Chapter 2 Flashcards
neurons
cell body and branching fibers
dendrite
fibers receive info and conduct it toward cell body
axon
passage of the message
covered with myelin sheath
action potential
electrical charge travels down axon
fired by neuron
synapse
meeting point between neurons
neurotransmitters
chemical messengers released when action potential reaches terminals at axon’s end
(crosses synaptic gap and binds to receptors on receiving neuron)
reuptake
sending neuron reabsorbs excess neurotransmitters
morphine
elevates mood, eases pain (opiate drug)
dopamine
influences movement, learning, attention, emotion
seratonin
mood, hunger, sleep arousal
norepinephrine
alertness, arousal
Neurotransmitter and a hormone
agonist
similar to neurotransmitter
antagonist
bind to receptors, but block neurotransmitter
central nervous system (CNS)
brain, spinal cord
decision maker
peripheral nervous system (PNS)
gathers info, transmits CNS decisions to all other body parts
nerves
electrical cables formed of bundles of axons
links CNS to body’s sensory receptors, muscles, glands
sensory neurons
carry messages from body’s tissues; inward towards brain and spinal cord for processing
interneurons
process info within CNS (reflexes)
somatic nervous system
(PNS) enables voluntary control of skeletal muscles
autonomic nervous system
(PNS) controls glands, muscles in internal organs through sympathetic and parasympathetic divisions
sympathetic nervous system
(PNS) arouses and expends energy
parasympathetic nervous system
(PNS) calms, keeps steady internal state
spinal cord
(CNS) info highway; connects PNS to brain
endocrine system
glands secrete another form of chemical messengers (hormones) which travel through the bloodstream and affect other tissues
adrenal glands
kidney
fight or flight
hypothalamus
brain
controls pituitary gland