Nervous System Quiz

Central Nervous System (CNS)

• CNS comprises the brain and spinal cord.

Peripheral Nervous System (PNS)

• PNS connects the CNS to the rest of the body.
• Somatic Nervous System:
  • Transmits sensory information and controls voluntary movement.
  • Sensory (sensation)
  • Motor (muscle contraction, movement)
  • Via spinal nerves (spinal cord)
  • Via cranial nerves (brainstem)
• Autonomic Nervous System:
  • Maintains essential bodily functions without conscious control.
  • Breathing, pupil dilation, sexual arousal, swallowing, digestion
  • Sympathetic ("fight or flight")
  • Parasympathetic ("rest and digest")

Neurons

• Fundamental units of the nervous system.
• Cell body: Maintains the cell (metabolism).
• Axon: Myelin-coated fiber carrying electrical impulses.
• Dendrite: Receives neurotransmitters for communication.

Types of Neurons

• Multipolar
• Pyramidal
• Purkinje
• Bipolar
• Unipolar

Neuronal Communication

• Action potential: Electrical signal traveling down the axon.
• Ion channels allowing ions to flow, creating a negative charge inside the axon and a positive charge outside.
  • Sodium and potassium channels are closed when the neuron is at rest.
• Depolarization: Temporary shift in membrane potential (negative to positive) due to action potential.
• Communication via synapses (where neurons meet).
• Action potential triggers neurotransmitter release into the synaptic cleft.
• Neurotransmitters bind to specific receptors on the receiving neuron.
• Receptors are neurotransmitter-specific, activated only by their corresponding neurotransmitter or by a chemical that mimics it.

Synapses

• Postsynaptic receptors, when activated, open ion channels.
• Enzymes break down free neurotransmitters.
• Neurotransmitters are reabsorbed by the axon terminal.

Drug Action

• Drugs affect neurotransmission in various ways.
  • SSRIs block serotonin reuptake.
  • Agonists mimic neurotransmitters to trigger receptors.
  • Antagonists block receptors.
  • Some drugs directly affect ion channels

Biological Factors Affecting Neurons

• Proteins can malfunction (e.g., Alzheimer's).
• Cell generation, regeneration, and metabolism are crucial (neurodevelopment, stem cells).
  • Other aspects of body's metabolism (oxygen, glucose, hormones, nutrients) are also important

Brain Structure

• Grey matter: Cell bodies (brain's computation centers).
• White matter: Axons (brain's cabling).
• Fatty tissue gives white matter its color.
• Cortex: Outer layer of grey matter, highly folded for increased surface area, responsible for higher cognitive functions.

Neuroplasticity

• Brain's ability to change structure/function due to experience.
• Synaptic plasticity: Changes in connection strengths between synapses.
• Synaptogenesis and synaptic pruning: Creation and removal of synapses.
• Neurogenesis: Creation of new neurons.
• Neuronal migration: Neurons moving from their origin to their destination.
• Neural cell death (damage, over-excitation, disease, apoptosis).
• Functional reorganization: Redistributing brain functions (e.g., blind person reading braille).
• Practice can reduce brain activity associated with a task.

Neuroscience Methods

• Direct interventional studies (drugs, lesions, genetic changes, electrical stimulation).
• Measurement of brain tissue (in vivo, post-mortem).
• Indirect examination (neuroimaging).
• Behavioral/performance testing, experience (symptoms).

Neurobiology

• Study of the biological processes in the nervous system.
• Includes neuronal signaling, cell physiology, genetics, interventions, and pathologies.

Systems Neuroscience

• Study of neural networks, from small groups of neurons to large-scale circuits.

Psychopharmacology

• Study of substances that affect mental states.
• Includes medications (e.g., antipsychotics affect dopamine receptors), common drugs (e.g., caffeine, nicotine), street drugs (e.g., MDMA, LSD), and industrial chemicals (e.g., toluene).

Neuropsychology

• Study of how brain structure and function relate to thoughts, feelings, and behaviors.
• Standardized tests and experimental tasks.
• Examines cognition (e.g., left-sided hemi spatial neglect).

Cognitive Neuroscience

• Study of the neural correlates of thoughts, emotions, and behaviors.
• Usually involves neuroimaging techniques and transcranial magnetic stimulation (TMS).

Test your knowledge on the components of the central and peripheral nervous systems, including neurons and their types. This quiz covers essential functions and structures involved in the nervous system. Perfect for students studying biology or neuroscience.