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, Inhibitory; mood regulation, hunger, sleep

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

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