?
    Schwann cells myelinate PNS neurons; Oligodendrocytes myelinate CNS neurons.
  • Name four types of neuroglia in the CNS and their functions.
    Astrocytes support neurons and maintain blood-brain barrier; Microglia act as macrophages; Ependymal cells circulate cerebrospinal fluid; Oligodendrocytes form myelin sheaths.
  • What is the resting membrane potential of a neuron?
    Approximately \(-70\,mV\), due to ionic differences across the membrane.
  • Why is the resting membrane potential negative inside the neuron?
    Because the membrane is more permeable to K+ than Na+, and large anionic proteins inside the cell cannot cross the membrane.
  • What is the function of the Na+/K+ pump?
    It pumps 3 Na+ out and 2 K+ in, maintaining ionic gradients and stabilizing the resting membrane potential.
  • Classify neurons based on structure.
    Multipolar, bipolar, unipolar, and anaxonic neurons, based on the number of processes.
  • Classify neurons based on function.
    Afferent (sensory) neurons carry impulses to CNS; Efferent (motor) neurons carry impulses away from CNS; Interneurons connect neurons within CNS.
  • What is a graded potential?
    A short-term, local change in membrane potential that varies in magnitude and can be excitatory or inhibitory.
  • What is an action potential?
    A large, brief reversal of membrane potential that propagates along a neuron without losing amplitude.
  • What is the threshold potential for generating an action potential?
    Approximately \(-55\,mV\); crossing this opens voltage-gated Na+ channels.
  • What factors increase the speed of action potential conduction?
    Myelination and axon diameter (thicker axons conduct faster).
  • What is saltatory conduction?
    The jumping of action potentials between nodes of Ranvier along a myelinated axon.
  • What is the difference between EPSP and IPSP?
    EPSP (excitatory postsynaptic potential) depolarizes the membrane; IPSP (inhibitory postsynaptic potential) hyperpolarizes it.
  • What is synaptic summation?
    The process by which multiple graded potentials combine at the axon hillock to trigger an action potential.
  • What are the two types of synaptic summation?
    Temporal summation (multiple signals from one neuron in rapid succession) and spatial summation (signals from multiple neurons).
  • How is neurotransmitter removed from the synaptic cleft?
    By reuptake into presynaptic terminals or astrocytes, enzymatic degradation, and diffusion away from the synapse.
  • What is acetylcholine's role in the nervous system?
    It is an excitatory neurotransmitter at neuromuscular junctions and inhibitory on cardiac cells.
  • How does acetylcholine act excitatory at neuromuscular junctions?
    By binding to nicotinic receptors, allowing Na+ and K+ movement, creating an EPSP.
  • How does acetylcholine act inhibitory on cardiac cells?
    By binding to muscarinic receptors, opening K+ channels and creating an IPSP.
  • What enzyme breaks down acetylcholine in the synapse?
    Acetylcholinesterase, which breaks acetylcholine into acetic acid and choline.