Lesson 4: Synapses, Drugs, and Addictions

Cards (15)

  • It emerges from segments of the spinal cord.

    SPINAL NERVES
  • 31 PAIRS OF SPINAL NERVES
    • 8 cervical pairs
    • 12 thoracic pairs
    • 5 lumbar pairs
    • 5 sacral pairs
    • 1 coccygeal spinal nerve
  • FOUR (4) MAJOR PLEXUSES
    • Cervical plexus (C1-C4) - innervates neck.
    • Branchial plexus (CS-T1) - innervates upper limb.
    • Lumbar plexus (11-14) - innervates the lower abdominal wall, anterior hip and thigh.
    • Sacral plexus (L4-54) - innervates the pelvis and the lower limb.
  • SYMPATHETIC NERVOUS SYSTEM
    • Nerve fibers have thoracolumbar origin that they stem from the T1-L2/L3 spinal cord segments.
    • They synapse with prevertebral and paravertebral ganglia.
  • PARASYMPATHETIC NERVOUS SYSTEM

    • "Rest and digest" or "feed and breed" activities.
    • The nerves of this system slow down cardiovascular system, divert blood away from muscles and increase peristalsis and gland secretion.
    • The fibers have craniosacral flow (2):
    • Brainstem (cranio).
    • S2-S4 spinal cord segments (sacral).
  • Electrical signal
    The form information takes inside neurons, and it forms _____ signal.
  • Chemical signal
    The form information takes to cross the tiny gap, or synapse, that separates one neuron from the next, the information takes the form of a ______ signal.
  • Neurotransmitter
    The specialized molecules that carry the signals across the synapses are called _______. Relay information about the environment and our states from neuron to neuron through brain circuits and shape how we respond.
  • Neurotransmission
    The process by which signaling molecules called ________ are released by the axon terminal of a neuron (the presynaptic neuron) and bind to and react with the receptors on the dendrites of another neuron (the postsynaptic neuron) a short distance away.
  • If neurotransmitters are loose again in the synapse they will meet one of three fates:

    • Attach to another receptor.
    • Encounter enzyme (chemical breaks them apart).
    • Transporter (reenter the sending neuron via special structure that spans the neuron membrane).
  • Chronic Drug Use
    • Change in neuronal structure and function causing long-term effect in neurotransmission abnormalities.
    • Can prod some genes to increase or decrease their production of proteins, leading to changes in neuron function or even actual reshaping of the physical structure of neurons.
    • Toxic to neurons and effects accumulate with repeated exposures.
  • Chronic drug use effects
    • In mice, the cocaine alters important genetic transcription factors and expressions of hundreds of genes. Some of the resulting changes in the brain's complement of proteins have been associated with increased drug-seeking and addiction-like behaviors in animals. Other changes such as proliferation of new dendrites may be compensatory.
    • Some epigenetic changes can be passed down to next generation, like an offspring of rats exposed to TCH (main psychotropic component of marijuana) have alterations in glutamate and cannabinoid receptor formation that affects their response to heroin
  • Drugs and neurotransmitters
    • methylenedioxymethamphetamine (MMDA/Ecstasy/Molly) - damages axons (branch of neuron that releases its neurotransmitter into the synapse) that produces serotonin. Disruptions in serotonin neurotransmitter may underlie memory problems that are sometimes experienced by heavy users.
    • Methamphetamine damage to dopamine-releasing neurons can cause significant defects in thinking and motor skills
  • It is the system which nerves from these division innervates all involuntary structures of the body. Balanced functioning of these two systems plays a crucial role in maintaining homeostasis.
    SYMPATHETIC AND PARASYMPATHETIC SYSTEM
  • Neurotransmission
    Latin word "transmissio" meaning "passage, crossing" and from transmittere" meaning "send, let through."