Neural and Hormonal Systems

• neuron


  nerve cell; building block of the nervous system
• synapse


  tiny gap where the neuron communicates chemically
• afferent neurons (sensory)


  transmit sensory info from receptors to the central nervous system
• efferent neurons (motor)


  transmit sensory info from the central nervous system to muscles
• interneurons


  connect afferent and efferent neurons within the central nervous system
• Dopamine


  Addictive reward system
• Serotonin


  non-addictive mood regulation
• Agonists


  Mimic endorphin effect, boost effect of neurotransmitters
• Antagonist


  Inhibit receptors, decrease amount of neurotransmitters
• Endorphins


  reception inhibitor (pain relief)
• The nervous system 


  body’s electrochemical communication system
• Peripheral nervous system


  Autonomic (involuntary)
• Sympathetic (nervous system)


  arousing
• Parasympathetic (nervous system)


  calming
• Central nervous system


  Spinal cord and brain, neural networks
• reflex arc


  simple reflexes (ex. Touching a hot stove)
• the endocrine system


  network of glands that produce and release hormones directly into the bloodstream, regulating various bodily functions and maintaining homeostasis.
• Action potential


  neural impulse; moving of signal down a neuron
• Refractory period


  neuron pauses after firing, with a break before being able to fire again
• All-or-none response


  the neuron either fires or does not fire; no in-between
• Threshold


  the level of stimulation required to trigger a neural impulse
• Neurotransmitters


  chemical messengers that cross synaptic gaps between neurons
• Adrenaline (epinephrin)


  hormone produced in adrenal glands; prepares body for physical action
• Leptin


  Hormone secreted by adipose (fat tissue; “stop eating“ hormone, regulates hunger and energy
• Ghrelin


  Hormone produced by stomach; “start eating” hormone, signals to brain when stomach is empty and it’s time to eat
• Melatonin


  Hormone produced by pineal gland; releases during the night to help us sleep
• Oxytocin 


  Hormone produced in pituitary gland; stimulates contraction of uterus and milk ducts in the breast
• Dopamine


  Excitatory/inhibitory; reward system/motivate, mood, emotion, arousal
• Serotonin


  Inhibitory; mood regulation, hunger, sleep
• Norepinephrine


  Excitatory; mobilizes brain and body for action (NO Rest)
• Glutamate


  Main excitatory; learning and long term memory
• GABA


  Main inhibitor; calms/winds you down (ex. for sleep)
• Substance P


  Excitatory; acts as the body's pain messenger by sending pain signals to the brain
• Acetylcholine (ACH)


  Excitatory; muscle movement, attention, arousal, memory