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Anatomy & Physiology: Nervous System and Brain Terminology

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Termini in questo insieme (32)

  • What is a fissure in the brain?
    A fissure is a deep groove that separates major regions of the brain, such as the longitudinal fissure separating the right and left cerebral hemispheres.
  • Difference between gyrus, sulcus, and fissure
    Gyrus: raised ridge or fold; Sulcus: shallow groove between gyri; Fissure: deep groove separating major brain regions.
  • What is a nerve plexus?
    A nerve plexus is a network of interwoven spinal nerves that redistribute nerve fibers to different peripheral nerves.
  • Function of a nerve plexus
    A plexus allows nerve fibers from multiple spinal nerves to mix, providing multiple pathways for motor and sensory innervation.
  • Location of the brachial plexus
    The brachial plexus is formed by spinal nerves \(C5–T1\) and supplies the shoulder, arm, forearm, and hand.
  • Location of the lumbar plexus
    The lumbar plexus is formed by spinal nerves \(L1–L4\) and supplies parts of the abdomen, pelvis, and anterior thigh.
  • Why are plexuses important?
    Plexuses allow nerves from different spinal cord levels to combine, providing backup pathways and efficient distribution of nerve fibers.
  • First step in processing sensory information
    A receptor detects a stimulus.
  • What carries sensory information toward the CNS?
    A sensory (afferent) neuron carries information to the central nervous system.
  • What is the integration center?
    The integration center is the CNS (brain or spinal cord) where incoming information is processed and a response is determined.
  • What carries the response away from the CNS?
    A motor (efferent) neuron carries the response to an effector.
  • What is an effector?
    An effector is a muscle or gland that performs the response directed by the nervous system.
  • Correct order of information processing
    Stimulus → Receptor → Sensory (afferent) neuron → Integration center (CNS) → Motor (efferent) neuron → Effector → Response
  • Difference between myelinated and unmyelinated axons
    Myelinated axons have a myelin sheath and conduct impulses faster than unmyelinated axons.
  • Why do myelinated axons conduct impulses faster?
    Impulses jump from one Node of Ranvier to the next in a process called saltatory conduction.
  • What is saltatory conduction?
    Rapid transmission of an action potential by jumping between Nodes of Ranvier.
  • How does conduction occur in unmyelinated axons?
    The action potential travels continuously along the entire membrane, making conduction slower.
  • Which nerve fibers conduct impulses faster?
    Myelinated nerve fibers conduct impulses faster than unmyelinated fibers.
  • What happens during depolarization?
    Voltage-gated sodium (Na⁺) channels open, allowing sodium ions to enter the neuron.
  • What happens during repolarization?
    Voltage-gated potassium (K⁺) channels open, allowing potassium ions to leave the neuron.
  • Which ion enters the neuron first during an action potential?
    Sodium (Na⁺) enters first during depolarization.
  • Which ion leaves the neuron during repolarization?
    Potassium (K⁺) leaves the neuron during repolarization.
  • Why is sodium important in an action potential?
    Sodium entry causes the membrane to become less negative and more positive, producing depolarization.
  • Why is potassium important in an action potential?
    Potassium exit restores the membrane toward its resting potential during repolarization.
  • What is an afferent pathway?
    An afferent pathway carries sensory information toward the central nervous system.
  • What type of neuron is in the afferent pathway?
    A sensory neuron is found in the afferent pathway.
  • What is an efferent pathway?
    An efferent pathway carries motor commands away from the CNS to muscles or glands.
  • What type of neuron is in the efferent pathway?
    A motor neuron is found in the efferent pathway.
  • How many pairs of cranial nerves are there?
    There are twelve pairs of cranial nerves (CN I–XII).
  • Function of Cranial Nerve I (Olfactory)
    Responsible for smell (sensory).
  • Function of Cranial Nerve II (Optic)
    Responsible for vision (sensory).
  • Function of Cranial Nerve III (Oculomotor)
    Controls most eye movements, raises eyelid, and constricts pupil (motor).